exv1w1

OTTER TAIL CORPORATION

(a Minnesota corporation)

4,500,000 Common Shares

(Par Value $5.00 Per Share)

PURCHASE AGREEMENT

September 18, 2008

MERRILL LYNCH & CO.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
Robert W. Baird & Co. Incorporated
J.P. Morgan Securities Inc.
Banc of America Securities LLC
Wells Fargo Securities, LLC
KeyBanc Capital Markets Inc.

as Representatives of the several Underwriters

c/o Merrill Lynch & Co.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
4 World Financial Center
New York, New York 10080

Ladies and Gentlemen:

Otter Tail Corporation, a Minnesota corporation (the “Company”) confirms its agreement with Merrill Lynch & Co., Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters,” which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom Merrill Lynch and Robert W. Baird & Co. Incorporated, J.P. Morgan Securities Inc., Banc of America Securities LLC, Wells Fargo Securities, LLC and KeyBanc Capital Markets Inc. are acting as representatives (in such capacity, the “Representatives”), with respect to (i) the sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective numbers of common shares, par value $5.00 per share, of the Company (“Common Stock”) set forth in Schedule A hereto and (ii) the grant by the Company to the Underwriters, acting severally and not jointly, of the option described in Section 2(b) hereof to purchase all or any part of 675,000 additional shares of Common Stock to cover overallotments, if any. The aforesaid shares of Common Stock set forth in Schedule A (the “Initial Securities”) to be purchased by the Underwriters and all or any part of

the 675,000 shares of Common Stock subject to the option described in Section 2(b) hereof (the “Option Securities”) are hereinafter called, collectively, the “Securities.”

The Company understands that the Underwriters propose to make a public offering of the Securities as soon as the Representatives deem advisable after this Agreement has been executed and delivered.

The Company has filed with the Securities and Exchange Commission (the “Commission”) a shelf registration statement on Form S-3 (No. 333-116206), including the related preliminary prospectus or prospectuses, which registration statement subsequently became effective under the Securities Act of 1933, as amended (the “1933 Act”). Such registration statement covers the registration of the Securities under the 1933 Act. Promptly after execution and delivery of this Agreement, the Company will prepare and file a prospectus in accordance with the provisions of Rule 430B (“Rule 430B”) of the rules and regulations of the Commission (the “1933 Act Regulations”) and paragraph (b) of Rule 424 (“Rule 424(b)”) of the 1933 Act Regulations. Any information included in such prospectus that was omitted from such registration statement at the time it became effective but that is deemed to be part of and included in such registration statement pursuant to Rule 430B is referred to as “Rule 430B Information.” Each prospectus used in connection with the offering of the Securities that omitted Rule 430B Information is herein called a “preliminary prospectus.” Such registration statement, at any given time, including the amendments thereto to such time, the exhibits and any schedules thereto at such time, the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act at such time and the documents otherwise deemed to be a part thereof or included therein by 1933 Act Regulations, is herein called the “Registration Statement.” The Registration Statement at the time it originally became effective is herein called the “Original Registration Statement.” The final prospectus in the form first furnished to the Underwriters for use in connection with the offering of the Securities, including the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act at the time of the execution of this Agreement and any preliminary prospectuses that form a part thereof, is herein called the “Prospectus.” For purposes of this Agreement, all references to the Registration Statement, any preliminary prospectus, the Prospectus or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system (“EDGAR”).

All references in this Agreement to financial statements and schedules and other information which is “contained,” “included” or “stated” in the Registration Statement, any preliminary prospectus or the Prospectus (or other references of like import) shall be deemed to mean and include all such financial statements and schedules and other information that is incorporated by reference in or otherwise deemed by 1933 Act Regulations to be a part of or included in the Registration Statement, any preliminary prospectus or the Prospectus, as the case may be; and all references in this Agreement to amendments or supplements to the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to mean and include the filing of any document under the Securities Exchange Act of 1934 (the “1934 Act”) which is incorporated by reference in or otherwise deemed by 1933 Act Regulations to be a part of or included in the Registration Statement, such preliminary prospectus or the Prospectus, as the case may be.

SECTION 1. Representations and Warranties.

(a) Representations and Warranties by the Company. The Company represents and warrants to each Underwriter as of the date hereof, the Applicable Time referred to in Section 1(a)(i) hereof and as of the Closing Time referred to in Section 2(c) hereof, and as of each Date of Delivery (if any) referred to in Section 2(b) hereof, and agrees with each Underwriter, as follows:

(i) Registration Statement, Prospectus and Disclosure at Time of Sale. The Original Registration Statement became effective on August 30, 2004. No stop order suspending the effectiveness of the Registration Statement has been issued under the 1933 Act and no proceedings for that purpose have been instituted or, to the knowledge of the Company, are pending or contemplated by the Commission, and any request on the part of the Commission for additional information has been complied with.

