8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 11, 2006

ARCHSTONE-SMITH OPERATING TRUST

(Exact name of registrant as specified in charter)

Maryland	1-10272	90-0042860
(State or other jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

9200 E. Panorama Circle, Suite 400, Englewood, Colorado	80112
(Address of Principal Executive Offices)	(Zip Code)

(Registrant’s Telephone Number, including Area Code): (303) 708-5959

N/A
(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

TABLE OF CONTENTS

	ITEM 1.01. ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.
	ITEM 2.03. CREATION OF A DIRECT FINANCIAL OBLIGATION OR AN OBLIGATION UNDER AN OFF-BALANCE SHEET ARRANGEMENT OF A REGISTRANT.
	ITEM 3.03. MATERIAL MODIFICATION TO RIGHTS OF SECURITY HOLDERS.
	ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.
SIGNATURES
EXHIBIT INDEX
Underwriting Agreement
Third Supplemental Indenture
Form of 4.00% Note Due 2036
Opinion of Mayer, Brown, Rowe & Maw LLP regarding the legality of the Notes
Opinion of Mayer, Brown, Rowe & Maw LLP regarding certain tax matters
Registration Right Agreement
Letter Agreement

ITEM 1.01. ENTRY INTO A MATERIAL DEFINITIVE AGREEMENT.

     On July 11, 2006, Archstone-Smith Operating Trust (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Archstone-Smith Trust (“Trust”), Citigroup Global Markets Inc. and Morgan Stanley & Co. Incorporated, as representatives of the other underwriters named therein (collectively, the “Underwriters”), in connection with a public offering (the “Offering”) of $575,000,000 aggregate principal amount of the Company’s 4.00% Exchangeable Senior Notes due 2036 (the “Notes”). The Notes will bear interest at a rate of 4.00% per year and accrue interest from July 14, 2006. Interest on the Notes is payable semi-annually on July 15 and January 15 of each year, beginning on January 15, 2007. The Notes will mature on July 15, 2036. The Notes are exchangeable for common shares, par value $0.01 per share (“Common Shares”), of the Trust in accordance with the terms of the Notes. The closing of the Offering occurred on July 14, 2006.

     In connection with the Offering, the Company and the Trust have entered into a Registration Rights Agreement and a Letter Agreement relating to the issuance and registration of Common Shares upon the exchange of the Notes.

     A copy of the Underwriting Agreement, the Registration Rights Agreement and the Letter Agreement are filed as Exhibit 1.1, Exhibit 10.1 and Exhibit 10.2, respectively, to this Current Report on Form 8-K and are incorporated herein by reference.

     Affiliates of certain of the Underwriters have participated in the Company’s credit facilities. In addition, certain of the Underwriters and their respective affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for the Company for which they received or will receive customary fees and expenses.

ITEM 2.03. CREATION OF A DIRECT FINANCIAL OBLIGATION OR AN OBLIGATION UNDER AN OFF-BALANCE SHEET ARRANGEMENT OF A REGISTRANT.

     On July 14, 2006, the Company completed the Offering of the Notes. The Notes are effectively subordinated to the debts and liabilities of the Company’s subsidiaries.

ITEM 3.03. MATERIAL MODIFICATION TO RIGHTS OF SECURITY HOLDERS.

     In connection with the sale of the Notes, the Company executed a Third Supplemental Indenture. A copy of the Third Supplemental Indenture has been filed as Exhibit 4.1 to this form 8-K and is hereby incorporated by reference.

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.

     (a) Financial Statements of Businesses Acquired.

     Not applicable.

     (b) Pro Forma Financial Information.

     Not applicable.

     (c) Exhibits.

Exhibit 1.1	Underwriting Agreement
Exhibit 4.1	Third Supplemental Indenture

Exhibit 4.2	Form of 4.00% Note due 2036
Exhibit 5.1	Opinion of Mayer, Brown, Rowe & Maw LLP regarding the legality of the Notes
Exhibit 8.1	Opinion of Mayer, Brown, Rowe & Maw LLP regarding certain tax matters
Exhibit 10.1	Registration Rights Agreement, dated as of July 14, 2006, by and between Archstone-Smith Trust and Archstone-Smith Operating Trust
Exhibit 10.2	Letter Agreement, dated as of July 14, 2006, by and between Archstone-Smith Trust and Archstone-Smith Operating Trust
Exhibit 23.1	Consent of Mayer, Brown, Rowe & Maw LLP (included in Exhibit 5.1 and Exhibit 8.1)

SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Trust has duly caused this report to be filed on its behalf by the undersigned thereunto duly authorized.

	ARCHSTONE-SMITH OPERATING TRUST
	By:	/s/ Thomas S. Reif
Dated: July 17, 2006		Name:	Thomas S. Reif
		Title:	Group Vice President and Assistant General Counsel

EXHIBIT INDEX

No.	Description
Exhibit 1.1	Underwriting Agreement
Exhibit 4.1	Third Supplemental Indenture
Exhibit 4.2	Form of 4.00% Note due 2036
Exhibit 5.1	Opinion of Mayer, Brown, Rowe & Maw LLP regarding the legality of the Notes
Exhibit 8.1	Opinion of Mayer, Brown, Rowe & Maw LLP regarding certain tax matters
Exhibit 10.1	Registration Rights Agreement, dated as of July 14, 2006, by and between Archstone-Smith Trust and Archstone-Smith Operating Trust
Exhibit 10.2	Letter Agreement, dated as of July 14, 2006, by and between Archstone-Smith Trust and Archstone-Smith Operating Trust
Exhibit 23.1	Consent of Mayer, Brown, Rowe & Maw LLP (included in Exhibit 5.1 and Exhibit 8.1)

EX-1.1

Exhibit 1.1

ARCHSTONE–SMITH OPERATING TRUST

4.0% Exchangeable Senior Notes Due 2036

Underwriting Agreement

July 11, 2006

Citigroup Global Markets Inc.
Morgan Stanley & Co. Incorporated
As Representatives of the several Underwriters

c/o Citigroup Global Markets Inc.
388 Greenwich Street
New York, New York 10013

and

Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York 10036

Dear Ladies and Gentlemen:

          Archstone–Smith Operating Trust, a real estate investment trust organized under the laws of the State of Maryland (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to the underwriters named in Schedule I hereto (the “Underwriters”), $500,000,000 principal amount of its debt securities identified in Schedule I hereto as the Firm Securities (the “Firm Securities”), to be issued under the indenture specified in Schedule I hereto (the “Indenture”) between the Company and the Trustee identified in such Schedule (the

“Trustee”). The Company has also granted to the Underwriters the option to purchase up to $75,000,000 principal amount of such debt securities identified in Schedule I hereto as the Additional Securities (the “Additional Securities” and together with the Firm Securities, the “Securities”) to be issued under the Indenture, solely to cover overallotments.

     The Securities will be exchangeable in accordance with their terms and the terms of the Indenture into common shares of beneficial interest, par value $0.01 per share (the “Common Shares”) of Archstone-Smith Trust, a real estate investment trust organized under the laws of the State of Maryland (the “Trust”).

     Holders of the Securities will be entitled to the benefits of (i) a Letter Agreement, to be dated as of the Closing Date (as defined below) (the “Letter Agreement”), by and between the Company and the Trust, providing for the issuance of Common Shares upon exchange of the Securities and (ii) a Registration Rights Agreement, to be dated as of the Closing Date (as defined below) (the “Registration Rights Agreement”), by and between the Company and the Trust, providing for the registration under the Securities Act (as defined below) of any Common Shares that have not been registered under the Securities Act delivered upon exchange of the Securities.

          The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) in accordance with the provisions of the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement (File Number 333-133285) on Form S-3, relating to certain debt securities (the “Shelf Securities”) to be issued from time to time by the Company. The Company also has filed with, or proposes to file with, the Commission a prospectus supplement specifically relating to the Securities. The registration statement as amended to the date of this Agreement, including the information, if any, deemed pursuant to Rule 430A, 430B or 430C under the Securities Act to be part of the registration statement at the time of its effectiveness is hereinafter referred to as the “Registration Statement” and the related prospectus covering the Shelf Securities in the form first used (or made available upon request of purchasers pursuant to Rule 173 under the Securities Act) in connection with confirmation of sales of the Securities is hereinafter referred to as the “Basic Prospectus.” The Basic Prospectus, as supplemented by the prospectus supplement specifically relating to the Securities in the form first used (or made available upon request of purchasers pursuant to Rule 173 under the Securities Act) in connection with confirmation of sales of the Securities is hereinafter referred to as the “Prospectus,” and the term “Preliminary Prospectus” means any preliminary form of the Prospectus.

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          At the date and time that this Agreement is executed and delivered by the parties hereto.(the “Time of Sale”), the Company had prepared the following information (collectively, the “Time of Sale Information”): a Preliminary Prospectus dated July 10, 2006, and each “free writing prospectus” (as defined pursuant to Rule 405 under the Securities Act) listed on Annex A hereto.

          Any reference in this Agreement to the Registration Statement, any Preliminary Prospectus, the Time of Sale Information or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, which were filed under the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”), as of the effective date of the Registration Statement, the date of such Preliminary Prospectus, the Time of Sale or the date of the Prospectus, as the case may be and any reference to “amend”, “amendment” or “supplement” with respect to the Registration Statement, any Preliminary Prospectus, the Time of Sale Information or the Prospectus shall be deemed to refer to and include any documents filed after such date under the Exchange Act that are deemed to be incorporated by reference therein.

          The Company hereby agrees with the Underwriters as follows:

          1. (a) The Company agrees to issue and sell the Securities to the Underwriters as hereinafter provided, and the Underwriters, on the basis of the representations and warranties herein contained, but subject to the conditions hereinafter stated, agree to purchase from the Company the principal amount of Firm Securities set forth in Schedule I hereto at the purchase price set forth in Schedule I hereto plus accrued interest from the date specified in Schedule I hereto to the date of payment and delivery.

               (b) On the basis of the representations and warranties herein contained, but subject to its terms and conditions hereinafter stated, the Company agrees to sell to the Underwriters the Additional Securities set forth in Schedule I hereto, and the Underwriters shall have the right to purchase up to $75,000,000 aggregate principal amount of Additional Securities at the purchase price set forth in Schedule I, plus accrued interest, if any, to the applicable Option Closing Date (as defined below). You may exercise this right on behalf of the Underwriters, in whole

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or from time to time in part by giving written notice not later than 30 days after the date of this Agreement. Any exercise notice shall specify the number of Additional Securities to be purchased by you and the date on which such Additional Securities are to be purchased (each, an “Option Closing Date”). Each purchase date must be at least one business day after the written notice is given and may not be earlier than the Closing Date for the Firm Securities nor later than ten business days after the date of such notice.

          2. The Company understands that the Underwriters intend (i) to make a public offering of the Securities and (ii) initially to offer the Securities upon the terms set forth in the Time of Sale Information and the Prospectus.

          3. Payment for the Securities shall be made to the Company or to its order in immediately available funds on July 14, 2006 at 10:00 a.m at the place set forth in Schedule I hereto (or at such other time and place on the same or such other date, in any event not later than the third Business Day thereafter, as the Underwriters and the Company may agree in writing). The time and date of such payment and delivery with respect to the Firm Securities are referred to herein as the “Closing Date.”

          Payment for any Additional Securities shall be made to the Company or to its order in immediately available funds against delivery of such Additional Securities for the account of the Underwriters at 10:00 a.m., New York City time, on the Option Closing Date (or at such other time on the same or on such other date, in any event not later than the third business day thereafter, as the Underwriters and the Company may agree in writing).

          Payment for the Securities shall be made against delivery to the Underwriters on the Closing Date or the applicable Option Closing Date, as the case may be, of the Securities registered in such names and in such denominations as the Underwriters shall request not less than two full Business Days prior to the Closing Date or the applicable Option Closing Date, as the case may be, with any transfer taxes payable in connection with the transfer to the Underwriters duly paid by the Company. As used herein, the term “Business Day” means any day other than a Saturday or Sunday or a day on which banks are permitted or required to be closed in New York City. The certificates for the Securities will be made available for inspection and packaging by the Underwriters at least one full Business Day prior to the Closing Date or the applicable Option Closing Date, as the case may be, at such place in New York City as the Underwriters and the Company shall agree.

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          4. Each of the Company and the Trust, jointly and severally represents and warrants to the Underwriters that:

          (a) The Registration Statement is an “automatic shelf registration statement” as defined under Rule 405 of the Securities Act that has been filed with the Commission not earlier than three years prior to the date hereof, No stop order suspending the effectiveness of the Registration Statement has been issued and no notice pursuant to Rule 401(g)(2) of the Securities Act that would prevent its use shall have been issued and no proceeding for that purpose has been instituted or, to the knowledge of the Company, threatened by the Commission; and the Registration Statement and Prospectus (as amended or supplemented, if applicable) comply, or will comply, as the case may be, in all material respects with the Securities Act and the Trust Indenture Act of 1939, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Trust Indenture Act”), and do not and will not, as of the applicable effective date as to the Registration Statement and any amendment thereto and as of the date of the Prospectus and any amendment or supplement thereto contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, and in the case of the Prospectus, in the light of the circumstances under which they were made, not misleading, and the Prospectus, as first filed (if required) in accordance with Rule 424(b) and, as amended or supplemented at the Closing Date, if applicable, and on any date on which Additional Securities are purchased (if such date is not the Closing Date), will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; except that the foregoing representations and warranties shall not apply to (i) that part of the Registration Statement which constitutes the Statement of Eligibility and Qualification (Form T-1) under the Trust Indenture Act of the Trustee, and (ii) statements or omissions in the Registration Statement or the Prospectus made in reliance upon and in conformity with information relating to the Underwriters furnished to the Company or the Trust in writing by the Underwriters expressly for use therein, it being agreed and understood that the only such information is that described as such in the second paragraph of Section 8 hereof;

          (b) (i) At the time of filing the Registration Statement, (ii) at the time of the most recent amendment thereto for the purposes of complying with Section 10(a)(3) of the Securities Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Sections 13 or 15(d) of

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the Exchange Act or form of prospectus) and (iii) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c)) made any offer relating to the Securities in reliance on the exemption in Rule 163, the Company was a “well-known seasoned issuer” as defined in Rule 405. The Company has paid the registration fee for this offering pursuant to Rule 456(b)(1) or will pay such fees within the time period required by such rule (without regard to the proviso therein relating to the four business days extension to the payment deadline) and in any event prior to the Closing Date.

          (c) The Company is not an ineligible issuer as defined under the Securities Act, in each case at the times specified in Rule 164 under the Securities Act in connection with the offering of the Securities.

          (d) The documents incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when they became effective or were filed with the Commission, as the case may be, conformed in all material respects to the requirements of the Exchange Act or the Securities Act, as applicable, and none of such documents contained an untrue statement of a material fact or omitted to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when such documents become effective or are filed with the Commission, as the case may be, will conform in all material respects to the requirements of the Exchange Act, as applicable, and will not contain an untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading;

          (e) The Time of Sale Information, at the Time of Sale, did not, and at the Closing Date will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the foregoing representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information relating to the Underwriters furnished to the Company or the Trust in writing by the Underwriters expressly for use in such Time of Sale Information, it being agreed and understood that the only such information is that described as such in the second paragraph of Section 8 hereof. No statement of material fact included in the Prospectus has been omitted from the Time of Sale Information and no statement of material fact included in the Time of Sale Information that is required to be included in the Prospectus has been omitted therefrom;

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          (f) Intentionally Omitted.

          (g) Other than the Preliminary Prospectus and the Prospectus, the Company (including its agents and representatives, other than the Underwriters in their capacity as such) has not made, used, prepared, authorized, approved or referred to and will not prepare, make, use, authorize, approve or refer to any “written communication” (as defined in Rule 405 under the Securities Act) that constitutes an offer to sell or solicitation of an offer to buy the Securities (each such communication by the Company or its agents and representatives (other than a communication referred to in clause (i) below) an “Issuer Free Writing Prospectus”) other than (i) any document not constituting a prospectus pursuant to Section 2(a)(10)(a) of the Securities Act or Rule 134 under the Securities Act or (ii) the documents listed on Annex A hereto and other written communications approved in writing in advance by the Representatives. Each such Issuer Free Writing Prospectus complied in all material respects with the Securities Act, has been filed in accordance with the Securities Act (to the extent required thereby) and, when taken together with the Preliminary Prospectus accompanying, or delivered prior or subsequent to delivery of such Issuer Free Writing Prospectus, did not, and at the Closing Date and each Option Closing Date, as the case may be, will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the foregoing representation and warranty do not apply to any statements or omissions made in each such Issuer Free Writing Prospectus in reliance upon and in conformity with information relating to any Underwriter furnished to the Company or the Trust in writing by the Underwriters expressly for use in any Issuer Free Writing Prospectus, it being agreed and understood that the only such information is that described as such in the second paragraph of Section 8 hereof.

          (h) KPMG LLP, Independent Registered Public Accounting Firm, who has certified certain financial statements of the Company and the Trust and their respective subsidiaries included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus or incorporated by reference therein, are independent registered public accountants as required by the Securities Act;

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          (i) The financial statements and the related notes thereto of the Company, the Trust and their respective consolidated subsidiaries, included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus, present fairly the consolidated financial position of the Company, the Trust and their consolidated subsidiaries, and the entities which were acquired by or merged into the Company or the Trust (the “Company Group”), as of the dates indicated and the results of their operations and the changes in their consolidated cash flows for the period specified; the financial statements with respect to the properties acquired by the Company or or the Trust, as applicable or the entities which were acquired by or merged into the Company or the Trust, as applicable, together with related notes and schedules as set forth or incorporated by reference in the Registration Statement, the Time of Sale Information or the Prospectus, present fairly the financial position and the results of operations of such properties at the indicated dates and for the indicated periods; the foregoing financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applied on a consistent basis, and the supporting schedules included or incorporated by reference in the Registration Statement, the Time of Sale Information or the Prospectus present fairly the information required to be stated therein; the financial information and statistical data included or incorporated by reference in the Registration Statement, the Time of Sale Information or the Prospectus present fairly the information shown therein and have been compiled on a basis consistent with the financial statements presented therein; and the pro forma financial information and the related notes thereto, included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus has been prepared in accordance with the applicable requirements of the Securities Act and the Exchange Act, as applicable;

          (j) Since the respective dates as of which information is given in the Registration Statement, the Time of Sale Information and the Prospectus, there has not been any material adverse change, or any development involving a prospective material adverse change, in or affecting the general affairs, business prospects, management, financial position, shareholders’ equity or results of operations (a “Material Adverse Effect”) of the Company, the Trust and their respective Subsidiaries (as defined below), taken as a whole, otherwise than as set forth or contemplated in the Time of Sale Information and the Prospectus; and except as set forth or contemplated in the Time of Sale Information and the Prospectus neither the Company, the Trust nor any of their respective Subsidiaries has entered into any transaction or agreement (whether or not in the ordinary course of business) material to the Company, the Trust and their respective Subsidiaries taken as a whole;

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          (k) The Company has been duly organized and is validly existing as a real estate investment trust of unlimited duration with transferable shares of beneficial interest in good standing under the laws of the State of Maryland, with power and authority (trust or other) to own its properties and conduct its business as described in the Time of Sale Information and the Prospectus, and has been duly qualified for the transaction of business (where such qualification is available) and is in good standing under the laws of each other jurisdiction in which it owns or leases properties, or conducts any business, where such qualification is required, other than where the failure to be so qualified or in good standing would not have a Material Adverse Effect on the Company and its Subsidiaries taken as a whole; The Trust is the sole trustee of the Company and owned approximately 86.5% of the Company at March 31, 2006;

          (l) The Trust has been duly organized and is validly existing as a real estate investment trust of unlimited duration with transferable shares of beneficial interest in good standing under the laws of the State of Maryland, with power and authority (trust or other) to own its properties and conduct its business as described in the Time of Sale Information and the Prospectus, and has been duly qualified for the transaction of business (where such qualification is available) and is in good standing under the laws of each other jurisdiction in which it owns or leases properties, or conducts any business, where such qualification is required, other than where the failure to be so qualified or in good standing would not have a Material Adverse Effect on the Company and its Subsidiaries taken as a whole;

          (m) Each subsidiary (within the meaning of the Securities Act) of the Company and the Trust (the “Subsidiaries”) has been duly incorporated or organized and is validly existing as a corporation, limited liability company or limited partnership, as the case may be, under the laws of its jurisdiction of incorporation, formation or organization, with power and authority (corporate or other) to own its properties and conduct its business as described in the Time of Sale Information and the Prospectus, and has been duly qualified as a foreign entity or limited partnership, as the case may be, for the transaction of business and is in good standing under the laws of each jurisdiction in which it owns or leases properties or conducts any business where such qualification is required, other than where the failure to be so qualified or in good standing would not have a Material Adverse Effect on the Company, the Trust and their respective subsidiaries taken as a whole;

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and all the outstanding equity securities of each such subsidiary have been duly authorized and validly issued, are fully-paid and non-assessable, and (except for general partnership interests or in the case of foreign Subsidiaries, for directors’ qualifying shares) are owned by the Company or the Trust, directly or indirectly, free and clear of all liens, encumbrances, security interests and claims other than the Company’s pledge of the shares of two of its German subsidiaries as collateral for loans it obtained to purchase portfolios of German properties;

          (n) Neither the Company, the Trust nor any of their respective Subsidiaries is party to any joint venture with any other entity, except (i) as described or incorporated by reference in the Time of Sale Information and the Prospectus or (ii) such joint ventures which are not material to the general affairs, business prospects, management, financial position, shareholders’ equity or results of operations of the Company, the Trust and their respective Subsidiaries, taken as a whole;

          (o) This Agreement has been duly authorized, executed and delivered by the Company and the Trust and constitutes the valid and binding agreement of the Company and the Trust, enforceable against the Company and the Trust in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity, and except as rights to indemnity and contribution hereunder may be limited by applicable law;

          (p) The Letter Agreement and the Registration Rights Agreement have been duly authorized and, when executed and delivered by the Company and the Trust, will constitute the valid and binding agreement of the Company and the Trust, enforceable against the Company and the Trust in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity, and except as rights to indemnity and contribution hereunder may be limited by applicable law;

          (q) The Securities have been duly authorized, and, when issued, authenticated and delivered pursuant to this Agreement and the Indenture, will have been duly executed, authenticated, issued and delivered and will constitute valid and binding obligations of the Company entitled to the benefits provided by the Indenture and enforceable against the Company in accordance with their terms,

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subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity; the Base Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity; the First Supplemental Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity; the Third Supplemental Indenture has been duly authorized by the Company and, when executed and delivered by the parties thereto, will constitute a valid and binding agreement enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and the effect of general principles of equity; the Indenture has been duly qualified under the Trust Indenture Act; and the Securities and the Indenture will conform to the descriptions thereof in the Time of Sale Information and Prospectus in all material respects.

          (r) Neither the Company, the Trust nor any of their respective Subsidiaries is, nor with the giving of notice or lapse of time or both would be, in violation of or in default under, (i) its Amended and Restated Declaration of Trust or By-Laws or other governing documents, as applicable, or (ii) any joint venture agreement, partnership agreement or other governing instruments or any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company, the Trust or any of their respective Subsidiaries is a party or by which any of them or any of their respective properties is bound, except in the case of clause (ii) for violations and defaults which individually and in the aggregate would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole.

          (s) The issue and sale of the Securities, the reservation of the Common Shares for issuance upon exchange of the Securities and the performance by the Company and the Trust of all of the provisions and its obligations under the Securities, the Indenture, this Agreement, the Letter Agreement, the Registration Rights Agreement and the consummation of the transactions herein and therein

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contemplated will not conflict with or result in a breach of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other material agreement or instrument to which the Company, the Trust or any of their respective Subsidiaries is a party or by which the Company, the Trust or any of their respective Subsidiaries is bound or to which any of the property or assets of the Company, the Trust or any of their respective Subsidiaries is subject, nor will any such action result in any violation of the provisions of the respective Amended and Restated Declaration of Trust or the By-Laws of the Company or the Trust or any applicable law or statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company, the Trust, their respective Subsidiaries or any of their respective properties; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Securities or the consummation by the Company or the Trust of the transactions contemplated by the Indenture, this Agreement, the Letter Agreement and the Registration Rights Agreements, except such consents, approvals, authorizations, registrations or qualifications as have been obtained under the Securities Act, the Trust Indenture Act and as may be required under state securities or Blue Sky Laws in connection with the purchase and distribution of the Securities by the Underwriters or consents, the failure of which to obtain would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole, or a material adverse effect on the consummation of the transactions contemplated by this Agreement or the Indenture or on the validity and enforceability of the Securities and the Indenture;

          (t) Neither the Company nor the Trust is an “investment company” or an entity “controlled” by an “investment company”, as such terms are defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”);

          (u) Other than as set forth or contemplated in the Time of Sale Information and the Prospectus, there are no legal or governmental proceedings pending or, to the knowledge of the Company or the Trust, threatened to which the Company, the Trust any of their respective Subsidiaries is or may be a party or to which any property of the Company, the Trust or any of their respective Subsidiaries is or may be the subject which, if determined adversely to the Company, the Trust or any of their respective Subsidiaries, could individually or in the aggregate reasonably be expected to have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole, and, to the best of the Company’s and the

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Trust’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others; and there are no contracts or other documents of a character required to be filed as an exhibit to the Registration Statement or required to be described in the Registration Statement, the Time of Sale Information or the Prospectus which are not filed or described as required;

          (v) The Company’s authorized, issued and outstanding shares of beneficial interest is as set forth or incorporated by reference in the Time of Sale Information and Prospectus as of the date stated in each such item; and all of the issued shares of beneficial interest have been duly and validly authorized and issued, are fully paid and non-assessable;

          (w) The Trust’s authorized, issued and outstanding shares of beneficial interest are as set forth or incorporated by reference in the Time of Sale Information and Prospectus as of the date stated in each such item; and all of the issued shares of beneficial interest have been duly and validly authorized and issued, are fully paid and non-assessable;

          (x) The Company, the Trust and each of their respective Subsidiaries have good and marketable title in fee simple to all real property described in the Registration Statement, Time of Sale Information and Prospectus as owned by them and good and marketable title to all personal property owned by them, in each case free and clear of all liens, encumbrances and defects except such as are described in the Time of Sale Information and Prospectus or such as do not materially affect the value of such property and do not interfere with the use made and proposed to be made of such property by the Company, the Trust and each of their respective subsidiaries; and any real property and buildings held under lease by the Company, the Trust and their respective Subsidiaries and described in the Registration Statement, Time of Sale Information and Prospectus are held by them under valid and subsisting leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such property and buildings by the Company, the Trust and their respective Subsidiaries;

          (y) The Company, the Trust and their respective Subsidiaries taken as a whole carry, or are covered by, insurance in such amounts and covering such risks as is adequate for the conduct of their business and the value of their properties;

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          (z) For the fiscal year ended December 31, 1996 through the period ending on and including October 29, 2001, the Company met the requirements for qualification as a real estate investment trust under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”);

          (aa) For the period beginning October 30, 2001 and ending on and including the date hereof, the Company has operated in a manner to be classified as a partnership, and not as an association or partnership taxable as a corporation, for federal income tax purposes;

          (bb) For the fiscal year ended December 31, 2001 and all periods thereafter ending on and including the date hereof, the Trust met the requirements for qualification as a real estate investment trust under Sections 856 through 860 of the Code;

          (cc) All material Tax returns required to be filed by the Company Group have been filed and all such returns are true, complete, and correct in all material respects. All material Taxes that are due or claimed to be due from the Company Group have been paid other than those (i) currently payable without penalty or interest or (ii) being contested in good faith and by appropriate proceedings and for which, in the case of both clauses (i) and (ii), adequate reserves have been established on the books and records of the Company Group in accordance with GAAP. There are no proposed material Tax assessments against the Company Group. To the best knowledge and belief of the Company, the accruals and reserves on the books and records of the Company Group in respect of any material Tax liability for any Taxable period which liability has not been finally determined are adequate to meet any assessments of Tax for any such period. For purposes of this Agreement, the term “Tax” and “Taxes” shall mean all federal, state, local and foreign taxes, and other assessments of a similar nature (whether imposed directly or through withholding), including any interest, additions to tax, or penalties applicable thereto;

          (dd) Each of the Company, the Trust and their respective Subsidiaries owns, possesses or has obtained all licenses, permits, certificates, consents, orders, approvals and other authorizations from, and has made all declarations and filings with, all federal, state, local and other governmental authorities (including foreign regulatory agencies), all self-regulatory organizations and all courts and other tribunals, domestic or foreign, necessary to own or lease, as the case may be, and to operate its properties and to carry on its business as

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conducted as of the date hereof, except in each case where the failure to obtain licenses, permits, certificates, consents, orders, approvals and other authorizations, or to make all declarations and filings, would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole, and none of the Company, the Trust any of their respective Subsidiaries has received any notice of any proceeding relating to revocation or modification of any such license, permit, certificate, consent, order, approval or other authorization, except as described in the Registration Statement, the Time of Sale Information and the Prospectus and except, in each case, where such revocation or modification would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole; and the Company, the Trust and each of their respective Subsidiaries are in material compliance with all laws, rules and regulations relating to the conduct of their respective businesses as conducted as of the date hereof, except where noncompliance with such laws or regulations would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole;

          (ee) Except as disclosed in the Time of Sale Information and Prospectus, the Company, the Trust and their respective Subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their business, (iii) are in compliance with all terms and conditions of any such permit, license or approval and (iv) have no knowledge of the unlawful presence of any hazardous substances, hazardous materials, toxic substances or waste materials on any of the properties owned by them, or of any unlawful spills, releases, discharges or disposal of such hazardous materials that have occurred or are presently occurring off such properties as a result of any construction on or operation and use of such properties, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals or unlawful presence of hazardous materials or occurrence would not, singly or in the aggregate, result in a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole;

          (ff) The mortgages and deeds of trust encumbering the properties and assets described in the Time of Sale Information and the Prospectus (i) are not convertible and neither the Company, the Trust nor any of their Subsidiaries holds a participating interest therein, and (ii) are not cross-defaulted or cross-collateralized to any property not owned by the Company, the Trust or any of their Subsidiaries;

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          (gg) Subsequent to the respective dates as of which information is given in the Time of Sale Information and the Prospectus, (i) the Company has not purchased any of its outstanding shares of beneficial interest (other than the redemption of common units in accordance with the terms of the Company’s Amended and Restated Declaration of Trust), nor declared, paid or otherwise made any dividend or distribution of any kind on its shares of beneficial interest other than regular periodic dividends on its shares of beneficial interest (preferred or common); and (ii) there has not been any material change in the shares of beneficial interest, short-term debt or long-term debt of the Company, except in either case as described in or contemplated by the Time of Sale Information and the Prospectus;

          (hh) Subsequent to the respective dates as of which information is given in the Time of Sale Information and Prospectus, (i) the Trust has not purchased any of its outstanding shares of beneficial interest, nor declared, paid or otherwise made any dividend or distribution of any kind on its shares of beneficial interest other than regular periodic dividends on its shares of beneficial interest (preferred or common); and (ii) there has not been any material change in the shares of beneficial interest, short-term debt or long-term debt of the Trust, except in either case as described in or contemplated by the Time of Sale Information and the Prospectus;

          (ii) Neither the Company nor the Trust has taken or will take, directly or indirectly, any action designed to, or that might be reasonably expected to, cause or result in stabilization or manipulation of the price of the Securities, and neither the Company nor the Trust has distributed and the Company and the Trust have agreed not to distribute any prospectus or other offering material in connection with the offering and sale of the Securities other than the Prospectus, any preliminary prospectus filed with the Commission or other material permitted by the Securities Act;

          (jj) The Company, the Trust and each of their respective Subsidiaries maintains a system of internal accounting controls sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences;

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          (kk) Each of the Company and the Trust has established and maintains “disclosure controls and procedures” (as defined in Rule 13a-15(e) under the Exchange Act) that are effective in ensuring that information required to be disclosed by the Company or the Trust, as applicable, in the reports that each of them files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the rules and forms of the Commission, including, without limitation, controls and procedures designed to ensure that information required to be disclosed by the Company or the Trust, as applicable, in the reports that each of them files or submits under the Exchange Act is accumulated and communicated to the Company’s management or the Trust’s management, as applicable, including its principal executive officer or officers and its principal financial officer or officers, as appropriate to allow timely decisions regarding required disclosure, and each of the Company and the Trust is otherwise in compliance in all material respects with all applicable effective provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations issued thereunder by the Commission in connection therewith, including, without limitation, Section 402 related to loans and Section 906 related to certifications; and

          (ll) The Common Shares initially issuable upon exchange for the Securities have been duly authorized and reserved for issuance, and, if and when issued and delivered in accordance with the provisions of the Securities, the Indenture and the Letter Agreement, will be duly and validly issued and fully paid and nonassessable; the Common Shares conform to the description thereof incorporated by reference in the Time of Sale Information and the Prospectus.

          5. Each of the Company and the Trust covenants and agrees with the Underwriters as follows:

          (a) The Company will file (i) the Prospectus with the Commission within the time periods specified by Rule 424(b) and Rule 430A, 430B or 430C under the Securities Act and (ii) any Issuer Free Writing Prospectus to the extent required by Rule 433 under the Securities Act and will pay the registration fee for this offering pursuant to Rule 456(b)(1) under the Securities Act within the time period required by such rule (without regard to the proviso therein relating to the four business days extension to the payment deadline) and in any event prior to the Closing Date;

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          (b) The Company will deliver to the Underwriters and counsel for the Underwriters, at the expense of the Company, a signed copy of the Registration Statement (as originally filed) and each amendment thereto, in each case including exhibits and documents incorporated by reference therein and, during the period mentioned in paragraph (e) below, to the Underwriters as many copies of the Time of Sale Information, the Prospectus (including all amendments and supplements thereto) and documents incorporated by reference therein and each Issuer Free Writing Prospectus (to the extent not previously delivered) as the Underwriters may reasonably request;

          (c) Before preparing, using, authorizing, approving, referring to or filing any Issuer Free Writing Prospectus, and before filing any amendment or supplement to the Registration Statement or Prospectus, furnish to the Underwriters a copy of any proposed Issuer Free Writing Prospectus, amendment or supplement to the Registration Statement or the Prospectus, for review by the Underwriters, and not to prepare, use, authorize, approve, refer to or file any such Issuer Free Writing Prospectus or file any such proposed amendment or supplement to which the Underwriters reasonably objects;

          (d) The Company and Trust will file promptly all reports and any definitive proxy or information statements required to be filed by the Company or the Trust with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act for so long as the delivery of a prospectus is required in connection with the offering or sale of the Securities, and during such same period, will advise the Underwriters promptly, and to confirm such advice in writing, (i) when any amendment to the Registration Statement or any Issuer Free Writing Prospectus shall have become effective, (ii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for any additional information, (iii) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any notice pursuant to Rule 401(g)(2) of the Act that would prevent its use or the institution or threatening of any proceeding for that purpose and (iv) of the receipt by the Company of any notification with respect to any suspension of the qualification of the Securities for offer and sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and each of the Company and the Trust will use their best efforts to prevent the issuance of any such stop order or notification and, if issued, to obtain as soon as possible the withdrawal thereof and (v) of the occurrence of any event during the period specified in paragraph (e) below as a result of which the Prospectus, the

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Time of Sale Information or any Issuer Free Writing Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus, the Time of Sale Information or any such Issuer Free Writing Prospectus is delivered to a purchaser, not misleading;

          (e) (1) If, during such period after the first date of the public offering of the Securities as in the reasonable opinion of counsel for the Underwriters a prospectus relating to the Securities is required by law to be delivered (or required to be delivered but for Rule 172 of the Securities Act) in connection with sales by an Underwriter or dealer, any event shall occur as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered to a purchaser, not misleading, or if it is necessary to amend or supplement the Prospectus to comply with law, and such amendment or supplement, reasonably satisfactory in all respects to the Underwriters, the Company will forthwith prepare and furnish, at the expense of the Company, to the Underwriters and to the dealers (whose names and addresses the Underwriters will furnish to the Company) to which Securities may have been sold by the Underwriters and to any other dealers upon request, such amendments or supplements to the Prospectus as may be necessary so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances under which they were made, be misleading or so that the Prospectus will comply with law and (2) if at any time prior to the Closing Date (or any Option Closing Date) (i) any event shall occur or condition shall exist as a result of which the Time of Sale Information as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances, not misleading or (ii) it is necessary to amend or supplement the Time of Sale Information to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission (to the extent required) and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Time of Sale Information as may be necessary so that the statements in the Time of Sale Information as so amended or supplemented will not, in the light of the circumstances under which they were made, be misleading or so that the Time of Sale Information will comply with law.

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          (f) The Company and the Trust will comply with the Securities Act and the regulations thereunder and the Exchange Act and the rules and regulations thereunder so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Prospectus, except where the failure to comply will not adversely affect the distribution of the Securities.

          (g) The Company will endeavor to qualify the Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Underwriters shall reasonably request and to continue such qualification in effect so long as reasonably required for distribution of the Securities and to pay all fees and expenses (including fees and disbursements of counsel to the Underwriters) reasonably incurred in connection with such qualification and in connection with the determination of the eligibility of the Securities for investment under the laws of such jurisdictions as the Underwriters may designate; provided that the Company shall not be required to file a general consent to service of process in any jurisdiction or to qualify to do business in any jurisdiction where it is not so qualified;

          (h) The Company and the Trust will make generally available to its security holders and to the Underwriters as soon as practicable an earning statement covering a period of at least twelve months beginning with the first fiscal quarter of the Company and the Trust occurring after the effective date of the Registration Statement, which shall satisfy the provisions of Section 11(a) of the Securities Act and Rule 158 of the Commission promulgated thereunder;

          (i) The Company will operate in a manner to continue to be classified as a partnership, and not as an association or partnership taxable as a corporation, for federal income tax purposes;

          (j) The Trust will operate in a manner to continue to qualify as a real estate investment trust under Section 856 through 860 of the Code.

          (k) So long as the Securities are outstanding, the Company will furnish to the Underwriters copies of all reports or other communications (financial or other) furnished to holders of Securities, and copies of any reports and financial statements furnished to or filed with the Commission or any national securities exchange;

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          (l) During the period beginning on the date hereof and continuing to and including the Business Day following the Closing Date, neither the Company nor the Trust will offer, sell, contract to sell or otherwise dispose of any debt securities of, or guaranteed by, the Company which are substantially similar to the Securities without the Underwriters’ prior written consent;

          (m) The Company will use the net proceeds of the offering of the Securities in the manner specified in the Registration Statement, the Time of Sale Information and the Prospectus under “Use of Proceeds;”

          (n) As long as any Securities are outstanding, neither the Company nor the Trust will be or become an open-end investment trust, unit investment trust, closed-end investment company or face-amount certificate company that is or is required to be registered under the Investment Company Act;

          (o) The Company will pay all costs and expenses incident to the performance of its and the Trust’s obligations hereunder, including without limiting the generality of the foregoing, all costs and expenses (i) incident to the preparation, issuance, execution, authentication and delivery of the Securities, including any expenses of the Trustee, (ii) incident to the preparation, printing and filing under the Securities Act of the Registration Statement, the Time of Sale Information and the Prospectus (including in each case all exhibits, amendments and supplements thereto), (iii) incurred in connection with the registration or qualification and determination of eligibility for investment of the Securities under the laws of such jurisdictions as the Underwriters may designate (including reasonable fees of counsel for the Underwriters and their disbursements), (iv) related to any filing with National Association of Securities Dealers, Inc. in respect of the Securities, (v) in connection with the listing of the Common Shares on the New York Stock Exchange, (vi) in connection with the printing (including word processing and duplication costs) and delivery of this Agreement, the Indenture, the Preliminary and Supplemental Blue Sky Memoranda and any Legal Investment Survey and the furnishing to the Underwriters and dealers of copies of the Registration Statement, the Time of Sale Information and the Prospectus, including mailing and shipping, as herein provided and (vii) payable to rating agencies in connection with the rating of the Securities;

          (p) The Company will retain, pursuant to reasonable procedures developed in good faith, copies of each Issuer Free Writing Prospectus that is not filed with the Commission in accordance with Rule 433(g) under the Securities Act;

          (q) Without the prior written consent of the Underwriter, the Trust will not, during the period ending 60 days after the date of the Prospectus, (i) offer,

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pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any Common Shares or any securities convertible into or exercisable or exchangeable for Common Shares; or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Shares, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Shares or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (a) the issuance of any Common Shares to holders of the Securities upon exchange of the Securities, (b) the issuance by the Trust of Common Shares upon the redemption of Class A-1 common units of beneficial interest, par value $0.01 per unit (“Class A-1 Units”), of the Company in accordance with the Amended and Restated Declaration of Trust of the Company, (c) the issuance by the Trust of Common Shares upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof which are described in the Prospectus, (d) the grant of options to purchase Common Shares pursuant to the Trust’s or the Company’s existing employee or trustee benefit plans as in effect on the date hereof, (e) the issuance of Class B common units of beneficial interest, par value $0.01 per unit (together with the Class A-1 Units, the “Units”), of the Company in connection with the acquisition of property, directly or indirectly, by the Company or (f) the issuance by the Trust of Common Shares or by the Company of Units in accordance with the Trust’s dividend reinvestment and share purchase plan;

          (r) The Trust shall reserve and keep available at all times free as preemptive rights, a sufficient number of Common Shares for the purpose of enabling the Company to deliver, at its election, Common Shares upon the exchange of the Securities; and

          (s) The Company shall prepare a final term sheet, containing solely a description of the Securities, substantially in the form of Annex B hereto and approved by the Underwriters and shall file such term sheet pursuant to Rule 433(d) within the time required by such Rule.

          6. The obligations of the Underwriters hereunder shall be subject to the following conditions:

          (a) the representations and warranties of the Company and the Trust contained herein are true and correct as of the date hereof, as of the Closing Date and as of each Option Closing Date as if made on and as of the date hereof, of

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the Closing Date and as of each Option Closing Date, and each of the Company and the Trust shall have complied with all agreements and all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date or any such Option Closing Date;

          (b) the Prospectus and each Issuer Free Writing Prospectus shall have been timely filed with the Commission under the Securities Act (in the case of an Issuer Free Writing Prospectus, to the extent required by Rule 433 under the Securities Act) and in accordance with Section 5(a) hereof; no stop order suspending the effectiveness of the Registration Statement shall be in effect, and no notice pursuant to Rule 401(g)(2) of the Act that would prevent its use shall have been issued and no proceedings for such purpose shall be pending before or threatened by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to the reasonable satisfaction of the Underwriters;

          (c) subsequent to the execution and delivery of this Agreement and prior to the Closing Date and each Option Closing Date, there shall not have occurred any downgrading, nor shall any notice have been given of (i) any intended or potential downgrading or (ii) any review or possible change that does not indicate an improvement, in the rating accorded any securities of or guaranteed by the Company or the Trust by any “nationally recognized statistical rating organization”, as such term is defined for purposes of Rule 436(g)(2) under the Securities Act;

          (d) since the respective dates as of which information is given in the Time of Sale Information (excluding any amendment or supplement thereto) and the Prospectus (excluding any amendment or supplement thereto) there shall not have been any material change in the shares of beneficial interest, short-term debt or long-term debt of the Company or the Trust or any Material Adverse Effect with respect to the Company or the Trust and their respective Subsidiaries, taken as a whole, otherwise than as set forth or contemplated in the Time of Sale Information (excluding any amendment or supplement thereto) and the Prospectus (excluding any amendment or supplement thereto), the effect of which in the judgment of the Underwriters makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Securities on the terms and in the manner contemplated in the Time of Sale Information and the Prospectus;

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          (e) the Underwriters shall have received on and as of the Closing Date a certificate of two officers of the Company, at least one of whom is a Chairman, Chief Executive Officer, Chief Financial Officer or Vice President of the Company satisfactory to the Underwriters to the effect set forth in subsections (a) through (c) of this Section and to the further effect that there has not occurred any Material Adverse Effect with respect to the Company and its Subsidiaries taken as a whole from that set forth or contemplated in the Registration Statement, the Time of Sale Information and the Prospectus;

          (f) the Underwriters shall have received on and as of the Closing Date a certificate of two officers of the Trust, at least one of whom is a Chairman, Chief Executive Officer, Chief Financial Officer or Vice President of the Trust satisfactory to the Underwriters to the effect set forth in subsections (a) through (c) of this Section and to the further effect that there has not occurred any Material Adverse Effect with respect to the Trust and its Subsidiaries taken as a whole from that set forth or contemplated in the Registration Statement, the Time of Sale Information and the Prospectus;

          (g) Mayer, Brown, Rowe & Maw LLP, Counsel of the Company and the Trust, shall have furnished to the Underwriters their written opinion, dated the Closing Date and, if applicable, each Option Closing Date, in form and substance reasonably satisfactory to the Underwriters, to the effect set forth in Annex C.

          (h) Caroline Brower, General Counsel of the Company and the Trust, shall have furnished to the Underwriters her written opinion, dated the Closing Date, in form and substance reasonably satisfactory to the Underwriters, to the effect set forth in Annex D.

          (i) on the date of execution of this Agreement and also on the Closing Date and each Option Closing Date, KPMG LLP, Independent Registered Public Accounting Firm, shall furnish to the Underwriters letters, dated such respective dates of delivery, in form and substance reasonably satisfactory to the Underwriters, containing statements and information of the type customarily included in accountants “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in or incorporated by reference in the Registration Statement , the Time of Sale Information and the Prospectus, provided that the letter delivered on the Closing Date or any applicable Option Closing Date shall use a “cut-off” date no more than three business days prior to the Closing Date or such Option Closing Date, as the case may be;

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          (j) The Common Shares have been or by the Closing Date will be approved for listing on the New York Stock Exchange, subject to notice of issuance.

          (k) the Underwriters shall have received on and as of the Closing Date an opinion of Skadden, Arps, Slate, Meagher & Flom LLP, counsel to the Underwriters, with respect to the validity of the Indenture and the Securities, the Registration Statement, the Time of Sale Information, the Prospectus and other related matters as the Underwriters may reasonably request, and such counsel shall have received such papers and information as they may reasonably request to enable them to pass upon such matters;

          (l) on or prior to the Closing Date, the Company shall have furnished to the Underwriters such further certificates and documents as the Underwriters shall reasonably request; and

          (m) the Underwriters shall have received “lock-up” agreements, each substantially in the form of Annex E hereto, from the executive officers and trustees of the Trust relating to sales and certain other dispositions of Common Shares or certain other securities, and all of such “lock-up” agreements, delivered to you on or before the date hereof, shall be in full force and effect on the Closing Date.

          7. Each Underwriter hereby represents and agrees that

          (a) it has not and will not use, authorize use of, refer to, or participate in the planning for use of, any “free writing prospectus”, as defined in Rule 405 under the Securities Act (which term includes use of any written information furnished to the Commission by the Company and not incorporated by reference into the Registration Statement and any press release issued by the Company) other than (i) a free writing prospectus that contains no “issuer information” (as defined in Rule 433(h)(2) under the Securities Act) that was not included (including through incorporation by reference) in the Preliminary Prospectus or a previously filed Issuer Free Writing Prospectus, (ii) any Issuer Free Writing Prospectus listed on Annex A or prepared pursuant to Section 4(d) or Section 5(c) above, or (iii) any free writing prospectus prepared by such underwriter and approved by the Company in advance in writing (each such free writing prospectus referred to in clauses (i) or (iii), an “Underwriter Free Writing Prospectus”).

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          (b) it has not and will not distribute any Underwriter Free Writing Prospectus referred to in clause (a) (i) in a manner reasonably designed to lead to its broad unrestricted dissemination.

          (c) it has not and will not, without the prior written consent of the Company, use any free writing prospectus that contains the final terms of the Securities unless such terms have previously been included in a free writing prospectus filed with the Commission; provided that Underwriters may use a term sheet substantially in the form of Annex B hereto without the consent of the Company; provided further that any Underwriter using such term sheet shall notify the Company, and provide a copy of such term sheet to the Company, prior to, or substantially concurrently with, the first use of such term sheet.

          (d) it will, pursuant to reasonable procedures developed in good faith, retain copies of each free writing prospectus used or referred to by it, in accordance with Rule 433 under the Securities Act.

          (e) it is not subject to any pending proceeding under Section 8A of the Securities Act with respect to the offering and sale of the Securities (and will promptly notify the Company if any such proceeding against it is initiated during the Prospectus Delivery Period).

          8. The Company agrees to indemnify and hold harmless the Underwriters and each person, if any, who controls the Underwriters within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including without limitation the legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted) arising out of or caused by (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement arising out of or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein, not misleading or (ii) any untrue statement or alleged untrue statement of a material fact contained in the Prospectus (or any amendment or supplement thereto), any Issuer Free Writing Prospectus or any Time of Sale Information, or caused by any omission or alleged omission to state therein a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, except insofar as such losses, claims, damages or liabilities arising out of or are caused by any untrue statement or omission or alleged untrue statement or omission made in reliance upon

26

and in conformity with information relating to the Underwriters furnished to the Company in writing by the Underwriters expressly for use therein, it being agreed and understood that the only such information is that which is described as such in the second paragraph of this Section;.

          The Underwriters agree, severally and not jointly, to indemnify and hold harmless the Company, its trustees, its officers who sign the Registration Statement, and each person who controls the Company within the meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act, to the same extent as the foregoing indemnity from the Company to the Underwriters, but only with reference to information relating to the Underwriters furnished to the Company in writing by the Underwriters expressly for use in the Registration Statement, the Prospectus, any amendment or supplement thereto, or any preliminary prospectus. For purposes of this Section 8 and Sections 4(a), 4(e) and 4(g), the only written information furnished by the Underwriters to the Company expressly for use in the Registration Statement, the Time of Sale Information, any Issuer Free Writing Prospectus or the Prospectus is the information in the fifth, ninth, tenth and eleventh paragraphs (other than with respect to the Company) under the caption “Underwriting” in the prospectus supplement.

          If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against any person in respect of which indemnity may be sought pursuant to either of the two preceding paragraphs, such person (the “Indemnified Person”) shall promptly notify the person against whom such indemnity may be sought (the “Indemnifying Person”) in writing, and the Indemnifying Person, upon request of the Indemnified Person, shall retain counsel reasonably satisfactory to the Indemnified Person to represent the Indemnified Person and any others the Indemnifying Person may designate in such proceeding and shall pay the fees and expenses of such counsel related to such proceeding. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary, (ii) the Indemnifying Person has failed within a reasonable time to retain counsel reasonably satisfactory to the Indemnified Person or (iii) the named parties in any such proceeding (including any impleaded parties) include both the Indemnifying Person and the Indemnified Person and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood that the Indemnifying Person shall not, in connection with any

27

proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such fees and expenses shall be reimbursed as they are incurred. Any such separate firm for the Underwriters and such control persons of the Underwriters shall be designated in writing by the Representatives and any such separate firm for the Company, the officers of the Company who sign the Registration Statement and such control persons of the Company or its authorized representatives shall be designated in writing by the Company. The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify any Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested an Indemnifying Person to reimburse the Indemnified Person for fees and expenses of counsel as contemplated by the third sentence of this paragraph, the Indemnifying Person agrees that it shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by such Indemnifying Person of the aforesaid request and (ii) such Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement; provided that if it is ultimately determined that an Indemnified Person was not entitled to indemnification hereunder, such person shall be responsible for repaying or reimbursing such amounts to the Indemnifying Person. No Indemnifying Person shall, without the prior written consent of the Indemnified Person, effect any settlement of any pending or threatened proceeding in respect of which any Indemnified Person is or could have been a party and indemnity could have been sought hereunder by such Indemnified Person, unless such settlement includes an unconditional release of such Indemnified Person from all liability on claims that are the subject matter of such proceeding.

          If the indemnification provided for in the first and second paragraphs of this Section 8 is unavailable to an Indemnified Person in respect of any losses, claims, damages or liabilities referred to therein, then each Indemnifying Person under such paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall contribute to the amount paid or payable by such Indemnified Person as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Securities or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such

28

proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same respective proportions as the net proceeds from the offering of such Securities (before deducting expenses) received by the Company and the total underwriting discounts received by the Underwriters bear to the aggregate public offering price of the Securities. The relative fault of the Company on the one hand and the Underwriters on the other shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

          The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 8 were determined by pro rata allocation or by any other method of allocation that does not take account of the equitable considerations referred to in the immediately preceding paragraph. The amount paid or payable by an Indemnified Person as a result of the losses, claims, damages and liabilities referred to in the immediately preceding paragraph shall be deemed to include, subject to the limitations set forth above, any legal or other expenses incurred by such Indemnified Person in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 8, in no event shall the Underwriters be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that the Underwriters have otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The obligation of the Underwriters to contribute pursuant to this Section 8 is several in proportion to their respective underwriting commitment and is not joint.

          The indemnity and contribution agreements contained in this Section 8 are in addition to any liability which the Indemnifying Persons may otherwise have to the Indemnified Persons referred to above.

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          The indemnity and contribution agreements of the parties contained in this Section 8 and the representations, warranties, and covenants of the Company set forth in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of the Underwriters or any person controlling the Underwriters or by or on behalf of the Company, the officers or directors or any other person controlling the Company and (iii) acceptance of and payment for any of the Securities.

          9. Notwithstanding anything herein contained, this Agreement may be terminated in the absolute discretion of the Representative, by notice given to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on or by, as the case may be, the New York Stock Exchange, (ii) trading of any securities of or guaranteed by the Company or the Trust shall have been suspended or materially limited on any exchange or in any over-the-counter market, (iii) a general moratorium on commercial banking activities in New York shall have been declared by either Federal or New York State authorities, (iv) there shall have occurred any outbreak or escalation of hostilities involving the United States or any change in financial markets in the United States or any calamity or crisis or any change or development involving a prospective change in national or international political, financial or economic conditions, in each case the effect of which is such as to make it, in the judgment of the Representative, material and adverse and which, in the judgment of the Representatives makes it impracticable or inadvisable to market the Securities on the terms and in the manner contemplated in the Time of Sale Information and the Prospectus, (v) there has occurred a material disruption in securities settlement or clearance services or (vi) the representation in Section 4(e) is incorrect in any respect.

          10. If this Agreement shall be terminated by the Underwriters because of any failure or refusal on the part of the Company or the Trust to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason the Company or the Trust shall be unable to perform its obligations under this Agreement or any condition of the Underwriters’ obligations cannot be fulfilled, the Company agrees to reimburse the Underwriters, for all out-of-pocket expenses (including the fees and expenses of its counsel) reasonably incurred by the Underwriters in connection with this Agreement or the offering of Securities contemplated hereunder and the Company shall then be under no further liability to the Underwriters except as provided in Sections 5(o) and 8 of this Agreement.

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          11. (a) If, on the Closing Date or any Option Closing Date, as the case may be, any Underwriter shall default in its obligation to purchase the Securities which it has agreed to purchase hereunder, the Representatives may in their discretion arrange for themselves or another party or other parties to purchase such Securities on the terms contained herein. If within thirty six hours after such default by any Underwriter the Representatives do not arrange for the purchase of such Securities, then the Company shall be entitled to a further period of thirty six hours within which to procure another party or other parties reasonably satisfactory to the Representatives to purchase such Securities on such terms. In the event that, within the respective prescribed period, the Representatives notify the Company that they have so arranged for the purchase of such Securities, or the Company notify the Representatives that they have so arranged for the purchase of such Securities, the Representatives or the Company shall have the right to postpone the Closing Date or the Option Closing Date, as the case may be, for such Securities for a period of not more than seven days, in order to effect whatever changes may thereby be made necessary in the Registration Statement, the Time of Sale Information or the Prospectus as amended or supplemented, or in any other documents or arrangements, and the Company agrees to file promptly any amendments or supplements to the Registration Statement, the Time of Sale Information or the Prospectus which in the reasonable opinion of the Representatives may thereby be made necessary. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section with like effect as if such person had originally been a party to the this Agreement with respect to such Securities.

               (b) If, after giving effect to any arrangements for the purchase of the Firm Securities or the Additional Securities, as the case may be, of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided in subsection (a) above, the aggregate principal amount of such Firm Securities or Additional Securities, as the case may be, which remains unpurchased does not exceed one eleventh of the aggregate principal amount of the Firm Securities or Additional Securities, as the case may be, then the Company shall have the right to require each non-defaulting Underwriter to purchase the principal amount of the Firm Securities or Additional Securities, as the case may be, which such Underwriter agreed to purchase under this Agreement relating to such Firm Securities or Additional Securities, as the case may be, and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the principal amount of Firm Securities or Additional Securities, as the case may be, which such Underwriter agreed to purchase under this Agreement) of the Firm

31

Securities or Additional Securities of such defaulting Underwriter or Underwriters for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

               (c) If, after giving effect to any arrangements for the purchase of the Firm Securities or Additional Securities, as the case may be, of a defaulting Underwriter or Underwriters by the Representatives and the Company as provided in subsection (a) above, the aggregate principal amount of Firm Securities or Additional Securities, as the case may be, which remains unpurchased exceeds one eleventh of the aggregate principal amount of the Firm Securities or Additional Securities, as the case may be, as referred to in subsection (b) above, or if the Company shall not exercise the right described in subsection (b) above to require non-defaulting Underwriters to purchase the Firm Securities or Additional Securities, as the case may be, of defaulting Underwriter or Underwriters, then this Agreement shall thereupon terminate, without liability on the part of any non-defaulting Underwriter or the Company, and the Company shall then be under no further liability to the Underwriters except as provided in Sections 5(o) and 8 of this Agreement; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

          12. This Agreement shall inure to the benefit of and be binding upon the Company, the Trust, the Underwriters, any controlling persons referred to herein and their respective successors and assigns. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any other person, firm or corporation any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. No purchaser of Securities from the Underwriters shall be deemed to be a successor by reason merely of such purchase.

          13. Under the terms of the Company’s Amended and Restated Declaration of Trust, all persons dealing with the Company shall look solely to the Company property for satisfaction of claims of any nature, and no trustee, officer, agent or shareholder of the Company shall be held to any person liable in tort, contract or otherwise as the result of the execution and delivery of this Agreement by the Company. Under the terms of the Trust’s Amended and Restated Declaration of Trust, all persons dealing with the Trust shall look solely to the Trust property for satisfaction of claims of any nature, and no trustee, officer, agent or shareholder of the Trust shall be held to any person liable in tort, contract or otherwise as the result of the execution and delivery of this Agreement by the Trust.

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          14. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriters shall be given to Citigroup Global Markets Inc., 388 Greenwich Street, New York, New York 10013, Fax: 212-723-5074, Attention: Legal Department and Morgan Stanley & Co. Incorporated, 1585 Broadway, New York, New York 10036, Fax: (212) 507-2932, Attention: Financing Services Group. Notices to the Company and the Trust shall be given to it at 9200 East Panorama, Suite 400, Englewood, Colorado 80112, fax: (303) 708-6954, Attention: Caroline Brower, Executive Vice President and General Counsel.

          15. This Agreement may be signed in counterparts, each of which shall be an original and all of which together shall constitute one and the same instrument. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without giving effect to the conflicts of laws provisions thereof.

          16. The Company and the Trust acknowledges and agrees that the Underwriters are acting solely in the capacity of an arm’s length contractual counterparty to the Company and the Trust with respect to the offering of Securities contemplated hereby (including in connection with determining the terms of the offering) and not as an agent or fiduciary to the Company or any other person. Additionally, the Underwriters are not advising the Company or the Trust or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company and the Trust shall consult with their own advisors concerning such matters and shall be responsible for making its own independent investigation and appraisal of the transactions contemplated hereby, and the Underwriters shall have no responsibility or liability to the Company or the Trust with respect thereto. Any review by the Underwriters of the Company, the Trust, and the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company or the Trust.

[REMAINDER OF THE PAGE INTENTIONALLY LEFT BLANK]

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          If the foregoing is in the accordance with your understanding, please sign and return to us five counterparts hereof.

Very truly yours,
ARCHSTONE–SMITH OPERATING TRUST
By:	/s/ Charles E. Mueller, Jr.
	Name: Charles E. Mueller, Jr.
	Title: Chief Financial Officer
ARCHSTONE–SMITH TRUST
By:	/s/ Charles E. Mueller, Jr.
	Name: Charles E. Mueller, Jr.
	Title: Chief Financial Officer

Accepted: July 11, 2006

CITIGROUP GLOBAL MARKETS INC.

By:	/s/ Paul J. Ingrassia
	Name: Paul J. Ingrassia
	Title: Managing Director
MORGAN STANLEY & CO. INCORPORATED
By:	/s/ Todd J. Singer
	Name: Todd J. Singer
	Title: Executive Director
Acting on behalf of themselves and as the
Representatives of the other Underwriter

Schedule I

Underwriters:	Citigroup Global Markets Inc.	$	200,000,000
	Morgan Stanley & Co. Incorporated	$	200,000,000
	J.P. Morgan Securities Inc.	$	100,000,000
	Total	$	500,000,000

Underwriting Agreement dated:	July 11, 2006
Registration Statement Number:	333-133285
Issuer of Securities	Archstone-Smith Operating Trust (the “Company”)
Issuer of Common Shares	Archstone-Smith Trust, a Maryland real estate investment trust and the sole trustee of Archstone-Smith Operating Trust (the “Trust”)
Title of Securities:	4.00% Exchangeable Senior Notes due 2036 (the “Notes”)
Aggregate Principal Amount:	$500,000,000 principal amount (the “Firm Securities”) (plus up to an additional $75,000,000 principal amount available for purchase by the underwriters, solely to cover overallotments (the “Additional Securities”)
Price to Public:	98.75% of the principal amount, plus accrued interest, from July 14, 2006 to the Closing Date
Purchase Price:	98.00% of the principal amount, plus accrued interest, from July 14, 2006 to the Closing Date
Indenture:	Indenture dated as of February 1, 1994 (the “Base Indenture”), as supplemented by the First Supplemental Indenture, dated as of February 2, 1994 (the “First Supplemental Indenture”), between the Company and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as trustee (the “Trustee”) and the Third Supplemental Indenture, dated as of July 14, 2006, between the Company and the Trustee (the “Third Supplemental Indenture,” and together with the First Supplemental Indenture and the Base Indenture, the “Indenture”).
Maturity:	July 15, 2036
Interest Rate:	4.00%
Interest Payment Dates:	January 15 and July 15, commencing January 15, 2007
Sinking Fund Provisions:	None
Closing Date:	The Closing for the Firm Securities will be held at Time of Delivery: 10:00 a.m. (E.S.T.) on July 14, 2006, with the Notes being delivered through the book-entry facilities of The Depository Trust Company (“DTC”) and made available for checking by DTC and the Trustee at least 24 hours prior to the Closing Date
Closing Location:	Offices of Skadden, Arps, Slate, Meagher & Flom LLP, Four Times Square, New York, NY 10036

III-1

Annex A

Time of Sale Information

• Preliminary Prospectus Supplement, dated as of July 10, 2006.

• Final pricing term sheet substantially in the form of Annex B hereto.