Any offer that is a written communication relating to the Securities made by the Company or any person acting on its behalf (within the meaning, for this paragraph only, of Rule 163(c) of the 1933 Act Regulations) has been filed with the Commission in accordance with the exemption provided by Rule 163 of the 1933 Act Regulations (“Rule 163”) and otherwise complied with the requirements of Rule 163, including without limitation the legending requirement, to qualify such offer for the exemption from Section 5(c) of the 1933 Act provided by Rule 163. At the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) of the 1933 Act Regulations) made any offer relating to the Securities in reliance on the exemption of Rule 163 of the 1933 Act Regulations, the Company was a “well-known seasoned issuer” as defined in Rule 405 of the 1933 Act Regulations (“Rule 405”), including not having been and not being an “ineligible issuer” as defined in Rule 405.

At the respective times the Original Registration Statement and each amendment thereto became effective, at each deemed effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations and at the Closing Time (and, if any Option Securities are purchased, at the Date of Delivery), the Registration Statement complied and will comply in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations and did not and will not contain 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 not misleading.

Neither the Prospectus nor any amendments or supplements thereto, at the time the Prospectus or any such amendment or supplement was issued and at the Closing Time (and, if any Option Securities are purchased, at the Date of Delivery), included or will include an untrue statement of a material fact or omitted or will 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.

Each preliminary prospectus (including the prospectus or prospectuses filed as part of the Original Registration Statement or any amendment thereto) complied when so filed in all material respects with the 1933 Act Regulations and each preliminary

prospectus and the Prospectus delivered to the Underwriters for use in connection with this offering was identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

As of the Applicable Time (as defined below), neither (x) the Issuer General Use Free Writing Prospectus(es) (as defined below) issued at or prior to the Applicable Time, the Statutory Prospectus (as defined below) and the information included on Schedule C hereto, all considered together (collectively, the “General Disclosure Package”), nor (y) any individual Issuer Limited Use Free Writing Prospectus, when considered together with the General Disclosure Package, included 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 the circumstances under which they were made, not misleading.

As used in this subsection and elsewhere in this Agreement:

“Applicable Time” means 7:30 a.m. (Eastern Time) on September 19, 2008 or such other time as agreed by the Company and Merrill Lynch.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the 1933 Act Regulations (“Rule 433”), relating to the Securities that (i) is required to be filed with the Commission by the Company, (ii) is a “road show that is a written communication” within the meaning of Rule 433(d)(8)(i), whether or not required to be filed with the Commission or (iii) is exempt from filing pursuant to Rule 433(d)(5)(i) because it contains a description of the Securities or of the offering that does not reflect the final terms, in each case in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g).

“Issuer General Use Free Writing Prospectus” means any Issuer Free Writing Prospectus that is intended for general distribution to prospective investors (other than a Bona Fide Electronic Road Show (as defined below)), as evidenced by its being specified in Schedule E hereto.

“Issuer Limited Use Free Writing Prospectus” means any Issuer Free Writing Prospectus that is not an Issuer General Use Free Writing Prospectus.

“Statutory Prospectus” as of any time means the prospectus relating to the Securities that is included in the Registration Statement immediately prior to that time, including any document incorporated by reference therein and any preliminary or other prospectus deemed to be a part thereof.

The Company has made available a “bona fide electronic road show,” as defined in Rule 433, in compliance with Rule 433(d)(8)(i) (the “Bona Fide Electronic Road Show”) such that no filing of any “road show” (as defined in Rule 433(h)) is required in connection with the offering of the Securities.

Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Securities or until any

earlier date that the issuer notified or notifies Merrill Lynch as described in Section 3(e), did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement or the Prospectus, including any document incorporated by reference therein and any preliminary or other prospectus deemed to be a part thereof that has not been superseded or modified.

The representations and warranties in this subsection shall not apply to statements in or omissions from the Registration Statement, the Prospectus or any Issuer Free Writing Prospectus made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through Merrill Lynch expressly for use therein.

(ii) Incorporated Documents. The documents incorporated or deemed to be incorporated by reference in the Registration Statement and the Prospectus at the time they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the 1934 Act and the rules and regulations of the Commission thereunder (the “1934 Act Regulations”), and, when read together with the other information in the Prospectus, (a) at the time the Original Registration Statement became effective, (b) at the earlier of the time the Prospectus was first used and the date and time of the first contract of sale of Securities in this offering and (c) at the Closing Time (and, if any Option Securities are purchased, at the Date of Delivery), did not and will not contain 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 not misleading.

(iii) Independent Accountants. The accountants who certified the financial statements and supporting schedules included in the Registration Statement are independent public accountants as required by the 1933 Act and the 1933 Act Regulations.