A-1

Annex B

Pricing Term Sheet

Term sheet	Registration Statement No. 333-133285
To prospectus dated July 10, 2006	Filed Pursuant to Rule 433 of the Securities Act of 1933
preliminary prospectus supplement dated July 10, 2006

Free Writing Prospectus Dated July 11, 2006

Archstone-Smith Operating Trust

$500,000,000

4.00% Exchangeable Senior Notes due 2036

Issuer:	Archstone-Smith Operating Trust
Issuer of Common Shares:	Archstone-Smith Trust
Ticker for Common Shares:	ASN
Title of Securities:	4.00% Exchangeable Senior Notes Due 2036
Principal Amount Offered:	$500,000,000
Over-allotment Option:	$ 75,000,000
Principal Amount per Note:	$ 1,000
Issue price:	98.75%
Proceeds Net of Aggregate Underwriting Compensation:	$490 million (excluding option to purchase up to $75 million of additional notes)
Annual Interest Rate:	4.00% per year
Premium:	22.00%

B-1

Reference Price:	$ 52.14
Exchange Price:	$63.6108 per Archstone-Smith Trust common share
Exchange Trigger Price	$ 82.6940
Initial Exchange Rate:	15.7206 Archstone-Smith Trust common shares per $1,000 principal amount of notes
Trustee:	U.S. Bank National Association
Interest Payment Dates:	January 15 and July 15 of each year, beginning January 15, 2007
Maturity Date:	July 15, 2036
Trade Date:	July 11, 2006
Settlement Date:	July 14, 2006
CUSIP:	039584 AC 1
ISIN NUMBER:	US039584AC16
Underwriters:	Citigroup Global Markets Inc.
	Morgan Stanley & Co. Incorporated
	J.P. Morgan Securities Inc.
Adjustment to Shares Delivered upon Exchange upon Fundamental Change	The following table sets forth the share price and the number of additional shares to be received per $1,000 principal amount of notes:

	Effective Price
Effective Date	$52.14		$55.00		$60.00		$65.00		$70.00		$75.00		$85.00
July 14, 2006		3.4585		2.8269		1.9550		1.3141		0.8468		0.5126		0.1188
July 18, 2007		3.4529		2.7997		1.9038		1.2543		0.7892		0.4620		0.0920
July 18, 2008		3.4290		2.7442		1.8167		1.1573		0.6983		0.3860		0.0532
July 18, 2009		3.3796		2.6484		1.6716		1.0009		0.5559		0.2721		0.0100
July 18, 2010		3.3164		2.4923		1.4113		0.7159		0.3093		0.0944		0.0000
July 18, 2011		3.4585		2.4612		0.9461		0.0000		0.0000		0.0000		0.0000

If the share price is between two share price amounts in the table or the effective date is between two effective dates in the table, the number of additional shares will be determined by a straight-line

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interpolation between the number of additional shares set forth for the higher and lower share price amounts and the two dates, as applicable, based on a 365-day year. In addition, if the share price is greater than $85.00 per share (subject to adjustment), the exchange rate will not be adjusted. If the share price is less than $52.14 per share (subject to adjustment), the exchange rate will not be adjusted. Notwithstanding the foregoing, in no event will the total number of Archstone-Smith common shares issuable upon exchange exceed 19.1791 per $1,000 principal amount of notes, subject to adjustments.

The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC web site at www.sec.gov. Alternatively, the issuer, any Underwriter or any dealer participating in the offering will arrange to send to you the prospectus if you request it by calling Citigroup Global Markets Inc. toll-free 1-800-831-9146, or Morgan Stanley & Co. Incorporated toll-free 1-866-718-1649.

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Annex C

Form of Opinion of Mayer, Brown, Rowe & Maw LLP (all initially-capitalized
terms are as defined in the Underwriting Agreement):

(i) Each of the Company and the Trust has been duly organized and is validly existing as a real estate investment trust in good standing under the laws of the State of Maryland, with power and authority (trust or other) to own its properties and conduct its business as described in the Registration Statement, Time of Sale Information and Prospectus as then amended or supplemented;

(ii) Each of the Company and the Trust has been duly qualified for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties, or conducts any business, so as to require such qualification, other than where the failure to be so qualified or in good standing would not have a Material Adverse Effect on the Company, the Trust and their respective subsidiaries, taken as a whole;

(iii) Other than as set forth or contemplated in the Registration Statement, the Time of Sale Information or the Prospectus, to such counsel’s knowledge, there are no legal or governmental proceedings pending or threatened to which the Company, the Trust or any of their respective Subsidiaries is or may be a party or to which any property of the Company, the Trust or their respective Subsidiaries is or may be the subject which, if determined adversely to the Company, the Trust or such Subsidiaries, could individually or in the aggregate reasonably be expected to have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole; to such counsel’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others; and such counsel does not know of any amendment to the Registration Statement, the Time of Sale Information or the Prospectus required to be filed or of any contracts or other documents of a character required to be filed as an exhibit to the Registration

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Statement, the Time of Sale Information or the Prospectus or required to be incorporated by reference into the Prospectus or required to be described in the Registration Statement the Time of Sale Information or the Prospectus which are not filed or incorporated by reference or described as required;

(iv) This Agreement has been duly authorized, executed and delivered by the Company and the Trust and is a valid and binding agreement of the Company and the Trust, enforceable against the Company and the Trust in accordance with its terms, except to the extent that enforcement thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in effect relating to creditors’ rights generally and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and except as rights to indemnity and contribution hereunder may be limited by applicable law;

(v) The Letter Agreement and the Registration Rights Agreement have been duly authorized, executed and delivered by the Company and the Trust and constitute a valid and binding agreement enforceable against the Company and the Trust in accordance with their terms, except to the extent enforcement thereof may be limited by (a) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in effect relating to creditors’ rights generally and (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity), and except as rights to indemnification under the Registration Rights Agreement may be limited by applicable law;

(vi) The Securities have been duly authorized, executed and delivered by the Company and, when duly authenticated in accordance with the terms of the Indenture and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will constitute valid and binding obligations of the Company entitled to the benefits provided by the Indenture and enforceable against the Company in accordance with their terms, except to the extent that enforcement thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in ef-

C-2

fect relating to creditors’ rights generally and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity);

(vii) The Base Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement of the Company enforceable against the Company in accordance with its terms, except to the extent enforcement thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in effect relating to creditors’ rights generally and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity);

(viii) The First Supplemental Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement of the Company enforceable against the Company in accordance with its terms, except to the extent enforcement thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in effect relating to creditors’ rights generally and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity);

(ix) The Third Supplemental Indenture has been duly authorized, executed and delivered by the Company and constitutes a valid and binding agreement enforceable against the Company in accordance with its terms, except to the extent enforcement thereof may be limited by (i) bankruptcy, insolvency, reorganization, moratorium and similar laws now or hereafter in effect relating to creditors’ rights generally and (ii) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity);

(x) The Indenture has been duly qualified under the Trust Indenture Act;

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(xi) The Indenture and the Securities conform in all material respects to the descriptions thereof in the Registration Statement, the Time of Sale Information and the Prospectus;

(xii) The Company’s authorized, issued and outstanding shares of beneficial interest are as set forth or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus; and all of the issued             shares of beneficial interest have been duly and validly authorized and issued, are fully paid and non-assessable;

(xiii) The Trust’s authorized, issued and outstanding shares of beneficial interest are as set forth or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus; and all of the issued             shares of beneficial interest have been duly and validly authorized and issued, are fully paid and non-assessable and none of the outstanding shares of beneficial interest of the Trust was issued in violation of any preemptive rights of any shareholder of the Trust arising under the Maryland REIT Law (as defined therein) or the Amended and Restated Declaration of Trust or Bylaws of the Trust;

(xiv) The reservation for issuance of the Common Shares initially issuable upon exchange of the Securities has been duly and validly authorized, and, the Common Shares, when issued and delivered in accordance with the provisions of the Securities, the Indenture and the Letter Agreement, will be duly and validly issued and fully paid and non-assessable, and will conform in all material respects to the description of the Common Shares incorporated by reference in the Time of Sale Information or the Prospectus;

(xv) Neither the issuance of the Securities nor the issuance of the Common Shares issuable upon exchange of the Securities are subject to any preemptive or similar rights arising under Title 8, or the Amended and Restated Declaration of Trust or the Bylaws of the Company or the Trust;

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(xvi) To the best of such counsel’s knowledge and information, neither the Company, the Trust nor any of their respective Subsidiaries is, nor with the giving of notice or lapse of time or both would be, in violation of or in default under, (i) their respective Amended and Restated Declaration of Trust, By-Laws, partnership agreement or other governing instruments or (ii) any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument known to such counsel to which the Company, the Trust or any of their respective Subsidiaries is a party or by which it or any of them or any of their respective properties is bound, except for violations and defaults (other than violations or defaults with respect to the Amended and Restated Declaration of Trust and Bylaws of the Company or the Trust) which individually and in the aggregate are would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole;

(xvii) The issue and sale of the Securities, the reservation by the Trust of the Common Shares for issuance upon exchange of the Securities and the performance by the Company and the Trust of all of the provisions and its obligations under the Securities, the Indenture, this Agreement, the Letter Agreement, the Registration Rights Agreement and the consummation of the transactions therein contemplated (i) will not conflict with or result in a breach of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other material agreement or instrument known to such counsel to which the Company, the Trust any of their respective Subsidiaries is a party or by which the Company, the Trust any of their respective Subsidiaries is bound or to which any of the property or assets of the Company, the Trust any of their respective Subsidiaries is subject, nor (ii) will any such action result in any violation of the provisions of the Amended and Restated Declaration of Trust or the By-Laws of the Company or the Trust or any applicable law or statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company, the Trust, their respective Subsidiaries or any of their respective properties, such conflict, breach, default or violation would have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole or a material adverse effect on the consummation of the transactions contemplated by the Securities, the Indenture, this Agreement, the Registration Rights Agreement and the Letter Agreement;

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(xviii) No consent, approval, authorization, order, registration or qualification of or with any court or governmental agency or body is required for the issue and sale of the Securities, the issuance of the Common Shares upon the exchange of the Securities, or the consummation of the other transactions contemplated by this Agreement or the Indenture, except such consents, approvals, authorizations, registrations or qualifications as have been obtained under the Securities Act and the Trust Indenture Act and as may be required under state securities or Blue Sky laws in connection with the purchase and distribution of the Securities by the Underwriters, or consents, the failure of which to obtain would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole or a material adverse effect on the consummation of the transactions contemplated by this Agreement, the Indenture, the Registration Rights Agreement or the Letter Agreement or on the validity and enforceability of the Securities and the Indenture;

(xix) The statements (A) under “Description of Debt Securities” and “Description of Notes” in the Time of Sale Information and the Prospectus, (B) incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus from Item 3 of Part 1 of each of the Company’s and the Trust’s Annual Reports on Form 10-K for the year ended December 31, 2005 and (C) contained in the Registration Statement in Item 15 insofar as such statements constitute a summary of the legal matters, documents or proceedings referred to therein, are true and correct in all material respects. Further, the statements under “Certain U.S. Federal Income Tax Considerations” in the Time of Sale Information and Prospectus constitute, in all material respects, a fair and accurate summary of the United States federal income tax consequences of the purchase, ownership and disposition of the Securities to a holder of such Securities;

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(xx) (A) The Company was qualified to be taxed as a real estate investment trust pursuant to Sections 856 through 860 of the Code, for the fiscal year ended December 31, 1996 through the period ending on and including October 29, 2001, (B) the Trust qualified to be taxed as a real estate investment trust pursuant to Sections 856 through 860 of the Code, as amended, for the fiscal years ended December 31, 2001 through December 31, 2005, and its actual and proposed method of operation will enable the Trust to meet the requirements for qualification and taxation as a REIT, (C) the Company was classified as a partnership, and not as an association or partnership taxable as a corporation, for federal income tax purposes, from October 30, 2001, through the date hereof, (D) based on the representation that the Company will continue to satisfy the “90% qualifying income” test under Section 7704 of the Code, the Company will be classified for federal income tax purposes as a partnership, and not as an association or partnership taxable as a corporation; and (E) neither the Company nor the Trust is an open-end investment company, unit investment trust, closed-end investment company or face-amount certificate company that is or is required to be registered under the Investment Company Act;

(xxi) the investments of the Company described in the Registration Statement, the Time of Sale Information and the Prospectus are permitted investments under the Amended and Restated Declaration of Trust of the Company; and the investments of the Trust described in the Registration Statement, the Time of Sale Information and the Prospectus are permitted investments under the Amended and Restated Declaration of Trust of the Trust;

(xxii) the Registration Statement is effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement has been issued under the Securities Act, no notice pursuant to Rule 401(g)(2) of the Act that would prevent its use has been issued and, to the best of such counsel’s knowledge and information, no proceeding for that purpose has been initiated or threatened by the Commission; and

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(xxiii) Such counsel (A) is of the opinion that each document incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus (except for the financial statements, supporting schedules and other financial data included therein or omitted therefrom and except for the Form T-1 as to which such counsel need express no opinion) when filed with the Commission complied as to form in all material respects with the Exchange Act, and (B) is of the opinion that the Registration Statement, the Time of Sale Information and the Prospectus and any amendments and supplements thereto (except for the financial statements, supporting schedules and other financial data included therein or omitted therefrom and except for the Form T-1 as to which such counsel need express no opinion) comply as to form in all material respects with the requirements of the Securities Act and the Trust Indenture Act.

     Such counsel will also indicate that it has examined various documents and records and participated in conferences with the Underwriters, officers and other representatives of the Company and the Trust , representatives of the independent public or certified public accountants for the Company and the Trust and the representatives of the Underwriters at which the contents of the Registration Statement, the Time of Sale Information (which is defined in such opinion to include the Preliminary Prospectus dated July 10, 2006, and each “free writing prospectus” (as defined pursuant to Rule 405 under the Securities Act) listed on Annex A to this Agreement) and the Prospectus, and any supplements or amendments thereto, and related matters were discussed and, although we are not passing upon and do not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Time of Sale Information or the Prospectus, including documents incorporated by reference therein (other than as specified above) or any supplement or amendment thereto, on the basis of the foregoing, no facts have come to our attention that lead us to believe that:

     (i) the Registration Statement or any amendment thereto, at the time such Registration Statement or any such amendment became effective (including the information deemed to be part of the

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Registration Statement at the time it became effective pursuant to Rule 430A, 430B or 430C under the Securities Act) or at the date and time that this Agreement is executed and delivered by the parties hereto, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading;

     (ii) the Prospectus, as of its date or at the Closing Date, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; or

     (iii) the Time of Sale Information as of the date and time that this Agreement is executed and delivered by the parties hereto, contained any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of circumstances under which they were made, not misleading

(it being understood that we express no belief as to the Form T-1 or the financial statements, supporting schedules and other financial or statistical data included or incorporated by reference therein or derived or omitted therefrom).

        In rendering such opinions, such counsel may rely (A) as to matters involving the application of laws other than the laws of the United States and the States of Illinois, Maryland and New York, to the extent such counsel deems proper and to the extent specified in such opinion, if at all, upon an opinion or opinions (in form and substance reasonably satisfactory to Underwriters’ counsel) of other counsel reasonably acceptable to the Underwriters’ counsel, familiar with the applicable laws; and (B) as to matters of fact, to the extent such counsel deems proper, on certificates of responsible officers of the Company and the Trust and certificates or other written statements of officials of jurisdictions having custody of documents respecting the corporate existence or good standing of the Company and the Trust. The opinion of such counsel for the Company and/or the Trust shall state that the opinion of any such other counsel or such certificates is in form satisfactory to such counsel and, in such counsel’s

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opinion, the Underwriters and they are justified in relying thereon. With respect to the matters to be covered in subparagraph (xx) above counsel may state their opinion and belief is based upon their participation in the preparation of the Registration Statement and the Prospectus and any amendment or supplement thereto but is without independent check or verification except as specified. In rendering the opinions contained in (xiii), such opinions may be based upon (a) the Code and the rules and regulations promulgated thereunder, (b) Maryland law existing and applicable to the Company and the Trust, (c) facts and other matters set forth in the Prospectus, (d) the provisions of the Amended and Restated Declaration of Trust of the Company, and (e) certain statements and representations made by the Company and/or the Trust to Mayer, Brown, Rowe & Maw LLP provided that such statements and representations are also set forth in a certificate to the Underwriters.

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Annex D

Form of Opinion of General Counsel (all initially-capitalized terms are as
defined in the Underwriting Agreement):

          (i) other than as set forth or contemplated in the Prospectus, there are no legal or governmental proceedings pending or, to the best of her knowledge, threatened to which the Company, the Trust any of their respective Subsidiaries is or may be a party or to which any property of the Company, the Trust or their respective Subsidiaries is or may be the subject which, if determined adversely to the Company, the Trust or such Subsidiaries, could individually or in the aggregate reasonably be expected to have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries taken as a whole;

          (ii) to the best of her knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others; she does not know of any amendment to the Registration Statement, the time of Sale Information or the Prospectus required to be filed; and there are no contracts or other documents of a character required to be filed as an exhibit to the Registration Statement or required to be incorporated by reference into the Prospectus or required to be described in the Registration Statement, the Time of Sale Information or the Prospectus which are not filed or incorporated by reference or described as required; and

          (iii) neither the Company, the Trust nor any of their respective Subsidiaries is, nor with the giving of notice or lapse of time or both would be, in violation of or in default under, (i) their respective Amended and Restated Declaration of Trust, By-Laws, partnership agreement or other governing instruments or (ii) any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument known to such counsel to which the Company, the Trust or any of their respective Subsidiaries is a party or by which it or any of them or any of their respective properties is bound, except for violations and defaults (other than violations or defaults with respect to the Amended and Restated Declaration of Trust and Bylaws of the Company or the Trust) which individually and in the aggregate are would not have a Material Adverse Effect on the Company, the Trust and their respective Subsidiaries, taken as a whole.

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Annex E

Form of Lock-up Agreement

, 2006

Citigroup Global Markets Inc.
Morgan Stanley & Co. Incorporated
As Representatives of the several Underwriters

c/o Citigroup Global Markets Inc.
388 Greenwich Street
New York, New York 10013

and

Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York 10036

[Trustee or Executive Officer]
c/o Archstone-Smith Trust
9200 E. Panorama Circle, Suite 400
Englewood, CO 80112

Ladies and Gentlemen:

The undersigned understands that Citigroup Global Markets Inc. and Morgan Stanley & Co. Incorporated (the “Representatives”) has entered into an Underwriting Agreement (the “Underwriting Agreement”) with Archstone-Smith Operating Trust, a real estate investment trust organized under the laws of the State of Maryland (the “Operating Trust”) and Archstone-Smith Trust, a real estate investment trust organized under the laws of the State of Maryland (the “Trust”), with respect to the public offering (the “Public Offering”) by the several Underwriters listed therein, including the Representatives (the “Underwriters”) of $500,000,000 aggregate principal amount of exchangeable notes due 2036 of the Operating Trust (the “Notes”), exchangeable into the Trust’s common shares of beneficial interest, par value $0.01 per share (the “Common Shares”) and with respect to the grant by the Operating Trust to the Underwriters of an option to purchase $75,000,000 additional aggregate principal amount of Notes to cover over-

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allotments, if any.

As a condition to the closing of the transactions contemplated by the Underwriting Agreement, the undersigned hereby agrees that, without the prior written consent of the Required Consenting Parties (as defined below), it will not, during the period commencing on the date hereof and ending 60 days after the date of the final prospectus and prospectus supplement relating to the Public Offering (the “Prospectus”), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any Common Shares or any securities convertible into or exercisable or exchangeable for Common Shares, or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Shares, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Shares or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (a) the issuance of any Common Shares to holders of the Securities upon exchange of the Securities, (b) transactions relating to Common Shares or other securities acquired in open market transactions after the completion of the Public Offering, (c) transfers of Common Shares or securities convertible into or exercisable or exchangeable for Common Shares to a family member of the undersigned or trust created for the benefit of the undersigned or a family member of the undersigned, (d) as a bona fide gift or gifts or (e) dispositions of Common shares effected pursuant to a written plan meeting the requirements of Rule 10b5-1 promulgated under the Securities Act of 1933, as amended, provided that such plan was entered into prior to July 11, 2006, provided that in the case of any transfer or distribution pursuant to clause (c) or (d), (i) each transferee agrees to be bound by the terms of this agreement and (ii) no filing by any party (transferee or transferor) under Section 16(a) of the Securities Exchange Act of 1934 shall be required or shall be made voluntarily in connection with such transfer or distribution (other than a filing on Form 5 made after the expiration of the 60-day period referred to above). In addition, the undersigned agrees that, without the prior written consent of the Required Consenting Parties, it will not, during the period commencing on the date hereof and ending 60 days after the date of the Prospectus, make any demand for or exercise any right with respect to, the registration of any Common Shares or any security convertible into or exercisable or exchangeable for Common Shares. The undersigned also agrees and consents to the entry of stop transfer instructions with the Trust’s transfer agent and registrar against the transfer of the undersigned’s Common Shares except in compliance with the foregoing restrictions.

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As used herein, “Required Consenting Party” means both (A) the Representatives and (B) the Trust; provided that in the case of any consent granted by the Trust, such consent shall be evidenced by a resolution of the Board of Trustees of the Trust upon which any trustee requesting consent (in his or her capacity as a shareholder) shall not be entitled to vote.

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Agreement. The undersigned understands that the Company and the Underwriters are relying upon this Lock-Up Agreement in proceeding toward consummation of the Public Offering. The undersigned further understands that this Lock-Up Agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors and assigns.

Very truly yours,

(Signature)

(Name)

(Address)

(Facsimile Number)

(Telephone Number)

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EX-4.1

Exhibit 4.1

ARCHSTONE-SMITH OPERATING TRUST

as Issuer

and

U.S. BANK NATIONAL ASSOCIATION

as Trustee

THIRD SUPPLEMENTAL INDENTURE

Dated as of July 14, 2006

4.00% Exchangeable Senior Notes Due 2036

Table of Contents

		Page
	ARTICLE 1
	Definitions
Section 1.01	Relation to Base Indenture and Supplemental Indentures		2
Section 1.02	Definitions		2
	ARTICLE 2
	Issue, Description, Execution, Registration and Exchange of Notes
Section 2.01	Designation and Amount		8
Section 2.02	Form of Notes		8
Section 2.03	Date and Denomination of Notes; Payments of Interest		9
Section 2.04	Reserved		9
Section 2.05	Execution, Authentication and Delivery of Notes		9
Section 2.06	Exchange and Registration of Transfer of Notes; Restrictions on Transfer; Depositary		10
Section 2.07	Additional Notes; Repurchases		11
Section 2.08	No Sinking Fund		11
Section 2.09	Ranking		11
	ARTICLE 3
	Redemption
Section 3.01	Right to Redeem		12
Section 3.02	Selection of Notes to be Redeemed		12
Section 3.03	Notice of Redemption		12
	ARTICLE 4
	Particular Covenants of the Company
Section 4.01	Payment of Principal and Interest		13
Section 4.02	No Limitation on Incurrence of Debt		13
	ARTICLE 5
	Defaults and Remedies
Section 5.01	Events of Default		14
	ARTICLE 6
	Supplemental Indentures
Section 6.01	Supplemental Indentures Without Consent of Noteholders		14
Section 6.02	Modification and Amendment with Consent of Noteholders		14
Section 6.03	Effect of Supplemental Indentures		15

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		Page
	ARTICLE 7
	Consolidation, Merger, Sale, Conveyance and Lease
Section 7.01	Company May Consolidate, Etc. on Certain Terms		15
	ARTICLE 8
	Exchange of Notes
Section 8.01	Exchange		15
Section 8.02	Exchange Procedures		19
Section 8.03	Reserved		23
Section 8.04	Adjustment of Exchange Rate		23
Section 8.05	Sufficient Shares to be Delivered		30
Section 8.06	Effect of Reclassification, Consolidation, Merger or Sale		30
Section 8.07	Certain Covenants		32
Section 8.08	Responsibility of Trustee		32
Section 8.09	Notice to Holders Prior to Certain Actions		32
Section 8.10	Shareholder Rights Plans		33
Section 8.11	Ownership Limit		33
Section 8.12	Net Share Settlement Election		33
Section 8.13	Registration of Common Shares		33
	ARTICLE 9
	Repurchase of Notes at Option of Holders
Section 9.01	Repurchase of Securities at Option of the Holder on Specified Dates		34
Section 9.02	Repurchase at Option of Holders Upon a Fundamental Change		38
	ARTICLE 10
	Miscellaneous Provisions
Section 10.01	Ratification of Base Indenture		41
Section 10.02	Provisions Binding on Company’s Successors		41
Section 10.03	Official Acts by Successor Corporation		41
Section 10.04	Addresses for Notices, Etc.		41
Section 10.05	Governing Law		42
Section 10.06	Evidence of Compliance with Conditions Precedent; Certificates and Opinions of Counsel to Trustee		42
Section 10.07	Non-Business Day		42
Section 10.08	No Security Interest Created		42
Section 10.09	Benefits of Indenture		42
Section 10.10	Table of Contents, Headings, Etc.		42
Section 10.11	Execution in Counterparts		43
Section 10.12	Trustee		43
Section 10.13	Further Instruments and Acts		43
Section 10.14	Waiver of Jury Trial		43
Section 10.15	Force Majeure		43

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     THIRD SUPPLEMENTAL INDENTURE dated as of July 14, 2006 (the “Third Supplemental Indenture”), by and between ARCHSTONE-SMITH OPERATING TRUST (formerly known Archstone Communities Trust and prior thereto as Security Capital Pacific Trust and Property Trust of America), a real estate investment trust organized under the laws of the State of Maryland having its principal office at 9200 E. Panorama Circle, Suite 400, Englewood, Colorado 80112 (hereinafter sometimes called the “Company”), and U.S. BANK NATIONAL ASSOCIATION (as successor in interest to State Street Bank and Trust Company), a national banking association having a corporate trust office at 100 Wall Street, Suite 1600, New York, New York 10005, as successor trustee under the Base Indenture (as defined below)(the “Trustee”).

W I T N E S S E T H:

     WHEREAS, the Company has heretofore delivered to the Trustee an indenture dated as of February 1, 1994 (the “Base Indenture”) by and between Property Trust of America (as the Company was formerly known) and Morgan Guaranty Trust Company of New York (as predecessor to State Street Bank and Trust Company, which became the successor trustee pursuant to the First Supplemental Indenture, as defined below) providing for the issuance by the Company from time to time of its senior debt securities evidencing its unsecured and unsubordinated indebtedness (the “Securities”); and

     WHEREAS, Section 301 of the Base Indenture provides for various matters with respect to any series of Securities issued under the Base Indenture to be established in an indenture supplemental to the Base Indenture; and

     WHEREAS, Section 901(7) of the Base Indenture provides for the Company and the Trustee to enter into an indenture supplemental to the Base Indenture to establish the form or terms of Securities of any series as provided by Section 201 and Section 301 of the Base Indenture; and

     WHEREAS, the terms of the Base Indenture, other than Section 801, Section 1004, Article 12 and Article 13 thereof, as amended and supplemented by the first supplemental indenture thereto, dated as of February 2, 1994 (the “First Supplemental Indenture”), and except as otherwise provided in this Third Supplemental Indenture, are binding upon the Notes (as defined below) issued pursuant to this Third Supplemental Indenture (together with the Base Indenture and the First Supplemental Indenture, the “Indenture”); and

     WHEREAS, the terms of this Third Supplemental Indenture apply only to the Notes (as defined below), which Notes shall be subject to additional issuances at the discretion of the Company pursuant to Section 2.07; and

     WHEREAS, the second supplemental indenture to the Base Indenture, dated as of August 2, 2004 (the “Second Supplemental Indenture”), does not apply to the Notes (as defined below); and

     WHEREAS, for its lawful corporate purposes, the Company has duly authorized the issuance of its 4.00% Exchangeable Senior Notes Due 2036 (hereinafter referred to as the

“Notes”), initially in an aggregate principal amount not to exceed $575,000,000, and in order to provide the terms and conditions upon which the Notes are to be authenticated, issued and delivered, the Company and the board of trustees of Archstone-Smith Trust, a Maryland real estate investment trust (“Archstone-Smith Trust”), on behalf of Archstone-Smith Trust, including in Archstone-Smith Trust’s capacity as the sole trustee of the Company, have each duly authorized the execution and delivery of this Third Supplemental Indenture; and

     WHEREAS, the Notes (including the certificate of authentication to be borne by the Notes), a form of Put Right Repurchase Notice, a form of Fundamental Change Repurchase Notice, a form of Exchange Notice and a form of assignment and transfer are to be substantially in the forms hereinafter provided for; and

     WHEREAS, all acts and things necessary to make the Notes, when executed by the Company and authenticated and delivered by the Trustee or a duly authorized Authenticating Agent, as in this Indenture provided, the valid, binding and legal obligations of the Company, and to constitute these presents a valid agreement according to its terms, have been done and performed, and the execution of this Third Supplemental Indenture and the issue hereunder of the Notes have in all respects been duly authorized.

     NOW, THEREFORE, THIS THIRD SUPPLEMENTAL INDENTURE WITNESSETH:

     That in order to declare the terms and conditions upon which the Notes are, and are to be, authenticated, issued and delivered, and in consideration of the premises and of the purchase and acceptance of the Notes by the Holders thereof, the Company covenants and agrees with the Trustee for the equal and proportionate benefit of the respective Holders from time to time of the Notes (except as otherwise provided below), as follows:

ARTICLE 1
Definitions

     Section 1.01 Relation to Base Indenture and Supplemental Indentures.

     (a) This Third Supplemental Indenture shall constitute an Integral part of the Base Indenture.

     (b) Section 801, Section 1004, Article 12 and Article 13 of the Base Indenture shall not apply to the Notes, and the Second Supplemental Indenture shall not apply to the Notes;

     Section 1.02 Definitions. For all purposes of this Third Supplemental Indenture, except as otherwise expressly provided for or unless the context otherwise requires:

     (a) Capitalized terms used but not defined herein shall have the respective meanings assigned to them in the Base Indenture;

     (b) Terms defined both herein and in the Base Indenture shall have the meanings assigned to them herein;

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     (c) All references herein to Articles and Sections, unless otherwise specified, refer to the corresponding Articles and Sections of this Third Supplemental Indenture; and

     (d) All other terms used in this Third Supplemental Indenture, which are defined in the Trust Indenture Act or which are by reference therein defined in the Securities Act (except as herein otherwise expressly provided or unless the context otherwise requires) shall have the meanings assigned to such terms in the Trust Indenture Act and in the Securities Act as in force at the date of the execution of this Third Supplemental Indenture. The words “herein,” “hereof,” “hereunder,” and words of similar import refer to this Third Supplemental Indenture as a whole and not to any particular Article, Section or other Subdivision. The terms defined in this Article include the plural as well as the singular.

     “Additional Settlement Consideration” shall have the meaning specified in Section 8.02(k).

     “Additional Shares” shall have the meaning specified in Section 8.01(g).

     “Archstone-Smith Trust” shall have the meaning specified in the Recitals.

     “Base Indenture” shall have the meaning specified in the Recitals.

     “Board of Trustees” means the board of trustees of Archstone-Smith Trust, acting on behalf of Archstone-Smith Trust as the sole trustee of the Company.

     “Close of Business” means 5:00 p.m. (New York City time).

     “Common Shares” means, subject to Section 8.06, the common shares of beneficial interest of Archstone-Smith Trust, par value $0.01 per share, at the date of this Third Supplemental Indenture or shares of any class or classes resulting from any reclassification or reclassifications thereof and that have no preference in respect of dividends or of amounts payable in the event of any voluntary or involuntary liquidation, dissolution or winding up of Archstone-Smith Trust and that are not subject to redemption by Archstone-Smith Trust; provided that if at any time there shall be more than one such resulting class, the shares of each such class then so issuable shall be substantially in the proportion which the total number of shares of such class resulting from all such reclassifications bears to the total number of shares of all such classes resulting from all such reclassifications.

     “Common Units” means the Class A-1 common units of beneficial interest, par value $0.01 per unit, of the Company.

     “Company” shall have the meaning specified in the Preamble, and subject to the provisions of Article 7, shall include its successors and assigns.

     “Company Put Right Notice” shall have the meaning specified in Section 9.01(c).

     “Company Put Right Notice Date” shall have the meaning specified in Section 9.01(c).

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     “Daily Exchange Value” means, for each of the 20 consecutive Trading Days during the Observation Period, one-twentieth (1/20) of the product of (a) the applicable Exchange Rate and (b) the Daily VWAP of the Common Shares (or the Reference Property, if applicable) on such day.

     “Daily Settlement Amount,” for each of the 20 Trading Days during the Observation Period, shall consist of:

     (i) cash in an amount equal to the Specified Percentage, multiplied by the Daily Exchange Value relating to such day or equal to the Specified Amount (or, if the Company makes the Net Share Settlement Election, cash in an amount equal to not less than the lower of $50 and the Daily Exchange Value relating to such day); and

     (ii) a number of Common Shares equal to (x) the difference between such Daily Exchange Value and the Specified Amount (to the extent that the Specified Amount is greater than zero), divided by (y) the Daily VWAP of the Common Shares for such day.

     “Daily VWAP” for each Common Share means, for each of the 20 consecutive Trading Days during the Observation Period, the per share volume-weighted average price as displayed under the heading “Bloomberg VWAP” on Bloomberg page [ASN<equity> AQR] in respect of the period from 9:30 a.m. to 4:00 p.m. (New York City time) on such Trading Day (or if such volume-weighted average price is unavailable, the market value of one Common Share on such Trading Day as the Board of Trustees determines in good faith using a volume-weighted method).

     “Depositary” means, with respect to the Notes issuable or issued in whole or in part in global form, the person specified in the Base Indenture as the Depositary with respect to such Notes, until a successor shall have been appointed and become such pursuant to the applicable provisions of this Indenture, and thereafter, “Depositary” shall mean or include such successor.

     “Distributed Property” shall have the meaning specified in Section 8.04(c).

     “Dividend Threshold Amount” shall have the meaning specified in Section 8.04(d).

     “Effective Date” shall have the meaning specified in Section 8.01(g)(ii).

     “Event of Default” means, with respect to the Notes, any event specified in Section 5.01, continued for the period of time, if any, and after the giving of notice, if any, therein designated.

     “Ex-Dividend Date” means, (a) with respect to Section 8.01(e), the first date upon which a sale of a Common Share does not automatically transfer the right to receive the relevant dividend from the seller of the Common Shares to its buyer, and (b) in all other cases, with respect to any issuance or distribution on the Common Shares or any other equity security, the first date on which the Common Shares or such other equity security trade on the applicable exchange or in the applicable market, regular way, without the right to receive such issuance or distribution.

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     “Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

     “Exchange Agent” shall mean the Trustee or any successor office or agency where the Notes may be surrendered for exchange.

     “Exchange Date” shall have the meaning specified in Section 8.02(c).

     “Exchange Obligation” shall have the meaning specified in Section 8.01(a).

     “Exchange Price” means as of any date $1,000 divided by the Exchange Rate as of such date.

     “Exchange Rate” shall have the meaning specified in Section 8.01(a).

     “Exchange Trigger Price” shall have the meaning specified in Section 8.01(c).

     “First Supplemental Indenture” shall have the meaning specified in the Recitals.

     “Fundamental Change” shall be deemed to occur upon the consummation of any transaction or event (whether by means of an exchange offer, liquidation, tender offer, consolidation, merger, combination, reclassification, recapitalization or otherwise) in connection with which more than 50% of the Common Shares are exchanged for, converted into, acquired for or constitutes solely the right to receive, consideration which is not at least 90% common equity (or American Depositary Shares representing shares of common equity) that is: (a) listed on, or immediately after the consummation of such transaction or event, will be listed on, a United States national securities exchange, or (b) approved, or immediately after such transaction or event will be approved, for quotation on the Nasdaq Global Market or any similar United States system of automated dissemination of quotations of securities prices.

     “Fundamental Change Company Notice” shall have the meaning specified in Section 9.02(b).

     “Fundamental Change Repurchase Date” shall have the meaning specified in Section 9.02(a).

     “Fundamental Change Repurchase Notice” shall have the meaning specified in Section 9.02(a)(i).

     “Fundamental Change Repurchase Price” shall have the meaning specified in Section 9.02(a).

     “Global Note” shall have the meaning specified in Section 2.06(b).

     “Indenture” shall have the meaning specified in the Recitals.

     “Interest Payment Date” means January 15 and July 15 of each year, beginning on January 15, 2007.

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     “Last Reported Sale Price” means, with respect to the Common Shares or any other security for which a Last Reported Sale Price must be determined, on any date, the closing sale price per share of the Common Shares or unit of such other security (or, if no closing sale price is reported, the average of the last bid and last ask prices or, if more than one in either case, the average of the average last bid and the average last ask prices) on such date as reported in composite transactions for the principal U.S. securities exchange on which the Common Shares or such other security is traded or, if the Common Shares or such other security are not listed on a U.S. national or regional securities exchange, as reported by the Nasdaq Global Market. If the Common Shares or such other security are not listed for trading on a United States national or regional securities exchange and not reported by the Nasdaq Global Market on the relevant date, the Last Reported Sale Price shall be the last quoted bid price per Common Share or such other security in the over-the-counter market on the relevant date, as reported by the National Quotation Bureau or similar organization. If the Common Shares or such other security is not so quoted, the Last Reported Sale Price shall be the average of the mid-point of the last bid and ask prices for the Common Shares or such other security on the relevant date from each of at least three nationally recognized independent investment banking firms selected from time to time by the Board of Trustees for that purpose. The Last Reported Sale Price shall be determined without reference to extended or after hours trading.

     “Market Disruption Event” means the occurrence or existence for more than a one-half hour period in the aggregate on any scheduled Trading Day for the Common Shares of any suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the applicable stock exchange or otherwise) in the Common Shares or in any options, contracts or future contracts relating to the Common Shares, and such suspension or limitation occurs or exists at any time before 1:00 p.m. (New York City time) on such day.

     “Maturity Date” means July 15, 2036, unless the Notes are earlier repurchased, exchanged or redeemed.

     “Measurement Period” shall have the meaning specified in Section 8.01(b).

     “Merger Event” shall have the meaning specified in Section 8.06.

     “Net Share Settlement Election” shall have the meaning specified in Section 8.12.

     “Noteholder” or “Holder,” as applied to any Note, or other similar terms, means any person in whose name at the time a particular Note is registered on the Security Register.

     “Notice of Exchange” shall have the meaning specified in Section 8.02(c).

     “Observation Period” means the 20 consecutive Trading Day period beginning on and including the second Trading Day after the related Exchange Date in respect of such Note.

     “Predecessor Note” of any particular Note means every previous Note evidencing all or a portion of the same debt as that evidenced by such particular Note; and, for the purposes of this definition, any Note authenticated and delivered under Section 306 of the Base Indenture in lieu of a lost, destroyed or stolen Note shall be deemed to evidence the same debt as the lost, destroyed or stolen Note that it replaces.

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     “Put Right Repurchase Date” shall have the meaning assigned to it in Section 9.01(b).

     “Put Right Repurchase Notice” shall have the meaning assigned to it in Section 9.01(b)(i).

     “Put Right Repurchase Price” shall have the meaning assigned to it in Section 9.01(b).

     “Record Date,” with respect to the payment of interest on any Interest Payment Date, shall have the meaning specified in Section 2.03, and with respect to Section 8.04, shall have the meaning specified in Section 8.04(f).

     “Redemption Price” shall have the meaning specified in Section 3.01(c).

     “Reference Property” shall have the meaning specified in Section 8.06(b).

     “Second Supplemental Indenture” shall have the meaning specified in the Recitals.

     “Securities” shall have the meaning specified in the Recitals.

     “Securities Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

     “Specified Amount” and “Specified Percentage” mean the aggregate principal amount of Notes, or percentage thereof, respectively, for which the Company elects to pay cash pursuant to Section 8.01 and Section 8.12 herein; provided that the Company may provide that the Specified Amount or Specified Percentage for any Trading Day will not be in excess of the Daily Exchange Value.

     “Spin-Off” shall have the meaning specified in Section 8.04(c).

     “Share Price” means the price paid per Common Share in connection with a Fundamental Change pursuant to which Additional Shares shall be added to the Exchange Rate as set forth in Section 8.01(e)(ii), which shall be equal to (i) if Holders of Common Shares receive only cash in such Fundamental Change, the cash amount paid per Common Share and (ii) in all other cases, the average of the Last Reported Sale Prices of the Common Shares over the five consecutive Trading Day period ending on the Trading Day preceding the Effective Date of the Fundamental Change.

     “Third-Party Financial Institution” shall have the meaning specified in Section 8.01(b).

     “Third Supplemental Indenture” shall have the meaning specified in the Preamble.

     “Trading Day” means a day during which (i) trading in Common Shares generally occurs, (ii) there is no Market Disruption Event and (iii) a Last Reported Sale Price for Common Shares (other than a Last Reported Sale Price referred to in the next to last sentence of such definition) is available for such day; provided that if the Common Shares is not admitted for trading or quotation on or by any exchange, bureau or other organization referred to in the definition of Last Reported Sale Price (excluding the next to last sentence of that definition), Trading Date shall mean any Business Day.

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     “Trading Price” with respect to the Notes, on any date of determination, means the average of the secondary market bid quotations obtained by the Trustee for $2.0 million principal amount of Notes at approximately 3:30 p.m., New York City time, on such determination date from three independent nationally recognized securities dealers selected by the Company; provided that if three such bids cannot reasonably be obtained by the Trustee, but two such bids are obtained, then the average of the two bids shall be used, and if only one such bid can reasonably be obtained by the Trustee, that one bid shall be used. If the Trustee cannot reasonably obtain at least one bid for $2.0 million principal amount of Notes from a nationally recognized securities dealer, then the Trading Price per $1,000 principal amount of Notes will be deemed to be less than 98% of the product of the Last Reported Sale Price of the Common Shares and the Exchange Rate.

     “Trigger Event” shall have the meaning specified in Section 8.04(c).

     “Trustee” shall have the meaning specified in the Preamble until a successor trustee shall have become such pursuant to the applicable provisions of the Indenture. The Trustee shall initially serve as the Security Registrar and Paying Agent for the Notes.

     “Trust Indenture Act” refers to the Trust Indenture Act of 1939, as amended, and the rules and regulations promulgated thereunder.

ARTICLE 2
Issue, Description, Execution, Registration and Exchange of Notes

     Section 2.01 Designation and Amount. The Notes shall be designated as the “4.00% Exchangeable Senior Notes Due 2036.” The aggregate principal amount of Notes that may be authenticated and delivered under this Third Supplemental Indenture is initially limited to $575,000,000, subject to Section 2.07 and except for Notes authenticated and delivered upon registration or transfer of, or in exchange for, or in lieu of other Notes pursuant Section 2.06, Section 8.02 and Section 9.02 hereof and Sections 303,304, 305, 306, 906 and 1107 of the Base Indenture.

     Section 2.02 Form of Notes. The Notes and the Trustee’s certificate of authentication to be borne by such Notes shall be substantially in the form set forth in Exhibit A.

     Any of the Notes may have such letters, numbers or other marks of identification and such notations, legends or endorsements as the officers executing the same may approve (execution thereof to be conclusive evidence of such approval) and as are not inconsistent with the provisions of this Indenture, or as may be required to comply with any law or with any rule or regulation made pursuant thereto or with any rule or regulation of any securities exchange or automated quotation system on which the Notes may be listed or designated for issuance, or to conform to usage or to indicate any special limitations or restrictions to which any particular Notes are subject.

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     The Global Note shall represent such principal amount of the Outstanding Notes as shall be specified therein and shall provide that it shall represent the aggregate principal amount of Outstanding Notes from time to time endorsed thereon and that the aggregate principal amount of Outstanding Notes represented thereby may from time to time be increased or reduced to reflect repurchases, exchanges, transfers or exchanges permitted hereby. Any endorsement of the Global Note to reflect the amount of any increase or decrease in the amount of Outstanding Notes represented thereby shall be made by the Trustee or the Custodian, at the direction of the Trustee, in such manner and upon instructions given by the Holder of such Notes in accordance with this Indenture. Payment of principal and accrued and unpaid interest on the Global Note shall be made to the Holder of such Note on the date of payment, unless a Record Date or other means of determining Holders eligible to receive payment is provided for herein.

     The terms and provisions contained in the form of Note attached as Exhibit A hereto are incorporated herein and shall constitute, and are hereby expressly made, a part of this Third Supplemental Indenture and to the extent applicable, the Company and the Trustee, by their execution and delivery of this Third Supplemental Indenture, expressly agree to such terms and provisions and to be bound thereby.

     Section 2.03 Date and Denomination of Notes; Payments of Interest. The Notes shall be issuable in registered form without coupons in denominations of $1,000 principal amount and integral multiples thereof. Each Note shall be dated the date of its authentication and shall bear interest from the date specified on the face of the form of Note attached as Exhibit A hereto. Interest on the Notes shall be computed on the basis of a 360-day year comprised of twelve 30-day months.

     The Person in whose name any Note (or its Predecessor Note) is registered on the Security Register at the Close of Business on any Record Date with respect to any Interest Payment Date shall be entitled to receive the interest payable on such Interest Payment Date. Interest shall be payable at the office of the Company maintained by the Company for such purposes, which shall initially be an office or agency of the Trustee. The Company shall pay interest (i) on any Notes in certificated form by check mailed to the address of the Person entitled thereto as it appears in the Security Register (or upon written application by such Person to the Security Registrar not later than the relevant record date, by wire transfer in immediately available funds to such Person’s account within the United States, if such Person is entitled to interest on an aggregate principal amount in excess of $1,000,000) or (ii) on any Global Note by wire transfer of immediately available funds to the account of the Depositary or its nominee. The term “Record Date” with respect to any Interest Payment Date shall mean the January 1 or July 1 preceding the applicable January 15 or July 15 Interest Payment Date, respectively.

     Section 2.04 Reserved.Execution, Authentication and Delivery of Notes. The Notes shall be signed in the name and on behalf of the Company by the manual or facsimile signature of its Chairman or Vice-Chairman of the Board of Trustees, Chief Executive Officer, President, any of its Executive or Senior Vice Presidents, Managing Director, or any of its Vice Presidents (whether or not designated by a number or numbers or word or words added before or after the title “Vice President”).

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     At any time and from time to time after the execution and delivery of this Third Supplemental Indenture, the Company may deliver Notes executed by the Company to the Trustee for authentication, together with a Company Order for the authentication and delivery of such Notes, and the Trustee in accordance with such Company Order shall authenticate and deliver such Notes, without any further action by the Company hereunder.

     Only such Notes as shall bear thereon a certificate of authentication substantially in the form set forth on the form of Note attached as Exhibit A hereto, manually executed by the Trustee (or an Authenticating Agent appointed by the Trustee as provided by Section 611 of the Base Indenture), shall be entitled to the benefits of this Third Supplemental Indenture or be valid or obligatory for any purpose. Such certificate by the Trustee (or such an Authenticating Agent) upon any Note executed by the Company shall be conclusive evidence that the Note so authenticated has been duly authenticated and delivered hereunder and that the Holder is entitled to the benefits of this Third Supplemental Indenture.

     In case any officer of the Company who shall have signed any of the Notes shall cease to be such officer before the Notes so signed shall have been authenticated and delivered by the Trustee, or disposed of by the Company, such Notes nevertheless may be authenticated and delivered or disposed of as though the person who signed such Notes had not ceased to be such officer of the Company; and any Note may be signed on behalf of the Company by such persons as, at the actual date of the execution of such Note, shall be the proper officers of the Company, although at the date of the execution of this Third Supplemental Indenture any such person was not such an officer.

     Section 2.06 Exchange and Registration of Transfer of Notes; Restrictions on Transfer; Depositary.

     (a) The Company shall provide for the registration of transfers or exchange of the Notes in the Security Register. Upon surrender for registration of transfer of any Note to the Security Registrar or any co-registrar, and satisfaction of the requirements for such transfer set forth in this Section 2.06, the Company shall execute, and the Trustee shall authenticate and deliver, in the name of the designated transferee or transferees, one or more new Notes of any authorized denominations and of a like aggregate principal amount and bearing such restrictive legends as may be required by this Third Supplemental Indenture (if any).

     Notes may be exchanged for other Notes of any authorized denominations and of a like aggregate principal amount, upon surrender of the Notes to be exchanged at any such office or agency maintained by the Company pursuant to Section 4.02. Whenever any Notes are so surrendered for exchange, the Company shall execute, and the Trustee shall authenticate and deliver, the Notes which the Noteholder making the exchange is entitled to receive, bearing registration numbers not contemporaneously outstanding.

     All Notes presented or surrendered for registration of transfer or for exchange, repurchase or exchange shall (if so required by the Company, the Trustee, the Security Registrar or any co-registrar) be duly endorsed, or be accompanied by a written instrument or instruments of transfer in form satisfactory to the Company and duly executed, by the Noteholder thereof or his attorney-in-fact duly authorized in writing.

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     No service charge shall be charged to the Noteholder for any exchange or registration of transfer of Notes, but the Company or the Trustee may require payment of a sum sufficient to cover any tax, assessments or other governmental charges that may be imposed in connection therewith.

     None of the Company, the Trustee, the Security Registrar or any co-registrar shall be required to exchange or register a transfer of (a) any Notes surrendered for exchange or, if a portion of any Note is surrendered for exchange, such portion thereof surrendered for exchange or (b) any Notes, or a portion of any Note, surrendered for repurchase (and not withdrawn), in accordance with Article 9 hereof.

     All Notes issued upon any registration of transfer or exchange of Notes in accordance with this Third Supplemental Indenture shall be the valid obligations of the Company, evidencing the same debt, and entitled to the same benefits under this Indenture as the Notes surrendered upon such registration of transfer or exchange.

     (b) So long as the Notes are eligible for book-entry settlement with the Depositary, unless otherwise required by law, all Notes shall be represented by one or more Notes in global form (each, a “Global Note”) registered in the name of the Depositary or the nominee of the Depositary. The transfer and exchange of beneficial interests in a Global Note, which does not involve the issuance of a definitive Note, shall be effected through the Depositary (but not the Trustee or the Custodian) in accordance with this Indenture (including the restrictions on transfer set forth herein) and the procedures of the Depositary therefor.

     Section 2.07 Additional Notes; Repurchases. The Company may, without the consent of the Noteholders and notwithstanding Section 2.01, reopen the Notes and issue additional Notes hereunder with the same terms and with the same CUSIP number as the Notes initially issued hereunder in an unlimited aggregate principal amount, which will form the same series with the Notes initially issued hereunder, provided that no such additional Notes may be issued unless fungible with the Notes initially issued hereunder for U.S. federal income tax purposes. The Company may also from time to time repurchase the Notes in open market purchases or negotiated transactions without prior notice to Noteholders.

     Section 2.08 No Sinking Fund. The provisions of Article Twelve of the Base Indenture shall not be applicable to the Notes. No sinking fund is provided for the Notes.

     Section 2.09 Ranking. The Notes constitute a senior unsecured general obligation of the Company, ranking equally with other existing and future senior unsecured and unsubordinated indebtedness of the Company and ranking senior in right of payment to any future indebtedness of the Company that is expressly made subordinate to the Notes by the terms of such indebtedness.

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ARTICLE 3
Redemption

     Section 3.01 Right to Redeem.

     (a) Notwithstanding any provision of the Base Indenture, as modified by this Third Supplemental Indenture, to the contrary, the Company may redeem the Notes at any time, in whole but not in part, in order to preserve the status of Archstone-Smith Trust as a real estate investment trust under the Code.

     (b) The Company, at its option, may redeem the Notes from time to time in whole or in part on or after July 18, 2011 if the Company has made at least 10 semi-annual interest payments (including the interest payments on January 15, 2007, and July 15, 2011) in the full amount required by this Indenture; provided that the Company may not provide notice of a redemption of Notes at the Company’s option that specifies that the Company will settle exchanges of Notes prior to such redemption in cash, Common Shares or a combination thereof unless, at the time of such notice, the Company has available to it sufficient registered Common Shares to satisfy its Exchange Obligation in respect of the Notes to be redeemed.

     (c) Any redemption of Notes shall be at a redemption price equal to 100% of the principal amount of the Notes being redeemed, plus accrued and unpaid interest, if any, to the Redemption Date (the “Redemption Price”); provided, however, that the Company may deduct from such Redemption Price any amount required to be deducted and withheld under applicable law.

     Section 3.02 Selection of Notes to be Redeemed.

     (a) The provisions of Section 1103 of the Base Indenture shall govern the selection of Notes to be redeemed by the Trustee; provided, however, that if less than all of the Notes are to be redeemed, the Trustee shall make the selection from the Notes of that series Outstanding and not previously called for redemption, by lot, or in its discretion, on a pro rata basis.

     (b) If any Note selected for partial redemption is exchanged in part before termination of the exchange right with respect to the portion of the Note so selected, the exchanged portion of such Note shall be deemed to be part of the portion selected for redemption. Notes which have been exchanged subsequent to the Trustee commencing selection of Notes to be redeemed but prior to redemption of such Notes shall be treated by the Trustee as Outstanding for the purpose of such selection.

     Section 3.03 Notice of Redemption. The provisions of Section 1104 of the Base Indenture shall govern notices of redemption of the Notes; provided, however, that in addition to the information specified in Section 1104 of the Base Indenture, notices of redemption of the Notes shall also state:

     (a) the then-current Exchange Price;

     (b) the name and address of the Exchange Agent; and

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     (c) that Holders who wish to exchange Notes must surrender such Notes for exchange no later than the Close of Business on the second Business Day immediately preceding the Redemption Date and must satisfy the other requirements set forth herein.

ARTICLE 4
Particular Covenants of the Company

     Section 4.01 Payment of Principal and Interest. (a) Section 307 and Section 1001 of the Base Indenture shall apply to the Notes; provided, however, that, with respect to any Noteholder with an aggregate principal amount in excess of $1,000,000, at the application of such Holder in writing to the Security Registrar not later than the relevant Record Date, accrued and unpaid interest on such Holder’s Notes shall be paid by wire transfer in immediately available funds to such Holder’s account in the United States supplied by such Holder from time to time to the Trustee and Paying Agent (if different from Trustee); provided further that payment of accrued and unpaid interest made to the Depositary shall be paid by wire transfer in immediately available funds in accordance with such wire transfer instructions and other procedures provided by the Depositary from time to time.

     (a) Except as otherwise provided in this Section 4.01(b), a Holder of any Notes at the Close of Business on a Record Date shall be entitled to receive interest on such Notes on the corresponding Interest Payment Date. A Holder of any Notes as of a Record Date that are exchanged after the Close of Business on such Record Date and prior to the opening of business on the corresponding Interest Payment Date shall be entitled to receive interest on the principal amount of such Notes, notwithstanding the exchange of such Notes prior to such Interest Payment Date. However, a Holder that surrenders any Notes for exchange between the Close of Business on a Record Date and the opening of business on the corresponding Interest Payment Date shall be required to pay the Company an amount equal to the interest payable by the Company with respect to such Notes on such Interest Payment Date at the time such Holder surrenders such Securities for exchange, provided, however, that this sentence shall not apply to a Holder that converts Securities:

     (i) in respect of which the Company has given notice of redemption pursuant to Section 3.03 on a Redemption Date that is after the relevant Record Date and on or prior to the relevant Interest Payment Date; or

     (ii) to the extent of any overdue interest, if any overdue interest exists at the time of exchange with respect to such Notes.

     Accordingly, a Holder that converts Notes under any of the circumstances described in clauses (i) or (ii) above will not be required to pay to the Company an amount equal to the interest payable by the Company with respect to such Notes on the relevant Interest Payment Date.

     Section 4.02 No Limitation on Incurrence of Debt.. The provisions of Section 1004 of the Base Indenture shall not be applicable to the Notes.

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ARTICLE 5
Defaults and Remedies

     Section 5.01 Events of Default. The provisions of Sections 501(3), (5) and (6) of the Base Indenture shall not be applicable to the Notes. As contemplated under Section 501(9) of the Base Indenture, the following events, in addition to the events described in Sections 501(1), (2),(4), (7) and (8) of the Base Indenture, shall be Events of Default with respect to the Notes:

     (a) failure by the Company to comply with its obligation to exchange the Notes into cash, Common Shares or a combination of cash and Common Shares, as applicable, upon exercise of a Holder’s exchange right, and such failure continues for a period of 10 days;

     (b) failure by the Company to issue a Fundamental Change Company Notice in accordance with Section 9.02(b) when due, and such failure continues for a period of two days;

     (c) default by the Company in the payment of an aggregate principal amount exceeding $50,000,000 on any evidence of indebtedness of the Company or any mortgage, indenture or other instrument of the Company under which the indebtedness is issued or by which the indebtedness is secured, such default having occurred after the expiration of any applicable grace period and having resulted in the acceleration of the maturity of the indebtedness, but only if the indebtedness is not discharged or the acceleration is not rescinded or annulled; and

     (d) the entry by a court of competent jurisdiction of one or more judgments, orders or decrees against the Company or any of its Subsidiaries in an aggregate amount, excluding amounts fully covered by insurance, in excess of $50,000,000 and such judgments, orders or decrees remain undischarged, unstayed and unsatisfied in an aggregate amount, excluding amounts fully covered by insurance, in excess of $50,000,000 for a period of 30 consecutive days.

ARTICLE 6
Supplemental Indentures

     Section 6.01 Supplemental Indentures Without Consent of Noteholders. The provisions of Section 901 of the Base Indenture shall be applicable to the Notes.

     Section 6.02 Modification and Amendment with Consent of Noteholders. The provisions of Section 902 of the Base Indenture shall be applicable to the Notes. With the consent of the Holders of not less than a majority in aggregate principal amount of the Notes at the time Outstanding, by Act of said Holders delivered to the Company and the Trustee, the Company, when authorized by or pursuant to a Resolution of the Board of Trustees, and the Trustee may enter into an indenture or indentures supplemental to this Indenture, for the purpose of adding any provisions to or changing in any manner or eliminating any of the provisions of this Indenture, or of modifying in any manner the rights of the Holders of Notes and any related coupons under this Indenture; provided, however, that no such supplemental indenture shall, without the consent of the Holder of each Note affected thereby, modify this Indenture in any manner specified in Section 902 of the Base Indenture or, in addition thereto, either of the following:

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     (a) make any change that adversely affects the exchange rights of any Notes; or

     (b) reduce the Fundamental Change Repurchase Price, Redemption Price or Put Right Repurchase Price of any Note or amend or modify in any manner adverse to the Holders of the Notes the Company’s obligation to make such payments, whether through an amendment or waiver of provisions in the covenants, definitions or otherwise.

     Section 6.03 Effect of Supplemental Indentures. Upon the execution of any supplemental indenture under this Article, this Indenture shall be modified in accordance therewith, and such supplemental indenture shall form a part of this Indenture for all purposes; and every Holder of Notes theretofore or thereafter authenticated and delivered under this Indenture and of any coupon appertaining thereto shall be bound thereby.

ARTICLE 7
Consolidation, Merger, Sale, Conveyance and Lease

     Section 7.01 Company May Consolidate, Etc. on Certain Terms. Section 801 of the Base Indenture shall not be applicable to the Notes and in its place and stead the following provision shall be applicable:

     The Company may consolidate with, or sell, lease or convey all or substantially all of its assets to, or merge with or into any other entity, provided that in any such case, (1) either the Company, Archstone-Smith Trust or another Person controlled by Archstone-Smith Trust shall be the continuing entity, or the successor entity, if other than the Company, formed by or resulting from the transaction shall be an entity organized and existing under the laws of the United States, any State thereof or the District of Columbia and such successor entity shall expressly assume the due and punctual payment of the principal of (and premium or Make-Whole Amount, if any) and interest (including any Additional Amounts, if any) on the Notes, according to their tenor, and the due and punctual performance and observance of all of the covenants and conditions of this Indenture, to be performed by the Company, in a manner satisfactory to the Trustee, executed and delivered to the Trustee by such entity; immediately after giving effect to such transaction and treating any indebtedness which becomes an obligation of the Company or any of its Subsidiaries as a result thereof as having been incurred by the Company or such Subsidiary at the time of such transaction, no Event of Default, and no event which, after notice or the lapse of time, or both, would become an Event of Default, shall have occurred and be continuing; and (3) an Officers’ Certificate and Opinion of Counsel covering such conditions shall have been delivered to the Trustee. Upon such consolidation, merger or transfer, the successor entity shall succeed to and may exercise every right and power of the Company under this Indenture.

ARTICLE 8
Exchange of Notes

     Section 8.01 Exchange.

     (a) Subject to the conditions described in clauses (b) through (f) below and to Section 8.11, and upon compliance with the provisions of this Article 8, a Holder of Notes shall have the right, at such Holder’s option, to exchange all or any portion (if the portion to be exchanged is

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$1,000 principal amount or an integral multiple thereof) of such Notes at any time prior to the Close of Business on the scheduled Trading Day immediately preceding July 18, 2011 at a rate (the “Exchange Rate”) of 15.7206 Common Shares (subject to adjustment by the Company as provided in Section 8.04) per $1,000 principal amount Note (the “Exchange Obligation”) under the circumstances and during the periods set forth below. On and after July 18, 2011, regardless of the conditions described in clause (b) through (f) below, upon compliance with the provisions of this Article 8 and subject to Section 8.11 and 8.12, a Noteholder shall have the right, at such Holder’s option, to exchange all or any portion (if the portion to be exchanged is $1,000 principal amount or an integral multiple thereof) of such Note at any time prior to the Close of Business on the scheduled Trading Day immediately preceding the Maturity Date.

     (b) A Holder of Notes shall have the right, at such Holder’s option, to exchange its Notes prior to July 18, 2011, during the five Business Day period immediately after any ten consecutive Trading Day period (the “Measurement Period”) in which the Trading Price per $1,000 principal amount of Notes for each day of such Measurement Period was less than 98% of the product of the Last Reported Sale Price of the Common Shares on such date and the Exchange Rate on such date, all as determined by the Trustee (except the Trading Price). The Trustee shall have no obligation to determine the Trading Price of the Notes. The Company shall request that a third-party nationally recognized financial institution authorized to do business in the United States of America other than the Trustee (the “Third-Party Financial Institution”), determine the Trading Price of the Notes and provide such determination to both the Company and the Trustee in writing; provided that the Company shall have no obligation to make such request unless a Noteholder or group of Noteholders representing at least $1,000,000 aggregate principal amount of Notes provides the Company with reasonable evidence that the Trading Price per $1,000 principal amount of the Notes would be less than 98% of the product of the Last Reported Sale Price at such time and the then-applicable Exchange Rate, at which time the Company shall instruct the Third-Party Financial Institution to determine the Trading Price of the Notes beginning on the next Trading Day and on each successive Trading Day until the Trading Price per $1,000 principal amount of the Notes is greater than or equal to 98% of the product of the Last Reported Sale Price on such date and the then-applicable Exchange Rate. If the Trading Price condition set forth above has been met, the Company shall so notify the Noteholders. If at any time after the Trading Price condition set forth above has been met, the Trading Price per $1,000 principal amount of Notes is greater than 98% of the product of the Last Reported Sale Price on such date and the then-applicable Exchange Rate, the Company shall so notify the Noteholders.

     (c) A Holder of Notes shall have the right, at such Holder’s option, to exchange Notes during any calendar quarter after the quarter ended September 30, 2006, and only during such calendar quarter, if the Last Reported Sale Price for the Common Shares for at least 20 Trading Days during the period of 30 consecutive Trading Days ending on the last Trading Day of the previous calendar quarter exceeds 130% of the Exchange Price (the “Exchange Trigger Price”) on such last Trading Day, which Exchange Price shall be subject to adjustment in accordance with this Article 8. The Company shall employ a Third-Party Financial Institution to determine at the beginning of each calendar quarter whether the Notes are exchangeable as a result of the price of Common Shares, and such Third-Party Financial Institution shall notify the Company and Trustee of its determination.

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     (d) In the event that the Company has delivered a notice of redemption in accordance with Section 1104 of the Base Indenture and Section 3.03 of this Third Supplemental Indenture to the Holders of Notes, a Holder of Notes may exchange Notes at any time prior to the Close of Business on the second Business Day immediately preceding the corresponding Redemption Date; provided, however, that a Holder who has delivered a Fundamental Change Repurchase Notice with respect to a Note may not exchange such Note until the Holder has withdrawn the Fundamental Change Repurchase Notice in accordance with the terms of the Note and this Third Supplemental Indenture.

     (e) (i) In the event that the Company or Archstone-Smith Trust elects to:

     (A) distribute to all or substantially all Holders of Common Shares rights entitling them to purchase, for a period expiring within 60 days after the Record Date for such distribution, Common Shares at a price less than the Last Reported Sale Price of the Common Shares for the Trading Day immediately preceding the declaration date of such distribution; or

     (B) distribute to all or substantially all Holders of Common Shares, assets or debt securities of the Company or Archstone-Smith Trust or rights to purchase the Company’s or Archstone-Smith Trust’s securities, which distribution has a per share value (as determined by the Board of Trustees) exceeding 15% of the Last Reported Sale Price of the Common Shares on the day immediately preceding the date of declaration of such distribution,

then, in either case, Holders may surrender the Notes for exchange at any time on and after the date that the Company provides notice to Holders referred to in the next sentence until the earlier of the Close of Business on the Business Day immediately preceding the Ex-Dividend Date for such distribution or the date the Company announces that such distribution will not take place. The Company shall notify Holders of any distribution referred to in either clause (A) or clause (B) above and of the resulting exchange right no later than the tenth Business Day prior to the Ex-Dividend Date for such distribution.

     (ii) If the Company is a party to any transaction or event that constitutes a Fundamental Change, a Holder may surrender Notes for exchange at any time from and after the 30th scheduled Trading Day prior to the anticipated Effective Date of such transaction or event until the related Fundamental Change Repurchase Date and, upon such surrender, the Holder shall be entitled to the increase in the Exchange Rate, if any, specified in Section 8.01(g). The Company shall give notice to all record Noteholders and the Trustee no later than 30 scheduled Trading Days prior to the anticipated Effective Date of such transaction and issue a press release of the Fundamental Change no later than 45 scheduled Trading Days prior to the anticipated effective date of the Fundamental Change.

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     (iii) If Archstone-Smith Trust is a party to a consolidation, merger, binding share exchange or sale or conveyance of all or substantially all of its properties and assets, in each case pursuant to which the Common Shares would be converted into cash, securities and/or other property, then the Holders shall have the right to exchange Notes at any time beginning fifteen calendar days prior to the date announced by the Company as the anticipated effective date of the transaction and until and including the date that is fifteen calendar days after the date that is the effective date of such transaction; provided such transaction does not otherwise constitute a Fundamental Change to which the provisions of Section 8.01(e)(ii) shall apply. The Company will notify Holders of Notes at least 20 calendar days prior to the anticipated effective date of such transaction. If the Board of Trustees determines the anticipated effective date of the transaction, such determination shall be conclusive and binding on the Holders.

     (f) The Notes shall be exchangeable at any time beginning on the first Business Day after any 30 consecutive Trading Day period during which Common Shares are not listed on either a U.S. national securities exchange or the Nasdaq Global Market.

(g) (i) If a Noteholder elects to exchange Notes in connection with a Fundamental Change that occurs prior to July 18, 2011, the Exchange Rate applicable to each $1,000 principal amount of Notes so exchanged shall be increased by an additional number of Common Shares (the “Additional Shares”) as described below. Settlement of Notes tendered for exchange to which Additional Shares shall be added to the Exchange Rate as provided in this subsection shall be settled pursuant to Section 8.02 below, as applicable. For purposes of this Section 8.01(g), an exchange shall be deemed to be “in connection with” a Fundamental Change to the extent that the related exchange notice is delivered during the time period beginning on the 30th Trading Day prior to the anticipated Effective Date of such Fundamental Change and ending on the related Fundamental Change Repurchase Date, inclusive (regardless of whether the provisions of clauses (b), (c), (d), (e) or (f) of this Section 8.01 shall apply to such exchange). Such exchange notice shall indicate that the Holder of Notes has elected to exchange Notes in connection with a Fundamental Change; provided, however, that the failure to so indicate shall not in any way affect the Exchange Obligation or the right of such Holder to receive Additional Shares in connection with such exchange.

     (ii) The number of Additional Shares by which the Exchange Rate will be increased shall be determined by reference to the table attached as Schedule A hereto, based on the date on which the Fundamental Change occurs or becomes effective (the “Effective Date”), and the Share Price; provided, that if the Share Price is between two Share Price amounts in the table or the Effective Date is between two Effective Dates in the table, the number of Additional Shares shall be determined by a straight-line interpolation between the number of Additional Shares set forth for the next higher and next lower Share Price amounts and the two nearest Effective Dates, as applicable, based on a 365-day year; provided further that if (1) the Share Price is greater than $85.00 per Common Share (subject to adjustment in the same manner as set forth in Section 8.04), no Additional Shares will be added to the Exchange Rate, and (2) the Share Price is

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less than $52.14 per share (subject to adjustment in the same manner as set forth in Section 8.04), no Additional Shares will be added to the Exchange Rate. Notwithstanding the foregoing, in no event will the total number of Common Shares issuable upon exchange exceed 19.1791 per $1,000 principal amount of Notes (subject to adjustment in the same manner as set forth in Section 8.04).

     (iii) The Share Prices set forth in the first row of the table in Schedule A hereto shall be adjusted as of any date on which the Exchange Rate of the Notes is adjusted. The adjusted Share Prices shall equal the Share Prices applicable immediately prior to such adjustment, multiplied by a fraction, the numerator of which is the Exchange Rate in effect immediately prior to the adjustment giving rise to the Share Price adjustment and the denominator of which is the Exchange Rate as so adjusted. The number of Additional Shares within the table shall be adjusted in the same manner as the Exchange Rate as set forth in Section 8.04 (other than by operation of an adjustment to the Exchange Rate by adding Additional Shares).

     Section 8.02 Exchange Procedures.

     (a) Subject to Section 8.02(b) and Section 8.12, the Company will satisfy the Exchange Obligation with respect to each $1,000 principal amount of Notes validly tendered for exchange in cash, fully paid Common Shares or a combination thereof, as applicable, by delivering, on the third Trading Day immediately following the last day of the related Observation Period, cash, Common Shares or a combination thereof, as applicable, equal to the sum of the Daily Settlement Amounts for each of the 20 Trading Days during the related Observation Period; provided that (i) the Company will deliver cash in lieu of fractional Common Shares as set forth pursuant to clause (k) below; (ii) if the Company elects to settle an exchange of notes only in Common Shares, such settlement will occur as soon as practicable after the Company notifies the Holders of the Notes that it has chosen such method of settlement, but in any event within three Business Days of the relevant Exchange Date; and (iii) the Company will inform exchanging Holders by notice to the Trustee no later than two Trading Days beginning on and including the Exchange Date if the Company elects to pay cash upon exchange of the Notes and will specify in such notice the amount or percentage of Notes for which cash will be paid; provided that the Company may provide that the Specified Amount or Specified Percentage for any Trading Day will not be in excess of the Daily Exchange Value. The Daily Settlement Amounts shall be determined by the Company promptly following the last day of the Observation Period.

     (b) Notwithstanding Section 8.02(a), the Company shall satisfy the Exchange Obligation with respect to each $1,000 principal amount of Notes tendered for exchange to which Additional Shares shall be added to the Exchange Rate as set forth in Section 8.01(g) pursuant to this clause (b).

     (i) If the last day of the applicable Observation Period related to Notes surrendered for exchange is prior to the third Trading Day preceding the Effective Date of the Fundamental Change, the Company will satisfy the related Exchange Obligation with respect to each $1,000 principal amount of Notes tendered for

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exchange as described in Section 8.02(b)(ii) by delivering the amount of cash, Common Shares or a combination thereof, as applicable (based on the Exchange Rate, but without regard to the number of Additional Shares to be added to the Exchange Rate pursuant to Section 8.01(g)) on the third Trading Day immediately following the last day of the applicable Observation Period. As soon as practicable following the Effective Date of the Fundamental Change, the Company will deliver the increase in such amount of cash and Reference Property deliverable in lieu of Common Shares, if any, as if the Exchange Rate had been increased by such number of Additional Shares during the related Observation Period (and based upon the related Daily VWAP prices during such Observation Period). If such increased amount of cash and shares, if any, results in an increase to the amount of cash to be paid to Holders, the Company will pay such increase in cash, and if such increased amount results in an increase to the number of Common Shares, the Company will deliver such increase by delivering Reference Property based on such increased number of shares.

     (ii) If the last day of the applicable Observation Period related to Notes surrendered for exchange is on or following the third scheduled Trading Day preceding the Effective Date of such Fundamental Change, the Company will satisfy the Exchange Obligation with respect to each $1,000 principal amount of Notes tendered for exchange as described in Section 8.01(e)(i) (based on the Exchange Rate as increased by the Additional Shares pursuant to Section 8.01(g) above) on the later to occur of (x) the Effective Date of the Fundamental Change and (y) the third Trading Day immediately following the last day of the applicable Observation Period.

     (c) Before any holder of a Note shall be entitled to exchange the same as set forth above, such holder shall (1) in the case of a Global Note, comply with the procedures of the Depositary in effect at that time and, if required, pay funds equal to interest payable on the next Interest Payment Date to which such holder is not entitled as set forth in Section 8.02(i) and, if required, pay all taxes or duties, if any, and (2) in the case of a Note issued in certificated form, (a) complete and manually sign and deliver an irrevocable written notice to the Exchange Agent in the form on the reverse of such certificated Note (or a facsimile thereof) (a “Notice of Exchange”) at the office of the Exchange Agent and shall state in writing therein the principal amount of Notes to be exchanged and the name or names (with addresses) in which such holder wishes the certificate or certificates for any Common Shares, if any, to be delivered upon settlement of the Exchange Obligation to be registered, (b) surrender such Notes, duly endorsed to the Company or in blank (and accompanied by appropriate endorsement and transfer documents), at the office of the Exchange Agent, (c) if required, pay funds equal to interest payable on the next Interest Payment Date to which such holder is not entitled as set forth in Section 8.02(i), and (d) if required, pay all taxes or duties, if any. A Note shall be deemed to have been exchanged immediately prior to the Close of Business on the date (the “Exchange Date”) that the Holder has complied with the requirements set forth in this Section 8.02(c).

     No Notice of Exchange with respect to any Notes may be tendered by a holder thereof if such holder has also tendered a Put Right Repurchase Notice or a Fundamental Change Repurchase Notice and not validly withdrawn such Put Right Repurchase Notice or Fundamental Change Repurchase Notice in accordance with the applicable provisions of Section 9.01 or 9.02, as the case may be.

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     If more than one Note shall be surrendered for exchange at one time by the same holder, the Exchange Obligation with respect to such Notes, if any, that shall be payable upon exchange shall be computed on the basis of the aggregate principal amount of the Notes (or specified portions thereof to the extent permitted thereby) so surrendered.

     (d) Delivery of the amounts owing in satisfaction of the Exchange Obligation shall be made by the Company in no event later than the date specified in Section 8.02(a), except to the extent specified in Section 8.02(b). The Company shall make such delivery by paying the cash amount owed to the Exchange Agent or to the Holder of the Note surrendered for exchange, or such Holder’s nominee or nominees, and by issuing, or causing to be issued, and delivering to the Exchange Agent or to such Holder, or such Holder’s nominee or nominees, certificates or a book-entry transfer through the Depositary for the number of full Common Shares to which such Holder shall be entitled as part of such Exchange Obligation (together with any cash in lieu of fractional shares).

     (e) In case any Note shall be surrendered to the Trustee for partial exchange (along with, if the Company or the Trustee so requires, due endorsements from such Holder, or written instruments of transfer in form satisfactory to the Company and the Trustee duly executed by the Holder thereof or his attorney-in-fact), the Company shall execute and the Trustee shall authenticate and deliver to or upon the written order of the Holder of the Note so surrendered, without charge to such Holder, a new Note or Notes containing identical terms and conditions to the Outstanding Notes in authorized denominations in an aggregate principal amount equal to the unexchanged portion of the surrendered Note.

     (f) If a Holder submits a Note for exchange, the Company shall pay all documentary, stamp and other duties, if any, which may be imposed by the United States or any political subdivision thereof or taxing authority thereof or therein with respect to the issuance of Common Shares, if any, upon the exchange. However, the Holder shall pay any such tax that is due because the Holder requests any Common Shares to be issued in a name other than the Holder’s name. The Exchange Agent may refuse to deliver the certificates representing the Common Shares being issued in a name other than the Holder’s name until the Trustee receives a sum sufficient to pay any tax which will be due because the shares are to be issued in a name other than the Holder’s name. The Exchange Agent may refuse to deliver the certificates representing the Common Shares being issued in a name other than the holder’s name until the Trustee receives a sum sufficient to pay any tax which will be due because the shares are to be issued in a name other than the holder’s name. Nothing herein shall preclude any tax withholding required by law or regulations.

     (g) Except as provided in Section 8.04, no adjustment shall be made for dividends on any shares issued upon the exchange of any Note as provided in this Article.

     (h) Upon the exchange of an interest in a Global Note, the Trustee, or the Custodian at the direction of the Trustee, shall make a notation on such Global Note as to the reduction in the principal amount represented thereby. The Company shall notify the Trustee in writing of any exchange of Notes effected through any Exchange Agent other than the Trustee.

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     (i) Upon exchange, a Noteholder will not receive any separate cash payment for accrued and unpaid interest, except as set forth below. The Company’s settlement of its Exchange Obligation as described above shall be deemed to satisfy its obligation to pay the principal amount of the Note and accrued and unpaid interest to, but not including, the Exchange Date. As a result, accrued and unpaid interest to, but not including, the Exchange Date shall be deemed to be paid in full rather than cancelled, extinguished or forfeited. Notwithstanding the preceding sentence, if Notes are exchanged after the Close of Business on a Record Date, Holders of such Notes as of the Close of Business on the Record Date will receive the interest payable on such Notes on the corresponding Interest Payment Date notwithstanding the exchange. Notes surrendered for exchange during the period from the Close of Business on any regular Record Date to the opening of business on the corresponding Interest Payment Date must be accompanied by payment of an amount equal to the interest payable on the Notes so exchanged; provided, however, that no such payment need be made (1) if the Company has called the Notes for redemption or (2) to the extent of any overdue interest existing at the time of exchange with respect to such Note. Except as described above, no payment or adjustment will be made for accrued interest on exchanged Notes.

     (j) The Person in whose name the certificate for any Common Shares issued upon exchange is registered shall be treated as a Holder of such Common Shares of record on and after the Exchange Date; provided, however, that no surrender of Notes on any date when the share transfer books of the Company shall be closed shall be effective to constitute the Person or Persons entitled to receive the Common Shares upon such exchange as the record Holder or Holders of such Common Shares on such date, but such surrender shall be effective to constitute the Person or Persons entitled to receive such Common Shares as the record Holder or Holders thereof for all purposes at the Close of Business on the next succeeding day on which such share transfer books are open; such exchange shall be at the Exchange Rate in effect on the date that such Notes shall have been surrendered for exchange, as if the share transfer books of the Company had not been closed. Upon exchange of Notes, such Person shall no longer be a Noteholder.

     (k) Notwithstanding any other provision of the Notes, no Holder of Notes shall be entitled to exchange such Notes for Common Shares if and to the extent that the Company has not received such Common Shares from Archstone-Smith Trust. If the Company is unable to deliver shares to any Holder of Notes as described above, the Company will at the Company’s option either pay cash to such Holder in lieu of the Common Shares otherwise deliverable, or issue to such Holder a number of the Company’s Common Units equal to the shortfall in the number of Common Shares otherwise deliverable, with such Common Units having all the rights and privileges provided in the Company’s declaration of trust as in effect on the date of issuance of such Common Units including the right by, and at Archstone-Smith Trust’ election, to have such units redeemed for cash in an amount equal to the fair market value of an equal number of Common Shares or for an equal number of Common Shares.

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     If the Company elects to deliver (x) Common Shares pursuant to clause (ii)(B) of the definition of “Daily Settlement Amount” and such Common Shares constitute “Restricted Securities” as defined in Rule 144 under the Securities Act or (y) the Company’s Common Units in lieu of Common Shares pursuant to the immediately preceding paragraph, the Company shall issue to the Holder an additional 0.03 Common Shares or 0.03 shares of the Company’s Common Units, as applicable, for each Common Share that would otherwise have been due upon exchange (the “Additional Settlement Consideration”). Any Additional Settlement Consideration shall be delivered at the time of the delivery of the Common Shares that would otherwise have been due upon exchange.

     (l) No fractional Common Shares shall be issued upon exchange of any Note or Notes. If more than one Note shall be surrendered for exchange at one time by the same Holder, the number of full shares that shall be issued upon exchange thereof shall be computed on the basis of the aggregate principal amount of the Notes (or specified portions thereof) so surrendered. Instead of any fractional Common Share that would otherwise be issued upon exchange of any Note or Notes (or specified portions thereof), the Company shall pay a cash adjustment in respect of such fraction (calculated to the nearest one-100th of a share) in an amount equal to the same fraction of the Last Reported Sale Price of the Common Shares on the last day of the applicable Observation Period.

     Section 8.03 Reserved.

     Section 8.04 Adjustment of Exchange Rate. The Exchange Rate shall be adjusted from time to time by the Company as follows:

     (a) In case Archstone-Smith Trust shall issue Common Shares as a dividend or distribution to Holders of the outstanding Common Shares, or shall effect a subdivision into a greater number of Common Shares or combination into a lower number of Common Shares, the Exchange Rate shall be adjusted based on the following formula:

ER’ = ER0	x	OS’
		OS0

where
ER0	=	the Exchange Rate in effect immediately prior to such event;
ER’	=	the Exchange Rate in effect immediately after such event;
OS0	=	the number of Common Shares outstanding immediately prior to such event; and
OS’	=	the number of Common Shares outstanding immediately after such event.

Such adjustment shall become effective immediately after 9:00 a.m., New York City time, on the Business Day following the Record Date fixed for such determination. If any dividend or distribution of the type described in this Section 8.04(a) is declared but not so paid or made, or the outstanding Common Shares are not subdivided or combined, as the case may be, the Exchange Rate shall be immediately readjusted, effective as of the date the Board of Trustees determines not to pay such dividend or distribution, or subdivide or combine the outstanding Common Shares, as the case may be, to the Exchange Rate that would then be in effect if such dividend, distribution, subdivision or combination had not been declared.

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     (b) In case Archstone-Smith Trust shall issue to all or substantially all Holders of its outstanding Common Shares rights, warrants or convertible securities entitling them (for a period expiring within sixty (60) calendar days after the issuance thereof) to subscribe for or purchase Common Shares at a price per share less than the Last Reported Sale Price of the Common Shares on the Business Day immediately preceding the date of announcement of such issuance, the Exchange Rate shall be adjusted based on the following formula:

ER’ = ER0	x	OS0 + X
		OS0 + Y

where
ER0	=	the Exchange Rate in effect immediately prior to such event;
ER’	=	the Exchange Rate in effect immediately after such event;
OS0	=	the number of Common Shares outstanding immediately prior to such event;
X	=	the total number of Common Shares issuable pursuant to such rights, warrants or convertible securities; and
Y	=	the number of Common Shares equal to the aggregate price payable to exercise such rights, warrants or convertible securities divided by the average of the Last Reported Sale Prices of Common Shares over the ten consecutive Trading Day period ending on the Business Day immediately preceding the Record Date (or, if later, the Ex-Dividend Date) for the issuance of such rights, warrants or convertible securities.

Such adjustment shall be successively made whenever any such rights, warrants or convertible securities are issued and shall become effective immediately after 9:00 a.m., New York City time, on the Business Day following the date fixed for such determination. If such rights, warrants or convertible securities are not so exercised prior to their expiration, the Exchange Rate shall again be adjusted to be the Exchange Rate that would then be in effect if such Record Date for such distribution had not been fixed.

     In determining whether any rights, warrants or convertible securities entitle the Holders to subscribe for or purchase Common Shares at less than such Last Reported Sale Price, and in determining the aggregate offering price of such Common Shares, there shall be taken into account any consideration received by Archstone-Smith Trust for such rights, warrants or convertible securities and any amount payable on exercise or exchange thereof, the value of such consideration, if other than cash, to be determined by the Board of Trustees.

     (c) In case Archstone-Smith Trust shall, by dividend or otherwise, distribute to all or substantially all Holders of its Common Shares any class of beneficial interest of Archstone-Smith Trust (other than Common Shares as covered by Section 8.04(a)), evidences of its indebtedness or other assets or property of Archstone-Smith Trust (including securities, but

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excluding dividends, distributions, rights and warrants covered by Section 8.04(a), Section 8.04(b) or Section 8.04(d) and distributions described below in this paragraph (c) with respect to Spin-Offs) (any of such shares of beneficial interest, indebtedness, or other asset or property hereinafter in this Section 8.04(c) called the “Distributed Property”), then, in each such case the Exchange Rate shall be adjusted based on the following formula:

ER’ = ER0	x	SP0
		SP0 — FMV

where
ER0	=	the Exchange Rate in effect immediately prior to such distribution;
ER’	=	the Exchange Rate in effect immediately after such distribution;
SP0	=	the average of the Last Reported Sale Prices of the Common Shares over the ten consecutive Trading Day period ending on the Business Day immediately preceding the Record Date for such distribution (or, if earlier, the Ex-Dividend Date); and
FMV	=	the fair market value (as determined by the Board of Trustees) of the shares of beneficial interest, evidences of indebtedness, assets or property distributed with respect to each outstanding Common Share on the Record Date for such distribution (or, if earlier, the Ex-Dividend Date).

Such adjustment shall become effective immediately prior to 9:00 a.m., New York City time, on the Business Day following the date fixed for the determination of shareholders entitled to receive such distribution; provided that if the then fair market value (as so determined) of the portion of the Distributed Property so distributed applicable to one Common Share is equal to or greater than SP0 as set forth above, in lieu of the foregoing adjustment, adequate provision shall be made so that each Noteholder shall have the right to receive, for each $1,000 principal amount of Notes upon exchange, the amount of Distributed Property such Holder would have received had such Holder owned a number of Common Shares equal to the Exchange Rate on the Record Date. If such dividend or distribution is not so paid or made, the Exchange Rate shall again be adjusted to be the Exchange Rate that would then be in effect if such dividend or distribution had not been declared. If the Board of Trustees determines the fair market value of any distribution for purposes of this Section 8.04(c) by reference to the actual or when issued trading market for any securities, it must in doing so consider the prices in such market over the same period used in determining SP0 above.

     With respect to an adjustment pursuant to this Section 8.04(c) where there has been a payment of a dividend or other distribution on the Common Shares of or other beneficial interests in Archstone-Smith Trust, or on any class or series of stock of or similar beneficial interest in or relating to a Subsidiary or other business unit thereof (a “Spin-Off”), the Exchange Rate in effect immediately before 5:00 p.m., New York City time, on the Record Date fixed for determination of shareholders entitled to receive the distribution will be increased based on the following formula:

ER’ = ER0	x	FMV0 + MP0
		MP0

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where
ER0	=	the Exchange Rate in effect immediately prior to such distribution;
ER’	=	the Exchange Rate in effect immediately after such distribution;
FMV0	=	the average of the Last Reported Sale Prices of the beneficial interests distributed to Holders of Common Shares applicable to one Common Share over the first ten consecutive Trading Day period after the effective date of the Spin-Off; and
MP0	=	the average of the Last Reported Sale Prices of Common Shares over the first ten consecutive Trading Day period after the effective date of the Spin-Off.

Such adjustment shall occur on the tenth Trading Day from, and including, the effective date of the Spin-Off; provided that in respect of any exchange within the ten Trading Days following any Spin-Off, references within this paragraph (c) to ten days shall be deemed replaced with such lower number of Trading Days as have elapsed between such Spin-Off and the Exchange Date in determining the applicable Exchange Rate.

     Rights or warrants distributed by Archstone-Smith Trust to all Holders of Common Shares, entitling the Holders thereof to subscribe for or purchase shares of Archstone-Smith Trust’s beneficial interests, including Common Shares (either initially or under certain circumstances), which rights or warrants, until the occurrence of a specified event or events (“Trigger Event”): (i) are deemed to be transferred with such Common Shares; (ii) are not exercisable; and (iii) are also issued in respect of future issuances of Common Shares, shall be deemed not to have been distributed for purposes of this Section 8.04 (and no adjustment to the Exchange Rate under this Section 8.04 will be required) until the occurrence of the earliest Trigger Event, whereupon such rights and warrants shall be deemed to have been distributed and an appropriate adjustment (if any is required) to the Exchange Rate shall be made under this Section 8.04(c). If any such right or warrant, including any such existing rights or warrants distributed prior to the date of this Third Supplemental Indenture, are subject to events, upon the occurrence of which such rights or warrants become exercisable to purchase different securities, evidences of indebtedness or other assets, then the date of the occurrence of any and each such event shall be deemed to be the date of distribution and Record Date with respect to new rights or warrants with such rights (and a termination or expiration of the existing rights or warrants without exercise by any of the Holders thereof). In addition, in the event of any distribution (or deemed distribution) of rights or warrants, or any Trigger Event or other event (of the type described in the preceding sentence) with respect thereto that was counted for purposes of calculating a distribution amount for which an adjustment to the Exchange Rate under this Section 8.04 was made, (1) in the case of any such rights or warrants that shall all have been redeemed or repurchased without exercise by any Holders thereof, the Exchange Rate shall be readjusted upon such final redemption or repurchase to give effect to such distribution or Trigger Event, as the case may be, as though it were a cash distribution, equal to the per share redemption or repurchase price received by a Holder or Holders of Common Shares with respect to such rights or warrants (assuming such Holder had retained such rights or warrants), made to

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all Holders of Common Shares as of the date of such redemption or repurchase, and (2) in the case of such rights or warrants that shall have expired or been terminated without exercise by any Holders thereof, the Exchange Rate shall be readjusted as if such rights and warrants had not been issued.

     For purposes of this Section 8.04(c), Section 8.04(a) and Section 8.04(b), any dividend or distribution to which this Section 8.04(c) is applicable that also includes Common Shares to which Section 8.04(a) applies or rights or warrants to subscribe for or purchase Common Shares to which Section 8.04(b) applies (or both), shall be deemed instead to be (1) a dividend or distribution of the evidences of indebtedness, assets or shares of beneficial interests other than such Common Shares or rights or warrants to which Section 8.04(c) applies (and any Exchange Rate adjustment required by this Section 8.04(c) with respect to such dividend or distribution shall then be made) immediately followed by (2) a dividend or distribution of such Common Shares or such rights or warrants (and any further Exchange Rate adjustment required by Section 8.04(a) and Section 8.04(b) with respect to such dividend or distribution shall then be made), except (A) the Record Date of such dividend or distribution shall be substituted as “the Record Date” and “the date fixed for such determination” within the meaning of Section 8.04(a) and Section 8.04(b) and (B) any Common Shares included in such dividend or distribution shall not be deemed “outstanding immediately prior to such event” within the meaning of Section 8.04(a).

     (d) In case Archstone-Smith Trust shall pay a dividend or make a distribution consisting exclusively of cash to all or substantially all Holders of its Common Shares to the extent that the aggregate of all such cash dividends or distributions paid in any quarter exceeds the Dividend Threshold Amount for such quarter, the Exchange Rate shall be adjusted based on the following formula:

ER’ = ER0	x	SP0 — T
		SP0 — C

where
ER0	=	the Exchange Rate in effect immediately prior to the Record Date for such distribution;
ER’	=	the Exchange Rate in effect immediately after the Record Date for such distribution;
SP0	=	the average of the Last Reported Sale Prices of the Common Shares over the period of ten consecutive Trading Days ending the Business Day immediately preceding the Record Date (as defined in clause (f) of this Section) for such distribution (or, if earlier, the Ex-Dividend date relating to such distribution); and
T	=	the dividend threshold amount (“Dividend Threshold Amount”), which amount shall initially be $0.435 per quarter and which shall be appropriately adjusted from time to time for any share dividends on, or subdivisions or combinations of, Common Shares; provided, that if an Exchange Rate adjustment is required to be made as a result of a distribution that is not a quarterly dividend either in whole or in part, the Dividend Threshold Amount shall be deemed to be zero; and

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C = the amount in cash per share that Archstone-Smith Trust distributes to Holders of Common Shares.

Such adjustment shall become effective immediately after 5:00 p.m., New York City time, on the Record Date for such dividend or distribution; provided that if the portion of the cash so distributed applicable to one Common Share is equal to or greater than SP0 above, in lieu of the foregoing adjustment, adequate provision shall be made so that each Noteholder shall have the right to receive upon exchange of a Note (or any portion thereof) the amount of cash such Holder would have received had such Holder owned a number of shares equal to the Exchange Rate on the Record Date. If such dividend or distribution is not so paid or made, the Exchange Rate shall again be adjusted to be the Exchange Rate that would then be in effect if such dividend or distribution had not been declared.

     For the avoidance of doubt, for purposes of this Section 8.04(d), in the event of any reclassification of the Common Shares, as a result of which the Notes become exchangeable into more than one class of Common Shares, if an adjustment to the Exchange Rate is required pursuant to this Section 8.04(d), references in this Section to one Common Share or Last Reported Sale Price of one Common Share shall be deemed to refer to a unit or to the price of a unit consisting of the number of shares of each class of Common Shares into which the Notes are then exchangeable equal to the number of shares of such class issued in respect of one Common Share in such reclassification. The above provisions of this paragraph shall similarly apply to successive reclassifications.

     (e) In case Archstone-Smith Trust or any of its Subsidiaries makes a payment in respect of a tender offer or exchange offer for all or any portion of the Common Shares, to the extent that the cash and value of any other consideration included in the payment per Common Share exceeds the Last Reported Sale Price of the Common Shares on the Trading Day next succeeding the last date on which tenders or exchanges may be made pursuant to such tender or exchange offer (as it may be amended), the Exchange Rate shall be increased based on the following formula:

ER’ = ER0	x	AC + (SP’ x OS’)
		SP’ x OS0

where
ER0	=	the Exchange Rate in effect on the date such tender or exchange offer expires;
ER’	=	the Exchange Rate in effect on the day next succeeding the date such tender or exchange offer expires;
AC	=	the aggregate value of all cash and any other consideration (as determined by the Board of Trustees) paid or payable for shares purchased in such tender or exchange offer;
OS0	=	the number of Common Shares outstanding immediately prior to the date such tender or exchange offer expires;

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OS’	=	the number of Common Shares outstanding immediately after the date such tender or exchange offer expires; and
SP’	=	the average of the Last Reported Sale Prices of Common Shares over the ten consecutive Trading Day period commencing on the Trading Day next succeeding the date such tender or exchange offer expires,

such adjustment to become effective immediately prior to the opening of business on the day following the last date on which tenders or exchanges may be made pursuant to such tender or exchange offer. If the Company is obligated to purchase shares pursuant to any such tender or exchange offer, but the Company is permanently prevented by applicable law from effecting all or any such purchases or all or any portion of such purchases are rescinded, the Exchange Rate shall again be adjusted to be the Exchange Rate that would then be in effect if such tender or exchange offer had not been made or had only been made in respect of the purchases that had been effected. No adjustment to the Exchange Rate will be made if the application of the foregoing formula would result in a decrease in the Exchange Rate.

     (f) For purposes of this Section 8.04 the term “Record Date” shall mean, with respect to any dividend, distribution or other transaction or event in which the Holders of Common Shares have the right to receive any cash, securities or other property or in which the Common Shares (or other applicable security) is exchanged for or exchanged into any combination of cash, securities or other property, the date fixed for determination of shareholders entitled to receive such cash, securities or other property (whether such date is fixed by the Board of Trustees or by statute, contract or otherwise).

     (g) In addition to those required by clauses (a), (b), (c), (d), and (e) of this Section 8.04, and to the extent permitted by applicable law and subject to the applicable rules of the New York Stock Exchange, the Company from time to time may increase the Exchange Rate by any amount for a period of at least 20 days if the Board of Trustees determines that such increase would be in the Company’s best interest. In addition, the Company may also (but is not required to) increase the Exchange Rate to avoid or diminish any income tax to Holders of Common Shares or rights to purchase Common Shares in connection with any dividend or distribution of shares (or rights to acquire shares) or similar event. Whenever the Exchange Rate is increased pursuant to the preceding sentence, the Company shall mail to the Holder of each Note at his last address appearing on the Security Register provided for in Section 2.06 a notice of the increase at least five days prior to the date the increased Exchange Rate takes effect, and such notice shall state the increased Exchange Rate and the period during which it will be in effect.

     (h) All calculations and other determinations under this Article 8 shall be made by the Company and shall be made to the nearest cent or to the nearest one-ten thousandth (1/10,000) of a share, as the case may be. No adjustment shall be made for Archstone-Smith Trust’s issuance of Common Shares or any securities convertible into or exchangeable for Common Shares, or the right to purchase Common Shares or such convertible or exchangeable securities, other than as provided in this Section 8.04. No adjustment shall be made to the Exchange Rate unless such adjustment would require a change of at least 1% in the Exchange

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Rate then in effect at such time. The Company shall carry forward any adjustments that are less than 1% of the Exchange Rate and make such carried forward adjustments, regardless of whether the aggregate adjustment is less than 1% within one year of the first such adjustment carried forward, upon a Fundamental Change, upon any call of the Notes for redemption or upon maturity.

     (i) Whenever the Exchange Rate is adjusted as herein provided, the Company shall promptly file with the Trustee and any Exchange Agent other than the Trustee an Officers’ Certificate setting forth the Exchange Rate after such adjustment and setting forth a brief statement of the facts requiring such adjustment. The Trustee and Exchange Agent may conclusively rely on the accuracy of the Exchange Rate adjustment provided by the Company. Unless and until a Responsible Officer of the Trustee shall have received such Officers’ Certificate, the Trustee shall not be deemed to have knowledge of any adjustment of the Exchange Rate and may assume without inquiry that the last Exchange Rate of which it has knowledge is still in effect. Promptly after delivery of such certificate, the Company shall prepare a notice of such adjustment of the Exchange Rate setting forth the adjusted Exchange Rate and the date on which each adjustment becomes effective and shall mail such notice of such adjustment of the Exchange Rate to the Holder of each Note at his last address appearing on the Security Register provided for in Section 2.06 of this Third Supplemental Indenture, within thirty (30) days of the effective date of such adjustment. Failure to deliver such notice shall not affect the legality or validity of any such adjustment.

     (j) For purposes of this Section 8.04, the number of Common Shares at any time outstanding shall not include shares held in the treasury of Archstone-Smith Trust but shall include shares issuable in respect of scrip certificates issued in lieu of fractions of Common Shares.

     Section 8.05 Sufficient Shares to be Delivered. To the extent the Company elects to deliver Common Shares, and subject to Section 8.02(k) and Section 8.12, the Company shall provide, free from preemptive rights, sufficient Common Shares to provide for exchange of the Notes from time to time as such Notes are presented for exchange.

     Section 8.06 Effect of Reclassification, Consolidation, Merger or Sale. If any of the following events occur, namely (i) any reclassification or change of the outstanding Common Shares (other than a change in par value, or from par value to no par value, or from no par value to par value, or as a result of a split, subdivision or combination), (ii) any consolidation, merger or combination of Archstone-Smith Trust with another Person, or (iii) any sale or conveyance of all or substantially all of the property and assets of Archstone-Smith Trust to any other Person, in either case as a result of which Holders of Common Shares shall be entitled to receive cash, securities or other property or assets with respect to or in exchange for such Common Shares (any such event a “Merger Event”), then:

     (a) the Company shall execute with the Trustee a supplemental indenture (which shall comply with the Trust Indenture Act as in force at the date of execution of such supplemental indenture if such supplemental indenture is then required to so comply) providing for the exchange and settlement of the Notes as set forth in this Third Supplemental Indenture. Such supplemental indenture shall provide for adjustments which shall be as nearly equivalent as may be practicable to the adjustments provided for in this Article and the Trustee may conclusively rely on the determination by the Company of the equivalency of such adjustments.

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If, in the case of any Merger Event, the Reference Property includes shares of stock or other securities and assets of a corporation other than the successor or purchasing corporation, as the case may be, in such reclassification, change, consolidation, merger, combination, sale or conveyance, then such supplemental indenture shall also be executed by such other corporation and shall contain such additional provisions to protect the interests of the Holders of the Notes as the Board of Trustees shall reasonably consider necessary by reason of the foregoing, including to the extent required by the Board of Trustees and practicable the provisions providing for the repurchase rights set forth in Article 9 herein.

In the event the Company shall execute a supplemental indenture pursuant to this Section 8.06, the Company shall file with the Trustee an Officers’ Certificate briefly stating the kind or amount of cash, securities or property or asset that will constitute the Reference Property after any such Merger Event, any adjustment to be made with respect thereto, and the Trustee shall promptly mail notice thereof to all Noteholders.

     (b) Notwithstanding the provisions of Section 8.02(a) and Section 8.02(b), and subject to the provisions of Section 8.01, at the effective time of such Merger Event, the right to exchange each $1,000 principal amount of Notes will be changed to a right to exchange such Note by reference to the kind and amount of cash, securities or other property or assets that a Holder of a number of Common Shares equal to the Exchange Rate immediately prior to such transaction would have owned or been entitled to receive (the “Reference Property”) such that from and after the effective time of such transaction, a Noteholder will be entitled thereafter to exchange its Notes into cash (up to the aggregate principal amount thereof) and the same type (and in the same proportion) of Reference Property, based on the Daily Settlement Amounts of Reference Property in an amount equal to the applicable Exchange Rate, as described under Section 8.02(a) or Section 8.02(b), as applicable. For purposes of determining the constitution of Reference Property, the type and amount of consideration that a Holder of Common Shares would have been entitled to in the case of reclassifications, consolidations, mergers, sales or conveyance of assets or other transactions that cause the Common Shares to be converted into the right to receive more than a single type of consideration (determined based in part upon any form of shareholder election) will be deemed to be the weighted average of the types and amounts of consideration received by the Holders of Common Shares that affirmatively make such an election. The Company shall not become a party to any such transaction unless its terms are consistent with the preceding. None of the foregoing provisions shall affect the right of a Holder of Notes to exchange its Notes in accordance with the provisions of this Article 8 prior to the effective time of such Merger Event.

     (c) The Company shall cause notice of the execution of such supplemental indenture to be mailed to each Noteholder, at his address appearing on the Security Register provided for in Section 2.06, within thirty (30) days after execution thereof. Failure to deliver such notice shall not affect the legality or validity of such supplemental indenture.

     (d) The above provisions of this Section shall similarly apply to successive Merger Events.

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     Section 8.07 Certain Covenants. The Company covenants that all Common Shares delivered upon exchange of Notes will be fully paid and non-assessable by Archstone-Smith Trust and free from all taxes, liens and changes with respect to the issue thereof.

     Section 8.08 Responsibility of Trustee. The Trustee and any other Exchange Agent shall not at any time be under any duty or responsibility to any Noteholder to determine the Exchange Rate or whether any facts exist which may require any adjustment of the Exchange Rate, or with respect to the nature or extent or calculation of any such adjustment when made, or with respect to the method employed, or herein or in any supplemental indenture provided to be employed, in making the same. The Trustee and any other Exchange Agent shall not be accountable with respect to the validity or value (or the kind or amount) of any Common Shares, or of any securities or property, which may at any time be issued or delivered upon the exchange of any Note; and the Trustee and any other Exchange Agent make no representations with respect thereto. Neither the Trustee nor any Exchange Agent shall be responsible for any failure of the Company to transfer or deliver any Common Shares or certificates therefor or other securities or property or cash upon the surrender of any Note for the purpose of exchange or to comply with any of the duties, responsibilities or covenants of the Company contained in this Article.

     Without limiting the generality of the foregoing, neither the Trustee nor any Exchange Agent shall be under any responsibility to determine the correctness of any provisions contained in any supplemental indenture entered into pursuant to Section 8.06 relating either to the kind or amount of shares of stock or securities or property (including cash) receivable by Noteholders upon the exchange of their Notes after any event referred to in such Section 8.06 or to any adjustment to be made with respect thereto, but, subject to the provisions of Article 6 of the Base Indenture, may accept as conclusive evidence of the correctness of any such provisions, and shall be protected in relying upon, the Officers’ Certificate with respect thereto.

     Section 8.09 Notice to Holders Prior to Certain Actions.

     In case:

     (a) Archstone-Smith Trust shall declare a dividend (or any other distribution) on its Common Shares that would require an adjustment in the Exchange Rate pursuant to Section 8.04; or

     (b) Archstone-Smith Trust shall authorize the granting to all of the Holders of its Common Shares of rights or warrants to subscribe for or purchase any share of any class or any other rights or warrants;

     (c) of any reclassification of the Common Shares (other than a subdivision or combination of outstanding Common Shares, or a change in par value, or from par value to no par value, or from no par value to par value), or of any consolidation or merger to which Archstone-Smith Trust is a party and for which approval of any shareholders of Archstone-Smith Trust is required, or of the sale or transfer of all or substantially all of the assets of Archstone-Smith Trust; or

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     (d) of the voluntary or involuntary dissolution, liquidation or winding-up of Archstone-Smith Trust,

the Company shall cause to be filed with the Trustee and to be mailed to each Noteholder at his address appearing on the Security Register as promptly as possible but in any event at least ten (10) days prior to the applicable date specified in clause (x) or (y) below, as the case may be, a notice stating (x) the date on which a record is to be taken for the purpose of such dividend, distribution or rights or warrants, or, if a record is not to be taken, the date as of which the Holders of Common Shares of record to be entitled to such dividend, distribution or rights are to be determined, or (y) the date on which such reclassification, consolidation, merger, sale, transfer, dissolution, liquidation or winding-up is expected to become effective or occur, and the date as of which it is expected that Holders of Common Shares of record shall be entitled to exchange their Common Shares for securities or other property deliverable upon such reclassification, consolidation, merger, sale, transfer, dissolution, liquidation or winding-up. Failure to give such notice, or any defect therein, shall not affect the legality or validity of such dividend, distribution, reclassification, consolidation, merger, sale, transfer, dissolution, liquidation or winding-up.

     Section 8.10 Shareholder Rights Plans. Upon exchange of the Notes, the Noteholders shall receive, in addition to any Common Shares issuable upon such exchange, the associated rights issued under any shareholder rights plan that Archstone-Smith Trust adopts. If, and only if, the Noteholders receive rights under such shareholder rights plans as described in the preceding sentence upon exchange of their Notes, then no other adjustment pursuant to this Article 8 shall be made in connection with such shareholder rights plans.

     Section 8.11 Ownership Limit. Notwithstanding any other provision of this Third Supplemental Indenture or the Notes, no Holder of Notes shall be entitled to exchange such Notes for Common Shares to the extent that receipt of such shares would cause such Holder (together with such Holder’s affiliates) to exceed the applicable ownership limit contained in the declaration of trust of Archstone-Smith Trust as then in effect.

     Section 8.12 Net Share Settlement Election. Notwithstanding anything to the contrary in this Article 8, at any time on or prior to the twenty-sixth Business Day immediately preceding the Maturity Date, the Company may irrevocably elect (“Net Share Settlement Election”) to satisfy the its Exchange Obligation with respect to the Notes to be exchanged after the date of such election with a combination of cash in an amount equal to not less than the lower of (x) the aggregate Daily Exchange Value and (y) the aggregate principal amount of the Notes to be exchanged, and Common Shares in excess thereof, as described in Section 8.01 and Section 8.02 herein. Such election would be in the sole discretion of the Company without the consent of the Holders of Notes. If the Company makes such election, it shall notify the Trustee and the Holders of Notes at their addresses shown in the Security Register.

     Section 8.13 Registration of Common Shares. If the Company elects to deliver Common Shares upon exchange of the Notes, the Company shall deliver such Common Shares pursuant to a registration statement that has been declared or otherwise become automatically effective upon filing under the Securities Act; provided that if the Company cannot deliver to exchanging Noteholders Common

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Shares registered pursuant to an effective registration statement, the Company has the right to deliver to those exchanging Noteholders Common Shares that have not been registered under the Securities Act or Common Units in accordance with Section 8.02(k) in satisfaction of all or a portion of the Company’s obligations under the Notes, at the election of the Company.

ARTICLE 9
Repurchase of Notes at Option of Holders

     Section 9.01 Repurchase of Securities at Option of the Holder on Specified Dates.

     (a) The provisions of Article Thirteen of the Base Indenture shall not be applicable to the Notes.

     (b) At the option of the Holder thereof, Notes shall be repurchased by the Company in accordance with the provisions of the Notes on July 18, 2011, July 15, 2016, July 15, 2021, July 15, 2026, and July 15, 2031 (each, a “Put Right Repurchase Date”) at a repurchase price per Note equal to 100% of the aggregate principal amount of the Notes being repurchased, together with any accrued and unpaid interest up to, but not including, such Put Right Repurchase Date (the “Put Right Repurchase Price”).

     Repurchases of Notes by the Company pursuant to this Section 9.01 shall be made, at the option of the Holder thereof, upon:

     (i) delivery to the Trustee (or other Paying Agent appointed by the Company) by the Holder of a written notice of purchase (a “Put Right Repurchase Notice”) in the form set forth on the reverse of the Note at any time from the opening of business on the date that is 25 Business Days prior to the applicable Put Right Repurchase Date until the Close of Business on the fifth Business Day prior to such Put Right Repurchase Date stating:

     (A) if certificated, the certificate numbers of the Notes to be delivered for repurchase;

     (B) the portion of the principal amount of the Notes to be repurchased, which must be $1,000 or an integral multiple thereof; and

     (C) that the Notes are to be repurchased as of the applicable Put Right Repurchase Date pursuant to the terms and conditions specified in the Notes and in this Third Supplemental Indenture; and

     (ii) delivery of such Note to the Paying Agent prior to, on or after the Put Right Repurchase Date (together with all necessary endorsements) at the offices of the Paying Agent, such delivery being a condition to receipt by the Holder of the Put Right Repurchase Price therefor, which shall be so paid pursuant to this Section 9.01 only if the Note so delivered to the Paying Agent shall conform in all respects to the description thereof in the related Put Right Repurchase Notice, as determined by the Company.

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     The Company shall repurchase from the Holder thereof, pursuant to this Section 9.01, a portion of a Note if the principal amount of such portion is $1,000 or an integral multiple of $1,000. Provisions of this Third Supplemental Indenture that apply to the repurchase of all of a Note also apply to the repurchase of such portion of such Note.

     Any repurchase by the Company contemplated pursuant to the provisions of this Section 9.01 shall be consummated by the delivery of the consideration to be received by the Holder promptly following the later of the Put Right Repurchase Date and the time of delivery of the Note.

     The Trustee (or other Paying Agent appointed by the Company) shall promptly notify the Company of the receipt by it of any Put Right Repurchase Notice or written notice of withdrawal thereof in accordance with the provisions of Section 9.01(e).

     Any Note that is to be repurchased only in part shall be surrendered to the Trustee (with, if the Company or the Trustee so requires, due endorsement by, or a written instrument of transfer in form satisfactory to the Company and the Trustee duly executed by the Holder thereof or his attorney duly authorized in writing), and the Company shall execute, and the Trustee shall authenticate and make available for delivery to the Holder of such Note without service charge, a new Note or Notes, containing identical terms and conditions, each in an authorized denomination in aggregate principal amount equal to and in exchange for the unrepurchased portion of the principal of the Note so surrendered.

     (c) In connection with any purchase of Notes pursuant to this Section 9.01, the Company shall give written notice of the Put Right Repurchase Date to the Holders (the “Company Put Right Notice”).

     The Company Put Right Notice shall be sent by first-class mail to the Trustee and to each Holder (and to each beneficial owner as required by applicable law) that has delivered a Put Right Repurchase Notice within 10 Business Days of receipt of such Put Right Repurchase Notice, or, if a shorter period, at least two Business Days prior to any Put Right Repurchase Date (the “Company Put Right Notice Date”). Each Company Put Right Notice shall include a form of Put Right Repurchase Notice to be completed by a Noteholder and shall state:

     (i) the Put Right Repurchase Price and the Exchange Price;

     (ii) the name and address of the Paying Agent and the Exchange Agent;

     (iii) that Notes as to which a Put Right Repurchase Notice has been given may be exchanged in accordance with Article 8 only if the applicable Put Right Repurchase Notice has been withdrawn in accordance with the terms of this Third Supplemental Indenture;

     (iv) that Notes must be surrendered to the Paying Agent to collect payment;

     (v) that the Put Right Repurchase Price for any Note as to which a Put Right Repurchase Notice has been given and not withdrawn will be paid promptly

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following the later of the Put Right Repurchase Date and the time of surrender of such Note as described in subclause (iv) above;

     (vi) the procedures the Holder must follow to exercise rights under this Section and a brief description of those rights;

     (vii) briefly, the exchange rights of the Notes;

     (viii) the procedures for withdrawing a Put Right Repurchase Notice (including pursuant to the terms of Section 9.01(e);

     (ix) that, unless the Company defaults in making payment on Notes for which a Put Right Repurchase Notice has been submitted, interest on the Notes in respect of which a Put Right Repurchase Notice has been delivered and not withdrawn will cease to accrue on the Put Right Repurchase Date; and

     (x) the CUSIP number of the Notes.

     If any of the Notes are to be redeemed in the form of a Global Note, the Company shall modify such notice to the extent necessary to accord with the procedures of the Depositary applicable to redemptions.

     At the Company’s request, the Trustee shall give such Company Put Right Notice in the Company’s name and at the Company’s expense; provided, however, that, in all cases, the text of such Company Put Right Notice shall be prepared by the Company.

     (d) Upon receipt by the Trustee (or other Paying Agent appointed by the Company) of the Put Right Repurchase Notice specified in Section 9.01(b)(i), the Holder of the Note in respect of which such Put Right Repurchase Notice was given shall (unless such Put Right Repurchase Notice is withdrawn as specified in Section 9.01(e)) thereafter be entitled to receive solely the Put Right Repurchase Price with respect to such Note. Such Put Right Repurchase Price shall be paid to such Holder, subject to receipt of funds by the Paying Agent, promptly following the later of (x) the Put Right Repurchase Date with respect to such Note (provided the conditions in Section 9.01(b) have been satisfied) and (y) the time of delivery of such Note to the Paying Agent by the Holder thereof in the manner required by Section 9.01(b)(i). Notes in respect of which a Put Right Repurchase Notice has been given by the Holder thereof may not be exchanged pursuant to Article 8 on or after the date of the delivery of such Put Right Repurchase Notice, unless such Put Right Repurchase Notice has first been validly withdrawn as specified in Section 9.01(e).

     (e) A Put Right Repurchase Notice may be withdrawn by means of a written notice of withdrawal delivered to the office of the Paying Agent in accordance with the Put Right Repurchase Notice at any time prior to 10:00 A.M. New York City time on the fourth business on the Business Day prior to the Put Right Repurchase Date specifying:

     (i) if certificated Notes have been issued, the certificate numbers of the withdrawn Notes;

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     (ii) the principal amount of the Notes with respect to which such notice of withdrawal is being submitted; and

     (iii) the principal amount, if any, of such Notes that remains subject to the original Put Right Repurchase Notice, which portion must be in principal amounts of $1,000 or an integral multiple of $1,000;

provided, however, that if the Notes are not in certificated form, the notice must comply with appropriate procedures of the Depositary.

     A written notice of withdrawal of a Put Right Repurchase Notice shall be in the form set forth in the preceding paragraph.

     Upon receipt of a written notice of withdrawal, the Paying Agent shall promptly return to the Holders thereof any Notes in respect of which a Put Right Repurchase Notice has been withdrawn in accordance with the provisions of Section 9.01(f).

     (f) There shall be no repurchase of any Notes pursuant to this Section 9.01 if there has occurred (prior to, on or after, as the case may be, the giving, by the Holders of such Notes, of the required Put Right Repurchase Notice) and is continuing an Event of Default with respect to Notes of such series (other than a default in the payment of the Put Right Repurchase Price with respect to such Notes). The Paying Agent will promptly return to the respective Holders thereof any Notes held by it during the continuance of an Event of Default with respect to Notes of such series (other than a default in the payment of the Put Right Repurchase Price with respect to such Notes), in which case, upon such return, the Put Right Repurchase Notice with respect thereto shall be deemed to have been withdrawn.

     (g) Prior to 11:00 a.m. (local time in The City of New York) on the Put Right Repurchase Date, the Company shall deposit with the Trustee (or other Paying Agent appointed by the Company or if the Company is acting as its own Paying Agent, set aside, segregate and hold in trust in accordance with the terms of the Base Indenture as modified by this Third Supplemental Indenture) an amount (in immediately available funds if deposited on such Business Day) sufficient to pay the aggregate Put Right Repurchase Price of all the Notes or portions thereof which are to be purchased as of the Put Right Repurchase Date. The manner in which the deposit required by this Section 9.01(g) is made by the Company shall be at the option of the Company; provided that such deposit shall be made in a manner such that the Trustee or a Paying Agent shall have immediately available funds on the Put Right Repurchase Date.

     If the Trustee (or other Paying Agent appointed by the Company) holds, in accordance with the terms hereof, money sufficient to pay the Put Right Repurchase Price of any Note, then, on the Put Right Repurchase Date, such Note will cease to be Outstanding and the rights of the Holder in respect thereof shall terminate (other than the right to receive the Put Right Repurchase Price as aforesaid).

     To the extent that the aggregate amount of cash deposited by the Company pursuant to this Section 9.01(g) exceeds the aggregate Put Right Repurchase Price of the Notes or portions thereof that the Company is obligated to purchase, then promptly after the Put Right Repurchase

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Date the Trustee or a Paying Agent, as the case may be, shall return any such excess cash to the Company.

     Section 9.02 Repurchase at Option of Holders Upon a Fundamental Change.

     (a) If a Fundamental Change occurs at any time, then each Noteholder shall have the right, at such Holder’s option, to require the Company to repurchase all of such Holder’s Notes or any portion thereof that is a multiple of $1,000 principal amount, for cash on the date (the “Fundamental Change Repurchase Date”) specified by the Company that is not less than twenty (20) Business Days and not more than thirty-five (35) Business Days after the date of the Fundamental Change Company Notice (as defined below) at a repurchase price equal to 100% of the principal amount thereof, together with accrued and unpaid interest thereon to, but excluding, the Fundamental Change Repurchase Date (the “Fundamental Change Repurchase Price”).

     Repurchases of Notes under this Section 9.02 shall be made, at the option of the Holder thereof, upon:

     (i) delivery to the Trustee (or other Paying Agent appointed by the Company) by a Holder of a duly completed notice (the “Fundamental Change Repurchase Notice”) in the form set forth on the reverse of the Note prior to the Close of Business on the Fundamental Change Repurchase Date; and

     (ii) delivery or book-entry transfer of the Notes to the Trustee (or other Paying Agent appointed by the Company) at any time after delivery of the Fundamental Change Repurchase Notice (together with all necessary endorsements) at the Corporate Trust Office of the Trustee (or other Paying Agent appointed by the Company), such delivery being a condition to receipt by the Holder of the Fundamental Change Repurchase Price therefor; provided that such Fundamental Change Repurchase Price shall be so paid pursuant to this Section 9.02 only if the Note so delivered to the Trustee (or other Paying Agent appointed by the Company) shall conform in all respects to the description thereof in the related Fundamental Change Repurchase Notice.

     The Fundamental Change Repurchase Notice shall state:

     (A) if certificated, the certificate numbers of Notes to be delivered for repurchase;

     (B) the portion of the principal amount of Notes to be repurchased, which must be $1,000 or an integral multiple thereof; and

     (C) that the Notes are to be repurchased by the Company pursuant to the applicable provisions of the Notes and this Indenture.

     Any repurchase by the Company contemplated pursuant to the provisions of this Section 9.02 shall be consummated by the delivery of the consideration to be received by the Holder promptly following the later of the Fundamental Change Repurchase Date and the time of the book-entry transfer or delivery of the Note.

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     The Trustee (or other Paying Agent appointed by the Company) shall promptly notify the Company of the receipt by it of any Fundamental Change Repurchase Notice or written notice of withdrawal thereof in accordance with the provisions of Section 9.02(c).

     Any Note that is to be repurchased only in part shall be surrendered to the Trustee (with, if the Company or the Trustee so requires, due endorsement by, or a written instrument of transfer in form satisfactory to the Company and the Trustee duly executed by the Holder thereof or his attorney duly authorized in writing), and the Company shall execute, and the Trustee shall authenticate and make available for delivery to the Holder of such Note without service charge, a new Note or Notes, containing identical terms and conditions, each in an authorized denomination in aggregate principal amount equal to and in exchange for the unrepurchased portion of the principal of the Note so surrendered.

     (b) On or before the twentieth day after the occurrence of any Fundamental Change, the Company shall provide to all Holders of record of the Notes and the Trustee and Paying Agent a notice (the “Fundamental Change Company Notice”) of the occurrence of such Fundamental Change and of the repurchase right at the option of the Holders arising as a result thereof. Such mailing shall be by first class mail. Simultaneously with providing such Fundamental Change Company Notice, the Company shall publish a notice containing the information included therein once in a newspaper of general circulation in The City of New York or publish such information on the Company’s website or through such other public medium as the Company may use at such time.

     Each Fundamental Change Company Notice shall specify:

     (i) the events causing the Fundamental Change;

     (ii) the date of the Fundamental Change;

     (iii) that the Holder must exercise the repurchase right on or prior to the Close of Business on the Fundamental Change Repurchase Date;

     (iv) the Fundamental Change Repurchase Price;

     (v) the Fundamental Change Repurchase Date;

     (vi) the name and address of the Paying Agent and the Exchange Agent;

     (vii) the applicable Exchange Rate and any adjustments to the applicable Exchange Rate;

     (viii) that the Notes with respect to which a Fundamental Change Repurchase Notice has been delivered by a Holder may be exchanged only if the Holder withdraws the Fundamental Change Repurchase Notice in accordance with the terms of this Indenture; and

     (ix) the procedures that Holders must follow to require the Company to repurchase their Notes.

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     No failure of the Company to give the foregoing notices and no defect therein shall limit the Noteholders’ repurchase rights or affect the validity of the proceedings for the repurchase of the Notes pursuant to this Section 9.02.

     (c) A Fundamental Change Repurchase Notice may be withdrawn by means of a written notice of withdrawal delivered to the Paying Agent in accordance with the Fundamental Change Company Notice at any time prior to the Close of Business on the Business Day prior to the Fundamental Change Repurchase Date, specifying:

     (i) the principal amount of the Notes with respect to which such notice of withdrawal is being submitted;

     (ii) if certificated Notes have been issued, the certificate numbers of the withdrawn Notes; and

     (iii) the principal amount, if any, of such Notes that remains subject to the original Fundamental Change Repurchase Notice, which portion must be in principal amounts of $1,000 or an integral multiple of $1,000;

provided, however, that if the Notes are not in certificated form, the notice must comply with appropriate procedures of the Depositary.

     (d) On or prior to 11:00 a.m. (local time in The City of New York) on the second Business Day following the Fundamental Change Repurchase Date, the Company will deposit with the Trustee (or other Paying Agent appointed by the Company or if the Company is acting as its own Paying Agent, set aside, segregate and hold in trust in accordance with this Indenture) an amount of money sufficient to repurchase on the Fundamental Change Repurchase Date all of the Notes to be repurchased on such date at the Fundamental Change Repurchase Price. Subject to receipt of funds and/or Notes by the Trustee (or other Paying Agent appointed by the Company), payment for Notes surrendered for repurchase (and not withdrawn) prior to the Close of Business on the Fundamental Change Repurchase Date will be made promptly after the later of (x) the Fundamental Change Repurchase Date with respect to such Note (provided the Holder has satisfied the conditions to the payment of the Fundamental Change Repurchase Price in Section 9.02), and (y) the time of book-entry transfer or the delivery of such Note to the Trustee (or other Paying Agent appointed by the Company) by the Holder thereof in the manner required by Section 9.02 by mailing checks for the amount payable to the Holders of such Notes entitled thereto as they shall appear in the Security Register, provided, however, that payments to the Depositary shall be made by wire transfer of immediately available funds to the account of the Depositary or its nominee. The Trustee shall, promptly after such payment and upon written demand by the Company, return to the Company any funds in excess of the Fundamental Change Repurchase Price.

     (e) If the Trustee (or other Paying Agent appointed by the Company) holds money or securities sufficient to repurchase on the Fundamental Change Repurchase Date all the Notes or portions thereof that are to be purchased as of the second Business Day following the Fundamental Change Repurchase Date, then on and after the Fundamental Change Repurchase Date (i) such Notes will cease to be Outstanding, (ii) interest will cease to accrue on such Notes, and (iii) all other rights of the Holders of such Notes will terminate, whether or not book-entry transfer of the Notes has been made or the Notes have been delivered to the Trustee or Paying Agent, other than the right to receive the Fundamental Change Repurchase Price upon delivery of the Notes.

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ARTICLE 10
Miscellaneous Provisions

     Section 10.01 Ratification of Base Indenture. Except as expressly modified or amended hereby, the Base Indenture, as modified by the First Supplemental Indenture and the Second Supplemental Indenture (which is not applicable to the Notes), continues in full force and effect and is in all respects confirmed, ratified and preserved.

     Section 10.02 Provisions Binding on Company’s Successors. All the covenants, stipulations, promises and agreements of the Company contained in this Third Supplemental Indenture shall bind its successors and assigns whether so expressed or not.

     Section 10.03 Official Acts by Successor Corporation. Any act or proceeding by any provision of this Third Supplemental Indenture authorized or required to be done or performed by any board, committee, trustee or officer of the Company shall and may be done and performed with like force and effect by the like board, committee, trustee or officer of any corporation, trust or other entity that shall at the time be the lawful sole successor of the Company.

     Section 10.04 Addresses for Notices, Etc. Any notice or demand which by any provision of this Third Supplemental Indenture is required or permitted to be given or served by the Trustee or by the Noteholders on the Company shall be deemed to have been sufficiently given or made, for all purposes if given or served by being deposited postage prepaid by registered or certified mail in a post office letter box addressed (until another address is filed by the Company with the Trustee) to Archstone-Smith Operating Trust, 9200 E. Panorama, Suite 400, Englewood, Colorado 80112, Attention: General Counsel. Any notice, direction, request or demand hereunder to or upon the Trustee shall be deemed to have been sufficiently given or made, for all purposes, if given or served by being deposited postage prepaid by registered or certified mail in a post office letter box addressed to U.S. Bank National Association, Attention: Corporate Trust Administration, 100 Wall Street, Suite 1600, New York, New York 10005.

     The Trustee, by notice to the Company, may designate additional or different addresses for subsequent notices or communications.

     Any notice or communication mailed to a Noteholder shall be mailed to him by first class mail, postage prepaid, at his address as it appears on the Security Register and shall be sufficiently given to him if so mailed within the time prescribed.

     Failure to mail a notice or communication to a Noteholder or any defect in it shall not affect its sufficiency with respect to other Noteholders. If a notice or communication is mailed in the manner provided above, it is duly given, whether or not the addressee receives it.

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     Section 10.05 Governing Law. THIS THIRD SUPPLEMENTAL INDENTURE AND EACH NOTE ISSUED PURSUANT HERETO SHALL BE DEEMED TO BE A CONTRACT MADE UNDER THE LAWS OF THE STATE OF NEW YORK, AND FOR ALL PURPOSES SHALL BE CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK APPLICABLE TO CONTRACTS ENTERED INTO AND TO BE PERFORMED THEREIN.

     Section 10.06 Evidence of Compliance with Conditions Precedent; Certificates and Opinions of Counsel to Trustee. Upon any application or demand by the Company to the Trustee to take any action under any of the provisions of this Indenture, the Company shall furnish to the Trustee an Officers’ Certificate stating that all conditions precedent, if any, provided for in this Indenture relating to the proposed action have been complied with, and an Opinion of Counsel stating that, in the opinion of such counsel, all such conditions precedent have been complied with.

     Each certificate or opinion provided for by or on behalf of the Company in this Indenture and delivered to the Trustee with respect to compliance with a condition or covenant provided for in this Indenture shall include (i) a statement that the person making such certificate or opinion has read such covenant or condition; (ii) a brief statement as to the nature and scope of the examination or investigation upon which the statement or opinion contained in such certificate or opinion is based; (iii) a statement that, in the opinion of such person, he has made such examination or investigation as is necessary to enable him to express an informed opinion as to whether or not such covenant or condition has been complied with; and (iv) a statement as to whether or not, in the opinion of such person, such condition or covenant has been complied with.

     Section 10.07 Non-Business Day. Section 113 of the Base Indenture shall also apply to any Fundamental Change Purchase Date, Put Right Repurchase Date or Exchange Date in respect of the Notes.

     Section 10.08 No Security Interest Created. Nothing in this Indenture or in the Notes, expressed or implied, shall be construed to constitute a security interest under the Uniform Commercial Code or similar legislation, as now or hereafter enacted and in effect, in any jurisdiction.

     Section 10.09 Benefits of Indenture. Nothing in this Indenture or in the Notes, expressed or implied, shall give to any person, other than the parties hereto, any Paying Agent, any Authenticating Agent, any Security Registrar and their successors hereunder, the Noteholders, any benefit or any legal or equitable right, remedy or claim under this Indenture.

     Section 10.10 Table of Contents, Headings, Etc. The table of contents and the titles and headings of the articles and sections of this Third Supplemental Indenture have been inserted for convenience of reference only, are not to be considered a part hereof, and shall in no way modify or restrict any of the terms or provisions hereof.

42

     Section 10.11 Execution in Counterparts. This Third Supplemental Indenture may be executed in any number of counterparts, each of which shall be an original, but such counterparts shall together constitute but one and the same instrument.

     Section 10.12 Trustee. The Trustee makes no representations as to the validity or sufficiency of this Third Supplemental Indenture. The statements and recitals herein are deemed to be those of the Company and not of the Trustee.

     Section 10.13 Further Instruments and Acts. Upon request of the Trustee, the Company will execute and deliver such further instruments and do such further acts as may be reasonably necessary or proper to carry out more effectively the purposes of this Indenture.

     Section 10.14 Waiver of Jury Trial. EACH OF THE COMPANY AND THE TRUSTEE HEREBY IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR RELATING TO THIS INDENTURE, THE NOTES OR THE TRANSACTION CONTEMPLATED HEREBY.

     Section 10.15 Force Majeure. In no event shall the Trustee be responsible or liable for any failure or delay in the performance of its obligations hereunder arising out of or caused by, directly or indirectly, forces beyond its control, including, without limitation, strikes, work stoppages, accidents, acts of war or terrorism, civil or military disturbances, nuclear or natural catastrophes or acts of God, and interruptions, loss or malfunctions of utilities, communications or computer (software and hardware) services; it being understood that the Trustee shall use reasonable efforts which are consistent with accepted practices in the banking industry to resume performance as soon as practicable under the circumstances.

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     IN WITNESS WHEREOF, the parties hereto have caused this Third Supplemental Indenture to be duly executed as of the date first written above.

ARCHSTONE-SMITH OPERATING TRUST
By:	/s/ Rick D. Jacobsen
	Name:	Rick D. Jacobsen
	Title:	Executive Vice President

[SEAL]
Attest:
By:	/s/ Caroline Bower
	Name:	Caroline Bower
	Title:	Secretary

U.S. BANK NATIONAL ASSOCIATION,
	as Trustee, as aforesaid
By:	/s/ Thomas Tabor
	Authorized Person

Attest:
By:	/s/ Jean Clarke
	Name:	Jean Clarke
	Title:	Assistant Vice President

SCHEDULE A

	Share Price
Effective Date	$52.14		$55.00		$60.00		$65.00		$70.00		$75.00		$85.00
July 14, 2006		3.4585		2.8269		1.9550		1.3141		0.8468		0.5126		0.1188
July 18, 2007		3.4529		2.7997		1.9038		1.2543		0.7892		0.4620		0.0920
July 18, 2008		3.4290		2.7442		1.8167		1.1573		0.6983		0.3860		0.0532
July 18, 2009		3.3796		2.6484		1.6716		1.0009		0.5559		0.2721		0.0100
July 18, 2010		3.3164		2.4923		1.4113		0.7159		0.3093		0.0944		0.0000
July 18, 2011		3.4585		2.4612		0.9461		0.0000		0.0000		0.0000		0.0000

EX-4.2

Exhibit 4.2

Unless this certificate is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to the Company (as defined below) or its agent for registration of transfer, exchange, or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name as is requested by an authorized representative of DTC (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), any transfer, pledge, or other use hereof for value or otherwise by or to any person is wrongful inasmuch as the registered owner hereof, Cede & Co., has an interest herein.

REGISTERED	PRINCIPAL AMOUNT
No.:	$
CUSIP No.: 039584 AC 1

ARCHSTONE-SMITH OPERATING TRUST
4.00% EXCHANGEABLE SENIOR NOTE DUE 2036

     ARCHSTONE-SMITH OPERATING TRUST, a real estate investment trust organized and existing under the laws of the State of Maryland (hereinafter called the “Company,” which term shall include any successor under the Indenture hereinafter referred to), for value received, hereby promises to pay to CEDE & CO., or registered assigns, upon presentation, the principal sum of                                                                                          on July 15, 2036 and to pay interest on the outstanding principal amount thereon from July 14, 2006 or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually in arrears on January 15 and July 15 in each year, commencing on January 15, 2007, at the rate of 4.00% per annum, until the entire principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly provided for on any Interest Payment Date will, as provided in the Indenture, be paid to the Person in whose name this Note (or one or more Predecessor Notes) is registered at the Close of Business on the Record Date for such interest which shall be the January 1 or July 1, as the case may be, next preceding such Interest Payment Date. Payment of the principal of and interest on this Note will be made at the office or agency of the Company maintained for that purpose in the City of St. Paul, State of Minnesota, or elsewhere as provided in the Indenture, in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Company, payment of interest may be made by (i) check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (ii) transfer to an account of the Person entitled thereto located inside the United States.

     Each Note of this series is one of a duly authorized issue of securities of the Company (herein called the “Notes”), issued and to be issued in one or more series under an Indenture, dated as of February 1, 1994 (the “Base Indenture”), between Archstone-Smith Operating Trust (formerly known as Archstone Communities Trust and prior thereto as Security Capital Pacific Trust and Property Trust of America) (the “Company”) and Morgan Guaranty Trust Company of New York (as predecessor to State Street Bank and Trust Company, which became successor trustee pursuant to the First Supplemental Indenture, as defined below); as supplemented by the First Supplemental Indenture, dated as of February 2, 1994, between the Company and U.S. Bank National Association (the “Trustee”), as successor in interest to State Street Bank and Trust Company; as further supplemented by the Second Supplemental Indenture, dated as of August 2,

2004, between the Company and the Trustee (the “Second Supplemental Indenture”); and as further supplemented by the Third Supplemental Indenture, dated as of the date hereof, between the Company and the Trustee (the “Third Supplemental Indenture”). The Base Indenture, as supplemented by the First Supplemental Indenture and the Third Supplemental Indenture shall be referred to herein as the “Indenture.” The Second Supplemental Indenture is not applicable to the Notes. Reference is hereby made to the Indenture for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Notes and of the terms upon which the Notes are, and are to be, authenticated and delivered. This Note is one of the series designated on the first page hereof, initially limited in aggregate principal amount to $400,000,000, subject to the Company’s right to increase the aggregate principal amount of such series from time to time.

     In case an Event of Default, as defined in the Indenture, shall have occurred and be continuing, the principal of and interest on all Notes may be declared, and upon said declaration shall become, due and payable, in the manner, with the effect and subject to the conditions provided in the Third Supplemental Indenture.

     As provided in and subject to the provisions of the Indenture, unless the principal of all of the Notes of this series at the time Outstanding shall already have become due and payable, the Holder of this Note shall not have the right to institute any proceeding with respect to the Indenture or for the appointment of a receiver or trustee or for any other remedy thereunder, unless such Holder shall have previously given the Trustee written notice of a continuing Event of Default with respect to the Notes of this series, the Holders of not less than 25% in principal amount of the Notes of this series at the time Outstanding shall have made written request to the Trustee to institute proceedings in respect of such Event of Default as Trustee and offered the Trustee reasonable indemnity and the Trustee shall not have received from the Holders of a majority in principal amount of Notes of this series at the time Outstanding a direction inconsistent with such request, and the Trustee shall have failed to institute any such proceeding for 60 days after receipt of such notice, request and offer of indemnity. The foregoing shall not apply to any suit instituted by the Holder of this Note for the enforcement of any payment of principal hereof or any interest on or after the respective due dates expressed herein.

     Prior to July 18, 2011, the Company may not redeem the Notes except to preserve Archstone-Smith Trust’s status as a real estate investment trust as described in Section 3.01 of the Third Supplemental Indenture. Subject to the terms and conditions of the Indenture, on or after July 18, 2011, the Company shall have the right to redeem the Notes, in whole or from time to time in part, at a price equal to 100% of the principal amount of the Notes being redeemed, plus accrued and unpaid interest. Any such redemption shall be upon at least 30 days’ and no more than 60 days’ notice to Holders of the Notes.

     Subject to the terms and conditions of the Indenture, the Company will make all payments and deliveries in respect of the Fundamental Change Repurchase Price, the Put Right Repurchase Price, the redemption price and the principal amount on the Maturity Date, as the case may be, to the Holder who surrenders a Note to a Paying Agent to collect such payments in respect of the Note. The Company will pay cash amounts in money of the United States that at the time of payment is legal tender for payment of public and private debts.

2

     The Indenture contains provisions permitting the Company and the Trustee in certain circumstances, without the consent of the Holders of the Notes, and in other circumstances, with the consent of the Holders of not less than a majority in aggregate principal amount of the Notes at the time Outstanding, evidenced as in the Indenture provided, to execute supplemental indentures adding any provisions to or changing in any manner or eliminating any of the provisions of the Indenture or of any supplemental indenture or modifying in any manner the rights of the Holders of the Notes; provided, however, that no such supplemental indenture shall make any of the changes set forth in Section 6.02 of the Third Supplemental Indenture, without the consent of each Holder of an Outstanding Note affected thereby. It is also provided in the Indenture that the Holders of a majority in aggregate principal amount of the Notes at the time Outstanding may on behalf of the Holders of all of the Notes waive any past default or Event of Default under the Indenture and its consequences except as provided in the Indenture. Any such consent or waiver by the Holder of this Note (unless revoked as provided in the Indenture) shall be conclusive and binding upon such Holder and upon all future Holders and owners of this Note and any Notes which may be issued in exchange or substitution hereof, irrespective of whether or not any notation thereof is made upon this Note or such other Notes.

     No reference herein to the Indenture and no provision of this Note or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of and accrued and unpaid interest on this Note at the place, at the respective times, at the rate and in the lawful money herein prescribed.

     The Notes are issuable in registered form without coupons in denominations of $1,000 principal amount and integral multiples thereof. At the office or agency of the Company referred to on the face hereof, and in the manner and subject to the limitations provided in the Indenture, without payment of any service charge but with payment of a sum sufficient to cover any tax or other governmental charge that may be imposed in connection with any registration or exchange of Notes, Notes may be exchanged for a like aggregate principal amount of Notes of other authorized denominations.

     The Notes are not subject to redemption through the operation of any sinking fund.

     Upon the occurrence of a Fundamental Change, the Holder has the right, at such Holder’s option, to require the Company to repurchase all of such Holder’s Notes or any portion thereof (in principal amounts of $1,000 or integral multiples thereof) on the Fundamental Change Repurchase Date at a price equal to 100% of the principal amount of the Notes such Holder elects to require the Company to repurchase, together with accrued and unpaid interest to but excluding the Fundamental Change Repurchase Date. The Company or, at the written request of the Company, the Trustee shall mail to all Holders of record of the Notes a notice of the occurrence of a Fundamental Change and of the repurchase right arising as a result thereof on or before the twentieth day after the occurrence of any Fundamental Change.

     On July 18, 2011, July 15, 2016, July 15, 2021, July 15, 2026, and July 15, 2031, the Holder has the right, at such Holder’s option, to require the Company to repurchase all of such Holder’s Notes or any portion thereof (in principal amounts of $1,000 or integral multiples thereof) at a price equal to 100% of the principal amount of the Notes such Holder elects to require the Company to repurchase, together with accrued and unpaid interest to but excluding

3

the Put Right Repurchase Date. Holders shall submit their Notes for repurchase to the Paying Agent at any time from the opening of business on the date that is 25 Business Days prior to the applicable Put Right Repurchase Date until the Close of Business on the fifth Business Day prior to the Put Right Repurchase Date.

     Subject to the provisions of the Indenture, the Holder hereof has the right, at its option, on and after July 18, 2011, or earlier upon the occurrence of certain conditions specified in the Indenture and prior to the Close of Business on the Trading Day immediately preceding the Maturity Date, to exchange any Notes or portion thereof which is $1,000 or an integral multiple thereof, into cash, Common Shares or a combination thereof, in each case at the Exchange Rate specified in the Indenture, as adjusted from time to time as provided in the Indenture. The initial Exchange Rate is 15.7206 shares for each $1,000 principal amount of Notes. No fractional Common Shares will be issued upon any exchange, but an adjustment in cash will be paid to the Holder, as provided in the Indenture, in respect of any fraction of a share which would otherwise be issuable upon the surrender of any Note or Notes for exchange. No adjustment shall be made for dividends or any shares issued upon exchange of such Note except as provided in the Indenture.

     Upon due presentment for registration of transfer of this Note at the office or agency of the Company, a new Note or Notes of authorized denominations for an equal aggregate principal amount will be issued to the transferee in exchange thereof, subject to the limitations provided in the Indenture, without charge except for any tax, assessments or other governmental charge imposed in connection therewith.

     The Company, the Trustee, any Authenticating Agent, any Paying Agent, any Exchange Agent and any Security Registrar may deem and treat the registered Holder hereof as the absolute owner of this Note (whether or not this Note shall be overdue and notwithstanding any notation of ownership or other writing hereon), for the purpose of receiving payment hereof, or on account hereof, for the exchange hereof and for all other purposes, and neither the Company nor the Trustee nor any other Authenticating Agent nor any Paying Agent nor any other Exchange Agent nor any Security Registrar shall be affected by any notice to the contrary. All payments made to or upon the order of such registered Holder shall, to the extent of the sum or sums paid, satisfy and discharge liability for monies payable on this Note.

     No recourse for the payment of the principal of, or accrued and unpaid interest on, this Note, or for any claim based hereon or otherwise in respect hereof, and no recourse under or upon any obligation, covenant or agreement of the Company in the Indenture or any indenture supplemental thereto or in any Note, or because of the creation of any indebtedness represented thereby, shall be had against any incorporator, shareholder, employee, agent, officer, director, trustee or subsidiary, as such, past, present or future, of the Company or of any successor corporation, either directly or through the Company or any successor corporation, whether by virtue of any constitution, statute or rule of law or by the enforcement of any assessment or penalty or otherwise, all such liability being, by the acceptance hereof and as part of the consideration for the issue hereof, expressly waived and released.

4

     Terms used in this Note and defined in the Indenture are used herein as therein defined.

     Customary abbreviations may be used in the name of a Holder or an assignee, such as TEN COM (=tenants in common), TENANT (=tenants by the entireties), JT TEN (=joint tenants with right of survivorship and not as tenants in common), CUST (=custodian), and U/G/M/A (=Uniform gift to Minors Act).

     THE INDENTURE AND THE NOTES, INCLUDING THIS NOTE (WHICH SHALL BE DEEMED A CONTRACT MADE UNDER THE LAWS OF THE STATE OF NEW YORK), SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

     Pursuant to a recommendation promulgated by the Committee on Uniform Security Identification Procedures, the Company has caused “CUSIP” numbers to be printed on the Notes of this series as a convenience to the Holders of such Notes. No representation is made as to the correctness or accuracy of such CUSIP numbers as printed on the Notes, and reliance may be placed only on the other identification numbers printed hereon.

     No Holder of Notes shall be entitled to exchange such Notes for Common Shares to the extent that receipt of such Common Shares would cause such Holder (together with such Holder’s affiliates) to exceed the applicable ownership limit contained in the declaration of trust of Archstone-Smith Trust as then in effect.

[This space intentionally left blank.]

5

     Unless the certificate of authentication hereon has been executed by or on behalf of the Trustee by manual signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

     IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed by the undersigned officer.

	ARCHSTONE-SMITH OPERATING TRUST
(Seal)
	By:
		Name:
		Title:

Attest

By:
	Name:
	Title:

TRUSTEE’S CERTIFICATE OF AUTHENTICATION:

     This is one of the Notes of the series designated therein referred to in the within-mentioned Indenture.

U.S. BANK NATIONAL ASSOCIATION, as Trustee

By:
	Authorized Officer

ASSIGNMENT FORM

FOR VALUE RECEIVED, the undersigned hereby
sells, assigns and transfers unto

PLEASE INSERT SOCIAL
SECURITY OR OTHER IDENTIFYING
NUMBER OF ASSIGNEE

(Please Print or Typewrite Name and Address including
Zip Code of Assignee)

the within Note of Archstone-Smith Operating Trust and hereby does irrevocably constitute and appoint

	Attorney
to transfer said Note on the books of the within named Company with full power of substitution in the premises.

Dated:                                         

NOTICE: The signature to this assignment must correspond with the name as it appears on the first page of the within Note in every particular, without alteration or enlargement or any change whatever.

[FORM OF EXCHANGE NOTICE]

To: ARCHSTONE-SMITH OPERATING TRUST

     The undersigned registered owner of this Note hereby exercises the option to exchange this Note, or the portion hereof (which is $1,000 principal amount or an integral multiple thereof) below designated, into cash, Common Shares or a combination thereof, in accordance with the terms of the Indenture referred to in this Note, and directs that the shares issuable and deliverable upon such exchange, if any, together with any check in payment of the cash in respect of the remaining Exchange Obligation (as defined in the Indenture) and for fractional shares and any Notes representing any unexchanged principal amount hereof, be issued and delivered to the registered holder hereof unless a different name has been indicated below. If shares or any portion of this Note not exchanged are to be issued in the name of a person other than the undersigned, the undersigned will pay all transfer taxes payable with respect thereto. Any amount required to be paid to the undersigned on account of interest accompanies this Note.

Dated:
	Signature(s)
Signature Guarantee
Signature(s) must be guaranteed by an eligible guarantor institution (banks, stock brokers, savings and loan associations and credit unions) with membership in an approved signature guarantee medallion program pursuant to Rule 17Ad-15 under the Securities Exchange Act of 1934, as amended, if Common Shares are to be issued, or Notes to be delivered, other than to and in the name of the registered holder.

Fill in for registration of shares if to be issued, and Notes if to be delivered, other than to and in the name of the registered holder:
(Name)
(Street Address)
(City, State and Zip Code)
Please print name and address
	Principal amount to be exchanged (if less than all): $_____ ,000
	Social Security or Other Taxpayer Identification Number

[FORM OF PUT RIGHT REPURCHASE NOTICE]

     To: ARCHSTONE-SMITH OPERATING TRUST

     The undersigned hereby requests and instructs Archstone-Smith Operating Trust to repay the entire principal amount of this Note, or a portion hereof (which is $1,000 principal amount or an integral multiple thereof) below designated, on July ___, ___ in accordance with the terms of this Indenture referred to in this Note at the Put Right Repurchase Price, to the registered Holder hereof.

Dated:
	Signature(s)
	Social Security or Other Taxpayer Identification Number Principal amount to be repaid (if less than all): $___,000 NOTICE: The above signatures of the Holder(s) hereof must correspond with the name as written upon the face of the Note in every particular without alteration or enlargement or any change whatever.

[FORM OF FUNDAMENTAL CHANGE REPURCHASE NOTICE]

     To: ARCHSTONE-SMITH OPERATING TRUST

     The undersigned registered owner of this Note hereby acknowledges receipt of a notice from Archstone-Smith Operating Trust (the “Company”) as to the occurrence of a Fundamental Change with respect to the Company and requests and instructs the Company to repay the entire principal amount of this Note, or the portion thereof (which is $1,000 principal amount or an integral multiple thereof) below designated, in accordance with the terms of this Indenture referred to in this Note, to the registered Holder hereof.

Dated:
	Signature(s)
	Social Security or Other Taxpayer Identification Number Principal amount to be repaid (if less than all): $___,000 NOTICE: The above signatures of the Holder(s) hereof must correspond with the name as written upon the face of the Note in every particular without alteration or enlargement or any change whatever.

EX-5.1

Exhibit 5.1

July 14, 2006	Mayer, Brown, Rowe & Maw LLP
	71 South Wacker Drive
	Chicago, Illinois 60606-4637
	Main Tel (312) 782-0600
	Main Fax (312) 701-7711
Archstone-Smith Operating Trust	www.mayerbrownrowe.com
9200 East Panorama Circle, Suite 400
Englewood, Colorado 80112

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

     We have acted as special counsel to Archstone-Smith Operating Trust, a Maryland real estate investment trust (“Archstone”), in connection with (i) an offering pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”), of Archstone’s Debt Securities, and the corporate proceedings taken in connection therewith and (ii) the issuance of $500 million aggregate principal amount of 4.00% Exchangeable Senior Notes due 2036 and (the “Notes”). The Notes are to be issued (1) under the Indenture dated as of February 1, 1994, between Archstone and Morgan Guaranty Trust Company of New York, as trustee (“Morgan”), as supplemented by the First Supplemental Indenture dated as of February 2, 1994, between Archstone, Morgan and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as successor trustee (the “Trustee”), as further supplemented by the Second Supplemental Indenture dated as of August 2, 2004, between Archstone and the Trustee, and as further supplemented by the Third Supplemental Indenture dated as of July 14, 2006, between Archstone and the Trustee (the “Third Supplemental Indenture”) (collectively, the “Indenture”), and (2) subject to an Underwriting Agreement, dated July 11, 2006 (the “Underwriting Agreement”), among Archstone, Archstone-Smith Trust, Citigroup Global Markets Inc. and Morgan Stanley & Co. Incorporated, as representatives of the several underwriters named in the Underwriting Agreement.

     We have also participated in the preparation and filing with the Securities and Exchange Commission under the Securities Act of a Registration Statement on Form S-3, as amended (File No. 333-133285) (the “Registration Statement”), relating to the debt securities of which the Notes are a part. In rendering our opinions set forth below, we have examined originals or copies identified to our satisfaction of (i) the Underwriting Agreement; (ii) the Registration Statement; (iii) the prospectus as supplemented relating to the Notes; (iv) the Indenture; (v) the form of the Notes; and (vi) the Third Supplemental Indenture. The Notes are registered on Registration Statement No. 333-133285. In addition, we have examined and relied upon other documents, certificates, corporate records, opinions and instruments, obtained from Archstone or

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Mayer, Brown, Rowe & Maw LLP operates in combination with our associated English limited liability partnership in the offices listed above.

MAYER, BROWN, ROWE & MAW LLP

July 14, 2006
Page 2

other sources believed by us to be reliable, as we have deemed necessary or appropriate for the purpose of this opinion.

     As special counsel to Archstone, we have examined originals or copies certified or otherwise identified to our satisfaction of the Declaration of Trust, Archstone’s Amended and Restated Bylaws, as amended, resolutions of the sole Trustee of Archstone and such Archstone records, certificates and other documents and such questions of law as we considered necessary or appropriate for the purpose of this opinion. As to certain facts material to our opinion, we have relied, to the extent we deem such reliance proper, upon certificates of public officials and officers of Archstone. In rendering this opinion, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals and the conformity to authentic original documents of all documents submitted to us as copies.

     Based upon and subject to the foregoing and to the assumptions, conditions and limitations set forth herein, and assuming that the Notes are issued in accordance with the terms of the Underwriting Agreement, we are of the opinion that the Notes constitute valid and legally binding obligations of Archstone entitled to the benefits of the Indenture, except that (a) the enforceability thereof may be subject to (i) bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance or other similar laws now or hereafter in effect relating to or affecting creditors’ rights or remedies generally and (ii) general principles of equity and to the discretion of the court before which any proceedings therefor may be brought (regardless of whether enforcement is sought in a proceeding at law or in equity) and (b) the enforceability of provisions imposing liquidated damages, penalties or an increase in interest rate upon the occurrence of certain events may be limited in certain circumstances ((a) and (b), collectively, the “Enforceability Exceptions”).

     We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to being named in the related prospectus and any related prospectus supplement under the caption “Legal Matters” with respect to the matters stated therein.

     We are admitted to practice law in the State of Illinois, and we express no opinion as to matters under or involving any laws other than the laws of the State of Illinois, the laws of the State of New York, the federal laws of the United States of America and the laws of the State of Maryland.

Sincerely,

/s/ MAYER, BROWN, ROWE & MAW LLP

EX-8.1

Exhibit 8.1

July 14, 2006	Mayer, Brown, Rowe & Maw LLP 71 South Wacker Drive Chicago, Illinois 60606-4637
	Main Tel (312) 782-0600 Main Fax (312) 701-7711 www.mayerbrownrowe.com

Archstone-Smith Trust
9200 East Panorama Circle, Suite 400
Englewood, Colorado 80112

Re: Status of Archstone-Smith Trust as a Real Estate
Investment Trust; Information in the Registration
Statement under the heading “Federal Income Tax
Considerations Relating to Archstone-Smith”

Ladies and Gentlemen:

     In connection with the filing of a Registration Statement on Form S-3 with the Securities and Exchange Commission on the date hereof (the “Registration Statement”) by Archstone-Smith Operating Trust, a Maryland real estate investment trust,¹ you have requested our opinions concerning (i) the qualification and taxation of Archstone-Smith Trust, a Maryland real estate investment trust (“Archstone-Smith”), as a real estate investment trust (“REIT”) and (ii) the information in the Registration Statement under the heading “Certain U.S. Federal Income Tax Considerations.”

     In formulating our opinions, we have reviewed and relied upon the Registration Statement, such other documents and information provided by you, and such applicable provisions of law as we have considered necessary or desirable for purposes of the opinions expressed herein.

     In addition, we have relied upon certain representations made by Archstone-Smith relating to the organization and actual and proposed operation of Archstone-Smith and its relevant subsidiaries. For purposes of our opinions, we have not made an independent investigation of the facts set forth in such documents, representations from Archstone-Smith or the Registration Statement. We have, consequently, relied upon your representations that the information presented in such documents, or otherwise furnished to us, accurately and completely describes all material facts. We have also relied upon the opinion of Hogan & Hartson L.L.P., dated October 31, 2001, with respect to the qualification as a real estate investment trust for U.S. federal income tax purposes of Charles E. Smith Residential Realty, Inc., a Maryland corporation, commencing with its taxable year ended December 31, 1994.

¹ Unless otherwise specifically defined herein, all capitalized terms have the meaning assigned to them in the Registration Statement.

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Independent Mexico City Correspondent: Jauregui, Navarrete y Nader S.C.

Mayer, Brown, Rowe & Maw LLP operates in combination with our associated English limited liability partnership in the offices listed above.

Archstone-Smith Trust
July 14, 2006
Page 2

     Our opinions expressed herein are based on the applicable laws of the State of Maryland, the Code, Treasury regulations promulgated thereunder, and the interpretations of the Code and such regulations by the courts and the Internal Revenue Service, all as they are in effect and exist at the date of this letter. It should be noted that statutes, regulations, judicial decisions and administrative interpretations are subject to change at any time and, in some circumstances, with retroactive effect. A material change that is made after the date hereof in any of the foregoing bases for our opinions could adversely affect our conclusions.

     Based upon and subject to the foregoing, it is our opinion that:

     1. Beginning with Archstone-Smith’s taxable year ending on December 31, 2001, Archstone-Smith has been organized in conformity with the requirements for qualification as a REIT under the Code, and Archstone-Smith’s actual and proposed method of operation, as described in the Registration Statement and as represented by Archstone-Smith, has enabled it and will continue to enable it to satisfy the requirements for qualification as a REIT.

     2. The information in the Registration Statement under the heading “Certain U.S. Federal Income Tax Considerations” to the extent that it constitutes matters of law or legal conclusions, has been reviewed by us and is correct in all material respects.

     Other than as expressly stated above, we express no opinion on any issue relating to Archstone-Smith or to any investment therein.

     We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the use of the name of our firm therein.

Very truly yours,

/s/ Mayer, Brown, Rowe & Maw LLP

EX-10.1

Exhibit 10.1

REGISTRATION RIGHTS AGREEMENT

by and among

ARCHSTONE-SMITH TRUST

and

ARCHSTONE-SMITH OPERATING TRUST

Dated: July 14, 2006

REGISTRATION RIGHTS AND LOCK-UP AGREEMENT

     This Registration Rights Agreement (this “Agreement”) is entered into as of July 14, 2006 by and among Archstone-Smith Trust, a Maryland real estate investment trust (the “Trust”), and Archstone-Smith Operating Trust, a Maryland real estate investment trust (the “Company”), for itself and for the benefit of the Holders (as hereinafter defined).

     WHEREAS, pursuant to the terms of the Third Supplemental Indenture dated as of July 14, 2006 to the indenture dated as of February 1, 1994, as supplemented by the First Supplemental Indenture, dated as of February 2, 1994, and the Second Supplemental Indenture, dated as of August 2, 2004, between the Company and the U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as trustee (the “Indenture”) pursuant to which the Company issued $575,000,000 principal amount of its 4.00% Exchangeable Senior Notes due 2036 (the “Notes”), as an inducement for the Holders to purchase Notes, the Trust hereby grants certain registration rights to the Company for the benefit of the Holders with respect to common shares of beneficial interest, par value $0.01 per share (the “Common Shares”), of the Trust that may in the future be issued to the Holders by the Trust on account of Notes, if such Common Shares when so issued are “restricted securities” under the Securities Act of 1933, as amended (“Restricted Shares”), consisting of either (1) Restricted Shares delivered to the Holders by the Company pursuant to the Indenture on account of Notes, or (2) Restricted Shares issued by the Trust upon conversion into Common Shares of Units (as hereinafter defined) issued by the Company to the Holders pursuant to the Indenture on account of Notes, whether by exercise by the Holders of a redemption right or otherwise pursuant to the Company Agreement;

     NOW, THEREFORE, in consideration of the foregoing, the mutual promises and agreements set forth herein, and other valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows:

     1. Certain Definitions

     As used in this Agreement, in addition to the other terms defined herein, the following capitalized defined terms shall have the following meanings:

     “Affiliate” shall mean a Person that directly, or indirectly though one or more intermediaries, controls, is controlled by, or is under common control with a specified Person.

     “Common Shares” shall have the meaning set forth in the preamble to this Agreement.

     “Company” shall have the meaning set forth in the preamble to this Agreement.

     “Company Offering” shall have the meaning set forth in Section 8(c) hereof.

     “Demand Registration” shall have the meaning set forth in Section 2(b) hereof.

     “Exchange Act” shall mean the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.

     “Fair Market Value” shall mean the closing sales price, or the closing sales bid if no sales were reported, of the Common Shares as quoted on the NYSE or such other national securities exchange on which the Common Shares are listed on the date immediately preceding the date of calculation or if there are no sales or bids for such date, then for the last preceding business day for such sales or bids, as reported in The Wall Street Journal or similar publication.

     “Filing Date” shall have the meaning set forth in Section 2(a) hereof.

     “Holder” or “Holders” shall mean the beneficial owners from time to time of the Notes and the beneficial owners from time to time of the Restricted Shares or Restricted Units issued on account of Notes pursuant to the Indenture.

     “Indemnitee” shall have the meaning set forth in Section 6 hereof.

     “Indenture” shall have the meaning set forth in the preamble to this Agreement.

     “NASD” shall mean the National Association of Securities Dealers, Inc.

     “Notes” shall have the meaning set forth in the preamble to this Agreement.

     “NYSE” shall mean the New York Stock Exchange.

     “Notice Holder” shall mean, on any date, any Holder that has delivered to the Trust on or prior to such date a duly executed and completed Notice and Questionnaire.

     “Notice and Questionnaire” shall mean a written notice and questionnaire containing all material information required to be disclosed with respect to such Holder as a “selling stockholder” in a Resale Shelf Registration Statement under the Securities Act.

     “Offering Blackout Period” shall have the meaning set forth in Section 8(c) hereof.

     “Partnership” shall have the meaning set forth in the recitals to this Agreement.

     “Partnership Agreement” shall mean the agreement of limited partnership of BPLP, as amended from time to time.

     “Person” shall mean an individual, partnership, corporation, trust, or unincorporated organization, or a government or agency or political subdivision thereof.

     “Prospectus” shall mean the prospectus included in a Registration Statement, including any preliminary prospectus, as amended or supplemented by any prospectus supplement with respect to the terms of the offering of any portion of the Registrable Shares covered by such Registration Statement, and by all other amendments and supplements to such prospectus, including post-effective amendments, and in each case including all material incorporated by reference therein.

     “Registrable Shares” (a) when used with respect to any Holder, shall mean all Shares of such Holder, until (A) the earliest of (i) their effective registration under the Securities Act and

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resale in accordance with the Registration Statement covering them, (ii) expiration of the holding period that would be applicable thereto under Rule 144(k) or any successor provision, (iii) their sale to the public pursuant to Rule 144 under the Securities Act, or (iv) the date such Shares cease to be outstanding (whether as a result of redemption, repurchase and cancellation, conversion or otherwise), and (B) as a result of the event or circumstance described in any of the foregoing clauses (A)(i) through (A)(iii), the legend with respect to transfer restrictions required under the Securities Act is removed or removable. For clarification, it is understood that Common Shares issued to a Holder pursuant to the Indenture which are not Restricted Shares are not Registrable Shares, and, accordingly, neither a Holder nor any subsequent holder (whether or not such holder is an Affiliate of the Trust) of such Common Shares shall have any registration rights with respect to such Common Shares under this Agreement.

     “Registration Expenses” shall mean any and all expenses incident to the performance of or compliance with this Agreement, including without limitation: (i) all registration and filing fees; (ii) all fees and expenses associated with a required listing of the Registrable Shares on any securities exchange; (iii) fees and expenses with respect to filings required to be made with the NYSE or the NASD; (iv) fees and expenses of compliance with securities or “blue sky” laws; (v) printing expenses, messenger, telephone and delivery expenses; (vi) fees and disbursements of counsel for the Trust and customary fees and expenses for independent certified public accountants retained by the Trust (including the expenses of any comfort letters or costs associated with the delivery by independent certified public accountants of a comfort letter or comfort letters); (vii) securities acts liability insurance, if the Trust so desires; (viii) all internal expenses of the Trust (including, without limitation, all salaries and expenses of its officers and employees performing legal or accounting duties); (ix) the expense of any annual audit; and (x) the fees and expenses of any person, including special experts, retained by the Trust; provided, however, that Registration Expenses shall not include, and the Trust shall not have any obligation to pay, any underwriting fees, discounts, or commissions attributable to the sale of such Registrable Shares, or any legal fees and expenses of counsel to any Holder and any broker/dealer or other financial intermediary or agent engaged by any Holder.

     “Registration Statement” shall mean any registration statement of the Trust which covers the resale of any of the Registrable Shares under the Securities Act on an appropriate form, and all amendments and supplements to such registration statement, including post-effective amendments, in each case including the Prospectus contained therein, all exhibits thereto and all materials incorporated by reference therein.

     “Resale Shelf Registration Expiration Date” shall have the meaning set forth in Section 2(a) hereof.

     “Resale Shelf Registration Statement” shall have the meaning set forth in Section 2(a) hereof.

     “Restricted Shares” shall have the meaning set forth in the preamble to this Agreement.

     “Rule 144” means Rule 144 under the Securities Act (or any successor provision).

     “SEC” shall mean the Securities and Exchange Commission.

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     “Securities Act” shall mean the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.

     “Shares” shall mean all Restricted Shares issued to all Holders as described in the preamble to this Agreement and any other Common Shares issued as a dividend with respect to, or in exchange for or in replacement of such Restricted Shares.

     “Suspension Event” shall have the meaning set forth in Section 8(b) hereof.

     “Trustee” shall have the meaning set forth in the preamble to this Agreement.

     “Units” shall mean the Class A-1 common units of beneficial interests, par value $0.01 per unit, of the Company issued by the Company to the Holders pursuant to the Indenture (or any other interests issued on account of those units as a result of a unit split, combination, distribution or other similar recapitalization event applying to all such units).

     2. Registration

          (a) Resale Shelf Registration Statement. Subject to the provisions of Section 2(b) below, the Trust shall prepare and file with the SEC a Registration Statement (a “Resale Shelf Registration Statement”) for an offering to be made on a delayed or continuous basis pursuant to Rule 415 under the Securities Act relating to the sale by the Holders from time to time of their Registrable Shares, such filing to be made on a date (the “Filing Date”) which is no later than thirty (30) days after the issuance of the Registrable Shares covered by such Registration Statement. The Trust shall use its reasonable efforts to cause such Resale Shelf Registration Statement to be declared effective by the SEC as soon as practicable after the Filing Date. The Trust agrees to use its reasonable efforts to keep the Resale Shelf Registration Statement, after its date of effectiveness, continuously effective until the date (the “Resale Shelf Registration Expiration Date”) that all registrable Shares have ceased to be Registrable Shares. At the time the initial Resale Shelf Registration Statement is declared effective, each Holder that became a Notice Holder on or prior to the date ten (10) business days prior to such time of effectiveness shall be named as a selling securityholder in the initial Resale Shelf Registration Statement and the related Prospectus in such a manner as to permit such Holder to deliver such Prospectus to purchasers of Registrable Securities in accordance with applicable law. No holder shall be entitled to be named as a selling securityholder in the initial Resale Shelf Registration Statement or to use the Prospectus forming a part thereof for offers or resales of Registrable Securities unless such holder is a Notice Holder on or prior to the date ten (10) business days prior to such time of effectiveness. Each Holder agrees that if such Holder wishes to sell Registrable Shares pursuant to a Resale Shelf Registration Statement and related Prospectus, it will do so only in accordance with this Section 2(a). Following the date that the initial Resale Shelf Registration Statement is declared effective, each Holder that is not a Notice Holder wishing to sell Registrable Shares pursuant to a Resale Shelf Registration Statement and related Prospectus agrees to deliver a Notice and Questionnaire to the Trust at least fifteen (15) business days prior to any intended distribution of Registrable Shares under the Resale Shelf Registration Statement. From and after the date the initial Resale Shelf Registration Statement is declared effective, the Trust shall, as promptly as reasonably practicable after the date a Notice and Questionnaire is delivered, and in any event upon fifteen (15) business days after such date:

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     (i) if required by applicable law, file with the SEC a post-effective amendment to the Resale Shelf Registration Statement or prepare and, if required by applicable law, file a supplement to the related Prospectus or a supplement or amendment to any document incorporated therein by reference or file any other required document so that the Holder delivering such Notice and Questionnaire is named as a selling stockholder in the Resale Shelf Registration Statement and the related Prospectus in such a manner as to permit such Holder to deliver such Prospectus to purchasers of the Registrable Shares in accordance with the Securities Act and, if the Trust shall file a post-effective amendment to the Resale Shelf Registration Statement, use its reasonable efforts to cause such post-effective amendment to be declared effective under the Securities Act as promptly as is reasonably practicable, but in any event by the date that is forty-five (45) days after the date such post-effective amendment is required by this clause to be filed; and

     (ii) provide such Holder copies of any documents filed pursuant to this Section 2(a) notify such Holder as promptly as practicable after the effectiveness under the Securities Act of any post-effective amendment filed pursuant to Section 2(a);

Notwithstanding anything contained herein to the contrary, (i) the Trust shall be under no obligation to name any Holder that is not a Notice Holder as a selling stockholder in any Registration Statement or related Prospectus.

          (b) Demand Registration. At any time any Registrable Shares are outstanding and a Registration Statement covering the sale of such Registrable Shares is not effective, the Trust shall, at the written request of any Holder or Holders (a “Demand Notice”), cause to be filed as soon as practicable after the date of such request by such Holder a Registration Statement in accordance with Rule 415 under the Securities Act (or such other rule as is applicable to the proposed sale) relating to the sale by such Holder of all or a portion of the Registrable Shares held by such Holder in accordance with the terms hereof, and shall use reasonable efforts to cause such Registration Statement to be declared effective by the SEC as soon as practicable thereafter (a “Demand Registration”); provided, however, that the Trust shall not be required to file such Registration Statement unless the number of Registrable Shares included in such Demand Notice have a Fair Market Value in excess of $1,000,000. The Trust agrees to use its reasonable efforts to keep the Demand Registration continuously effective, after its date of effectiveness, with respect to the Registrable Shares of the requesting Holder or Holders until the earlier of (a) the date on which such Holder no longer holds any Registrable Shares or (b) the date on which all of the Registrable Shares held by such Holder have become eligible for sale pursuant to Rule 144(k) (or any successor provision).

          (c) Notification and Distribution of Materials. The Trust shall notify the Holder of the effectiveness of any Registration Statement applicable to the Registrable Shares and shall furnish to the Holders, without charge, such number of copies of the Registration Statement (including any amendments, supplements and exhibits), the Prospectus contained therein (including each preliminary prospectus and all related amendments and supplements) and any documents incorporated by reference in the Registration Statement or such other documents as the Holders may reasonably request in order to facilitate the sale of the Registrable Shares in the manner described in the Registration Statement.

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          (d) Amendments and Supplements. The Trust shall promptly prepare and file with the SEC from time to time such amendments and supplements to the Registration Statement and Prospectus used in connection therewith as may be necessary to keep the Registration Statement effective and to comply with the provisions of the Securities Act with respect to the disposition of all the Registrable Shares until the earlier of (a) such time as all of the Registrable Shares have been issued or disposed of in accordance with the intended methods of disposition by the Holders or issuance by the Trust as set forth in the Registration Statement or (b) the date on which the Registration Statement is no longer required to be effective under the terms of this Agreement. Upon ten (10) business days’ notice, the Trust shall file any supplement or post-effective amendment to the Registration Statement with respect to the plan of distribution or a Holder’s ownership interests in its Registrable Shares that is reasonably necessary to permit the sale of such Holder’s Registrable Shares pursuant to the Registration Statement.

          (e) Notice of Certain Events. The Trust shall promptly notify the Holders of, and confirm in writing, any request by the SEC for any amendment or supplement to, or additional information in connection with, any Registration Statement required to be prepared and filed hereunder (or Prospectus relating thereto). The Trust shall promptly notify each Holder of, and confirm in writing, the filing of the Registration Statement or any Prospectus, amendment or supplement related thereto or any post-effective amendment to the Registration Statement and the effectiveness of any post-effective amendment.

     At any time when a Prospectus relating to the Registration Statement is required to be delivered under the Securities Act by a Holder to a transferee, the Trust shall immediately notify the Holders of the happening of any event as a result of which the Prospectus included in such Registration Statement, as then in effect, includes an untrue statement of a material fact or omits to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading. In such event, the Trust shall promptly, and in any event within ten (10) business days, prepare and furnish to the Holders a reasonable number of copies of a supplement to or an amendment of such Prospectus as may be necessary so that, as thereafter delivered to the purchasers of Registrable Shares sold under the Prospectus, such Prospectus shall not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they are made, not misleading. The Trust shall, if necessary, promptly, and in any event within ten (10) business days, amend the Registration Statement of which such Prospectus is a part to reflect such amendment or supplement.

     3. State Securities Laws. Subject to the conditions set forth in this Agreement, the Trust shall, in connection with the filing of any Registration Statement hereunder, file such documents as may be necessary to register or qualify the Registrable Shares under the securities or “Blue Sky” laws of such states as the Holders may reasonably request, and the Trust shall use its reasonable efforts to cause such filings to become effective in a timely manner; provided, however, that the Trust shall not be obligated to qualify as a foreign corporation to do business under the laws of any such state in which it is not then qualified or to file any general consent to service of process in any such state. Once effective, the Trust shall use its reasonable efforts to keep such filings effective until the earlier of (a) such time as all of the Registrable Shares have been disposed of in accordance with the intended methods of disposition by the Holders as set

6

forth in the applicable Registration Statement, (b) in the case of a particular state, the applicable Holders have notified the Trust that they no longer require an effective filing in such state in accordance with their original request for filing or (c) the date on which the applicable Registration Statement ceases to be effective.

     4. Listing. The Trust will use reasonable efforts to cause all Registrable Shares to be listed or otherwise eligible for full trading privileges on the principal national securities exchange (currently the NYSE) on which the Common Shares are then listed, in each case not later than the date on which a Registration Statement covering the Registrable Shares becomes effective or the Registrable Shares are issued by the Trust to a Holder, whichever is later. The Trust will use reasonable efforts to continue the listing or trading privilege for all Registrable Shares on such exchange. The Trust will promptly notify the Holders of, and confirm in writing, the delisting of the Common Shares by such exchange.

     5. Expenses. The Trust shall bear all Registration Expenses incurred in connection with the registration of the Registrable Shares pursuant to this Agreement and the Trust’s performance of its other obligations under the terms of this Agreement. The Holders shall bear all underwriting fees, discounts or commissions attributable to the sale of securities by the Holders, or any legal fees and expenses of counsel to the Holders and any broker/dealer or other financial intermediary or agent engaged by Holders and all other expenses incurred in connection with the performance by the Holders of their obligations under the terms of this Agreement.

     6. Indemnification

          (a) Indemnification by the Trust. The Trust shall indemnify and hold harmless each Holder and each Person, if any, who controls such Holder (within the meaning of Section 15 of the Securities Act) as follows:

          (i) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Resale Shelf Registration Statement (or any amendment thereto) pursuant to which the Registrable Shares were registered under the Securities Act, including all documents incorporated therein by reference, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact contained in any Prospectus (or any amendment or supplement thereto), including all documents incorporated therein by reference, or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

          (ii) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, if such settlement is effected with the written consent of the Trust; and

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          (iii) against any and all expense whatsoever, as incurred (including reasonable fees and disbursements of counsel), reasonably incurred in investigating, preparing or defending against any litigation, or investigation or proceeding by any governmental agency or body, commenced or threatened, in each case whether or not a party, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under subparagraph (i) or (ii) above;

provided, however, that the indemnity provided pursuant to this Section 6(a) does not apply to the Holder with respect to any loss, liability, claim, damage or expense to the extent arising out of (x) any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Trust by the Holder expressly for use in the Resale Shelf Registration Statement (or any amendment thereto) or any Prospectus (or any amendment or supplement thereto) or (y) the Holder’s failure to deliver an amended or supplemental Prospectus that was timely delivered to the Holder by the Trust if such loss, liability, claim, damage or expense would not have arisen had such delivery by the Holder occurred.

          (b) Indemnification by the Holders. In connection with the Resale Shelf Registration Statement, each Holder, on a several and not joint basis, shall indemnify and hold harmless the Trust, and each of its trustees and officers (including each trustee and officer of the Trust who signed the Resale Shelf Registration Statement), and each Person, if any, who controls the Trust within the meaning of Section 15 of the Securities Act, to the same extent as the indemnity contained in Section 6(a) (except that any settlement described in Section 6(a)(ii) shall be effected with the written consent of the Holder), but only insofar as such loss, liability, claim, damage or expense arises out of or is based upon any untrue statement or omission, or alleged untrue statements or omissions, made in the Resale Shelf Registration Statement (or any amendment thereto) or any Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information furnished to the Trust by the Holder expressly for use in such Resale Shelf Registration Statement (or any amendment thereto) or such Prospectus (or any amendment or supplement thereto). Notwithstanding the provisions of this Section 6(b), the Holder shall not be required to indemnify the Trust with respect to any amount in excess of the amount of the total net proceeds received by the Holder from sales of the Registrable Shares under the Resale Shelf Registration Statement.

     7. Indemnification Procedures The indemnified party shall give reasonably prompt notice to the indemnifying party of any action or proceeding commenced against it of which the indemnified party has actual knowledge and in respect of which indemnity may be sought hereunder, but failure to so notify the indemnifying party (i) shall not relieve it from any liability which it may have under the indemnity agreement provided in Section 6(a) or 6(b), unless and to the extent it did not otherwise learn of such action and the lack of notice by the indemnified party results in the forfeiture by the indemnifying party of substantial rights and defenses and (ii) shall not, in any event, relieve the indemnifying party from any obligations to the indemnified party other than the indemnification obligation provided under Section 6(a) or 6(b). If the indemnifying party so elects within a reasonable time after receipt of such notice, the indemnifying party may assume the defense of such action or proceeding at such indemnifying party’s own expense with counsel chosen by the indemnifying party and approved by the

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indemnified party, which approval shall not be unreasonably withheld; provided, however, that, if the indemnified party reasonably determines that a conflict of interest exists where it is advisable for the indemnified party to be represented by separate counsel or that, upon advice of counsel, there may be legal defenses available to it which are different from or in addition to those available to the indemnifying party, then the indemnifying party shall not be entitled to assume such defense and the indemnified party shall be entitled to separate counsel at the indemnifying party’s expense. If the indemnifying party is not entitled to assume the defense of such action or proceeding as a result of the proviso to the preceding sentence, the indemnifying party’s counsel shall be entitled to conduct the indemnifying party’s defense and counsel for the indemnified party shall be entitled to conduct the defense of the indemnified party, it being understood that both such counsel will cooperate with each other to conduct the defense of such action or proceeding as efficiently as possible; provided, however, that counsel for the indemnified party shall not be required to take any action which would prejudice the defense of the indemnified party. If the indemnifying party is not so entitled to assume the defense of such action or does not assume such defense, after having received the notice referred to in the first sentence of this paragraph, the indemnifying party shall pay the reasonable fees and expenses of counsel for the indemnified party. In such event, however, the indemnifying party shall not be liable for any settlement effected without the written consent of the indemnifying party. If an indemnifying party is entitled to assume, and assumes, the defense of such action or proceeding in accordance with this paragraph, the indemnifying party shall not be liable for any fees and expenses of counsel for the indemnified party incurred thereafter in connection with such action or proceeding.

     8. Suspension of Registration Requirement; Restriction on Sales.

          (a) The Trust shall promptly notify each Holder of, and confirm in writing, the issuance by the SEC of any stop order suspending the effectiveness of a Registration Statement with respect to such Holder’s Registrable Shares or the initiation of any proceedings for that purpose. The Trust shall use its reasonable efforts to obtain the withdrawal of any order suspending the effectiveness of such a Registration Statement at the earliest possible moment and in any event within forty-five (45) days from the initial date of such suspension.

          (b) Notwithstanding anything to the contrary set forth in this Agreement, the Trust’s obligation under this Agreement to file, amend or supplement a Registration Statement, or to cause a Registration Statement, or any filings with any state securities commission, to become effective shall be suspended, for one or more periods not to exceed the period described in Section 9 below, in the event of pending negotiations relating to, or consummation of, a transaction or the occurrence of an event that (i) would require additional disclosure of material information by the Trust in the Registration Statement or such filing, as to which the Trust has a bona fide business purpose for preserving confidentiality, or (ii) render the Trust unable to comply with SEC requirements, or (iii) would otherwise make it impractical or unadvisable to cause the Registration Statement or such filings to be filed, amended or supplemented or to become effective (any such circumstances being hereinafter referred to as a “Suspension Event”). The Trust shall notify the Holders of the existence of any Suspension Event by promptly delivering to each Holder a certificate signed by an executive officer of the Trust stating that a Suspension Event has occurred and is continuing.

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          (c) Subject to the terms of Section 9 below, each Holder of Registrable Shares agrees, if requested by the Trust in the case of a Company-initiated non-underwritten offering registered under the Securities Act or if requested by the managing underwriter or underwriters in a Company-initiated underwritten offering (each, a “Company Offering”), not to effect any public sale or distribution of any of the Shares during the period (the “Offering Blackout Period”) beginning upon receipt by such Holder of written notice from the Trust, but in any event no earlier than the fifteenth (15th) day preceding the anticipated date of pricing of such Company Offering, and ending on the earlier to occur of:

          (i) ninety (90) days after the closing date of such Company Offering;

          (ii) thirty (30) days after the date on which the closing price of the class of equity securities sold by the Trust in such Company Offering shall have averaged for a period of twenty (20) consecutive trading days at least one-hundred-five percent (105%) of the initial price to the public of such security in such Company Offering;

          (iii) the date on which the Trust may begin to effect any public sale or distribution of any of the securities of the Trust following such Company Offering pursuant to any contractual lock-up or similar restrictions on the sale of Common Shares;

          (iv) the date on which all directors and executive officers who have been required to enter into contractual lock-up or similar restrictions on the sale of Common Shares owned by them may begin to effect public sales of Common Shares following such Company Offering, including pursuant to waivers of the restrictions by the managing underwriter or underwriters; or

          (v) the date the Trust or managing underwriter or underwriters withdraws such request in writing;

provided, however, that this Section 8(c) shall not prohibit resales of Shares by any Holder not subject to the registration requirements of the Securities Act (including, without limitation resale of Shares pursuant to Rule 144) and similarly exempt from any registration requirement under any state “Blue Sky” or similar laws; provided, that the purchaser in any such private resale shall agree in writing to be subject to such restrictions for the remaining portion of such period that would otherwise apply to such Holder.

          (d) Subject to the terms of Section 9 below, each Holder agrees that, following the effectiveness of any Registration Statement relating to Registrable Shares of such Holder, such Holder will not effect any sales of the Shares pursuant to such Registration Statement or any filings with any state Securities Commission at any time after such Holder has received notice from the Trust to suspend sales as a result of the occurrence or existence of any Suspension Event or so that the Trust may correct or update the Registration Statement or such filing. The Holders may recommence effecting sales of the Registrable Shares pursuant to the Registration Statement or such filings, and all other obligations which are suspended as a result of a Suspension Event shall no longer be so suspended, following further notice to such effect from the Trust, which notice shall be given by the Trust not later than one (1) business day after the conclusion of any such Suspension Event.

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     9. Limitations on Suspension/Blackout Periods. Notwithstanding anything herein to the contrary, the Trust covenants and agrees that (i) the Trust’s rights to suspend its obligation under this Agreement to file, amend or supplement a Registration Statement and maintain the effectiveness of any Registration Statement during the pendency of any Suspension Event, (ii) the Holders’ obligation to suspend public sales of Shares during one or more Offering Blackout Periods and (iii) the Holders’ obligations to suspend sales of Shares pursuant to a Registration Statement during the pendency of any Suspension Event, shall not, in the aggregate, cause the Holders to be required to suspend sales of Shares or relieve the Trust of its obligation to file, amend or supplement and maintain the effectiveness of a Registration Statement for longer than ninety (90) days during any twelve (12) month period.

     10. Additional Shares. The Trust, at its option, may register, under any Registration Statement and any filings with any state securities commissions filed pursuant to this Agreement, any number of unissued, treasury or other Common Shares of or owned by the Trust and any of its Subsidiaries or any Common Shares or other securities of the Trust owned by any other security holder or security holders of the Trust.

     11. Contribution. If the indemnification provided for in Section 6 is unavailable to an indemnified party with respect to any losses, claims, damages, actions, liabilities, costs or expenses referred to therein or is insufficient to hold the indemnified party harmless as contemplated therein, then the indemnifying party, in lieu of indemnifying such indemnified party, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages, actions, liabilities, costs or expenses in such proportion as is appropriate to reflect the relative fault of the indemnifying party, on the one hand, and the indemnified party, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, actions, liabilities, costs or expenses as well as any other relevant equitable considerations. The relative fault of the indemnifying party, on the one hand, and of the indemnified party, on the other hand, shall be determined by reference to, among other factors, whether the untrue or alleged untrue statement of a material fact or omission to state a material fact relates to information supplied by the indemnifying party or by the indemnified party and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission; provided, however, that in no event shall the obligation of any indemnifying party to contribute under this Section 11 exceed the amount that such indemnifying party would have been obligated to pay by way of indemnification if the indemnification provided for under Section 6 hereof had been available under the circumstances.

     The Trust and the Holders agree that it would not be just and equitable if contribution pursuant to this Section 11 were determined by pro rata allocation or by any other method of allocation that does not take account of the equitable considerations referred to in the immediately preceding paragraph.

     Notwithstanding the provisions of this Section 11, no Holder shall be required to contribute any amount in excess of the amount by which the gross proceeds from the sale of Shares exceeds the amount of any damages that such Holder has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission. No indemnified party guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be

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entitled to contribution from any indemnifying party who was not guilty of such fraudulent misrepresentation.

     12. No Other Obligation to Register. Except as otherwise expressly provided in this Agreement, the Trust shall have no obligation to the Holders to register the Registrable Shares under the Securities Act.

     13. Amendments and Waivers. The provisions of this Agreement, including the provisions of this sentence, may not be amended, modified or supplemented, and waivers or consents to departures from the provisions hereof may not be given, unless the Trust has obtained the written consent of Holders of a majority of the then outstanding Registrable Shares (with Holders of Units deemed to be the Holders, for purposes of this Section 13, of the number of Registrable Shares into which such Units are or would be convertible as of the date on which such consent is requested). Notwithstanding the foregoing, a waiver or consent to depart from the provisions hereof with respect to a matter that relates exclusively to the rights of Holders whose securities are being sold pursuant to a Registration Statement and that does not directly or indirectly affect the rights of other Holders may be given by Holders of at least a majority of the Registrable Securities being sold by such Holders pursuant to such Registration Statement; provided that the provisions of this sentence may not be amended, modified or supplemented except in accordance with the provisions of the immediately preceding sentence. Notwithstanding the foregoing two sentences, this Agreement may be amended by written agreement signed by the Trust and BPLP, without the consent of the Holders of Registrable Shares, to cure any ambiguity or to correct or supplement any provision contained herein that may be defective or inconsistent with any other provision contained herein, or to make such other provisions in regard to matters or questions arising under this Agreement that shall not adversely affect the interests of the Holders of Registrable Shares. Each Holder of Registrable Shares outstanding at the time of any such amendment, modification, supplement, waiver or consent or thereafter shall be bound by any such amendment, modification, supplement, waiver or consent effected pursuant to this Section 13, whether or not any notice, writing or marking indicating such amendment, modification, supplement, waiver or consent appears on the Registrable Shares or is delivered to such Holder.

     14. Notices All notices and other communications provided for or permitted hereunder shall be made in writing by hand delivery, by telecopier, by courier guaranteeing overnight delivery or by first-class mail, return receipt requested, and shall be deemed given (i) when made, if made by hand delivery, (ii) upon confirmation, if made by telecopier, (iii) one (1) Business Day after being deposited with such courier, if made by a recognized overnight courier or (iv) on the date indicated on the notice of receipt, if made by first-class mail, to the parties as follows:

     If to the Trust:

Archstone-Smith Trust

9200 E. Panorama, Suite 400

Englewood, Colorado 80112

Attn: General Counsel

Telecopy: (303) 708-6954

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     with a copy to:

Mayer, Brown, Rowe and Maw LLP

71 South Wacker Drive

Chicago, Illinois 60606

Attn: Edward J. Schneidman

Telecopy: (312) 706-8200

     If to a Holder:

At the most current address given by such Holder to the Trust in a Notice and Questionnaire or any amendment thereto.

     15. Successors and Assigns. This Agreement shall be binding upon the parties hereto and their respective successors and assigns and shall inure to the benefit of the parties hereto and their respective successors and assigns. If any successor, assignee or transferee of any Holder shall acquire Units or Registrable Shares, in any manner, whether by operation of law or otherwise, (i) such successor, assignee or transferee shall be entitled to all of the benefits of a “Holder” under this Agreement and (ii) such Registrable Shares shall be held subject to all of the terms of this Agreement, and by taking and holding such Registrable Shares such Person shall be conclusively deemed to have agreed to be bound by all of the terms and provisions hereof.

     16. Counterparts. This Agreement may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement.

     17. Governing Law This Agreement shall be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed wholly within said state.

     18. Third Party Beneficiary and Remedies. Each of the Holders shall be a third party beneficiary of this Agreement, with full rights of enforcement as if a party hereto. The remedies provided for herein are not exclusive and shall not limit any rights or remedies which may otherwise be available to any Holder at law or in equity. The Trustee shall be entitled, on behalf of Holders, to seek any available remedy for the enforcement of this Agreement

     19. Severability. In the event that any one or more of the provisions contained herein, or the application thereof in any circumstances, is held invalid, illegal or unenforceable in any respect for any reason, the validity, legality and enforceability of any such provision in every other respect and of the remaining provisions contained herein shall not be in any way impaired thereby, it being intended that all of the rights and privileges of the parties hereto shall be enforceable to the fullest extent permitted by law.

     20. Entire Agreement. This Agreement is intended by the parties as a final expression of their agreement and intended to be the complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein. There are

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no restrictions, promises, warranties or undertakings, other than those set forth or referred to herein, with respect to such subject matter. This Agreement supersedes all prior agreements and understandings between the parties with respect to such subject matter.

[The Remainder of This Page Has Been Intentionally Left Blank.]

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     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the date first written above.

ARCHSTONE-SMITH TRUST, a Maryland real estate investment trust
By:
Name:	Rick D. Jacobsen
Title:	Senior Vice President and Treasurer
ARCHSTONE-SMITH OPERATING TRUST, a Maryland real estate investment trust
By:
Name:	Rick D. Jacobsen
Title:	Senior Vice President and Treasurer

S-1

EX-10.2

Exhibit 10.2

ARCHSTONE-SMITH OPERATING TRUST
9200 E. Panorama Circle, Suite 400
Englewood, Colorado 80112

July 14, 2006

Archstone-Smith Trust
9200 E. Panorama Circle, Suite 400
Englewood, Colorado 80112

On this date we have executed and delivered the Third Supplemental Indenture dated as of July 14, 2006 to that certain the Indenture dated as of February 1, 1994, between Archstone-Smith Operating Trust, a Maryland real estate investment trust (the “Company”), and Morgan Guaranty Trust Company of New York, as trustee (“Morgan”), as supplemented by the First Supplemental Indenture dated as of February 2, 1994, between the Company, Morgan and U.S. Bank National Association (as successor in interest to State Street Bank and Trust Company), as successor trustee (the “Trustee”), and as further supplemented by the Second Supplemental Indenture dated as of August 2, 2004, between the Company and the Trustee, pursuant to which the Company issued $575,000,000 principal amount of its 4.0% Exchangeable Senior Notes due 2036 (the “Notes”). Article 8 of the Third Supplemental Indenture provides that under the circumstances and subject to the terms and conditions set forth therein, the Company has the right to deliver to holders of the Notes the common shares of beneficial interest of, par value $.01 per share (“Common Shares”), of Archstone-Smith Trust (the “Trust”) in satisfaction of all or a portion of the Company’s obligations under the Notes, at the election of the Company. If the Company elects to deliver Common Shares on account of Notes, such shares will first have to be issued by the Trust and then delivered at the direction of the Company to holders of the Notes. This letter agreement is intended to evidence the Trust’s contractual commitment to so issue Common Shares.

By countersigning this letter, the Trust hereby agrees that, if and when the Company gives notice to the Trust that it has elected under the Indenture to deliver Common Shares in satisfaction of any of its obligations under the Notes, which notice shall include references to the applicable provisions of the Indenture and calculations of the number of Common Shares to be delivered, the Trust shall issue within three (3) business days the required number of Common Shares and direct the transfer agent for the Common Shares to deliver such shares as instructed by the Company to holders of the Notes. The Trust will (i) issue Common Shares as described above under a then available registration statement under the Securities Act of 1933, as amended (the “Securities Act”) without transfer restrictions or (ii) as provided in Section 8.13 of the Third Supplemental Indenture, issue Common Shares that when so issued are “restricted securities” under the Securities Act (“Restricted Shares”). As of the date of this letter the Trust and the Company have entered into a Registration Rights Agreement granting the Company for the benefit of holders of Notes certain registration rights under the Securities Act with respect to such Restricted Shares.

This letter shall be governed by and construed in accordance with the laws of the State of New York applicable to contracts made and to be performed wholly within said state, without giving affect to the conflict of laws principles thereof.

[Reminder of page intentionally left blank]

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Please indicate your acceptance and agreement by signing below.

Sincerely Yours,
ARCHSTONE-SMITH OPERATING TRUST
By:
Name:	Rick D. Jacobsen
Title:	Senior Vice President and Treasurer

ACCEPTED AND AGREED BY:

ARCHSTONE-SMITH TRUST

By:
Name:	Rick D. Jacobsen
Title:	Senior Vice President and Treasurer

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