(iv) Financial Statements. The financial statements included in the Registration Statement, the General Disclosure Package and the Prospectus, together with the related schedules and notes, present fairly in all material respects the financial position of the Company and its consolidated subsidiaries at the dates indicated and the statement of operations, stockholders’ equity and cash flows of the Company and its consolidated subsidiaries for the periods specified; said financial statements have been prepared in conformity with the 1933 Act, the 1933 Act Regulations and generally accepted accounting principles (“GAAP”) applied on a consistent basis throughout the periods involved. The supporting schedules, if any, present fairly in accordance with the 1933 Act, the 1933 Act Regulations and GAAP the information required to be stated therein. The selected financial data and the summary financial information included in the General Disclosure Package and the Prospectus present fairly the information shown therein and have been compiled on a basis consistent in all material respects with that of the audited financial statements included in the Registration Statement and the books and records of the Company. There are no financial statements (historical or pro forma) that are required to be included in the Registration Statement, the General Disclosure Package and the Prospectus that are not included as required, and the Company and its

consolidated subsidiaries do not have any material liabilities or obligations, direct or contingent (including any off-balance sheet obligations), not disclosed in the Registration Statement, the General Disclosure Package and the Prospectus.

(v) No Material Adverse Change in Business. Since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, except as otherwise stated therein, (A) there has been no material adverse change or any development involving a prospective material adverse change, in the business, properties, management, financial condition or results of operations of the Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business (a “Material Adverse Effect”), (B) there have been no transactions entered into by the Company or any of its subsidiaries, other than those in the ordinary course of business, which are material with respect to the Company and its subsidiaries considered as one enterprise, (C) there have been no obligations, direct or contingent (including any off-balance sheet obligations), incurred by the Company or its consolidated subsidiaries, which are material with respect to the Company and its subsidiaries considered as one enterprise, (D) there have been no changes in the capital stock (except for issuances of Common Stock under the Company’s 1999 Stock Incentive Plan, as amended, 1999 Employee Stock Purchase Plan, as amended, Automatic Dividend Reinvestment and Share Purchase Plan, Employee Stock Ownership Plan and Deferred Compensation Plan for Directors) or outstanding indebtedness (except for increases or decreases in short-term debt not in excess of an aggregate of $70.0 million) of the Company and its subsidiaries, or (E) except for regular quarterly cash dividends in amounts per share that are consistent with past practice, there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock.

(vi) Good Standing of the Company. The Company has been duly organized and is validly existing as a corporation in good standing under the laws of the State of Minnesota and has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the General Disclosure Package and the Prospectus and to enter into and perform its obligations under this Agreement; and the Company is duly qualified as a foreign corporation to transact business and is in good standing in each other jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect.

(vii) Good Standing of Subsidiaries. The only direct and indirect subsidiaries of the Company are the subsidiaries listed on Schedule G hereto (each a “Subsidiary” and, collectively, the “Subsidiaries”). Each Subsidiary identified with a “*” on Schedule G is referred to herein as a “Significant Subsidiary,” and there is no Subsidiary that would constitute a “significant subsidiary” as defined in Rule 1-02 of Regulation S-X, but is not identified as a Significant Subsidiary on Schedule G hereto. Each Significant Subsidiary of the Company has been duly organized and is validly existing as a corporation or other legal entity in good standing under the laws of the jurisdiction of its incorporation or organization, has corporate or other power and authority to own, lease

and operate its properties and to conduct its business as described in the General Disclosure Package and the Prospectus and is duly qualified as a foreign corporation or other legal entity to transact business and is in good standing, in each case in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect; except as otherwise disclosed in the Registration Statement, all of the issued and outstanding capital stock or other equity interests of each such Significant Subsidiary have been duly authorized and validly issued, are fully paid and non-assessable and are owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity; none of the outstanding shares of capital stock or other equity interests of any Significant Subsidiary were issued in violation of the preemptive right, resale right, right of first refusal or other similar rights of any security holder of such Subsidiary. Except as set forth on Schedule G hereto, the Company owns 100% of the outstanding capital stock or other equity interests of each Subsidiary.

(viii) Capitalization. The authorized, issued and outstanding capital stock of the Company is as set forth in the General Disclosure Package and the Prospectus (except for subsequent issuances, if any, pursuant to this Agreement, pursuant to reservations, agreements or employee benefit plans referred to in the General Disclosure Package and the Prospectus or pursuant to the exercise of options referred to in the General Disclosure Package and the Prospectus). The shares of issued and outstanding capital stock, including the Common Stock, of the Company, have been duly authorized and validly issued, are fully paid and non-assessable and were issued in compliance with all federal and state securities laws; none of the outstanding shares of capital stock, including the Common Stock, of the Company were issued in violation of any preemptive right, resale right, right of first refusal or other similar rights of any security holder of the Company. Other than the capital stock or other equity interests of the Subsidiaries and the investments set forth on Schedule G hereto, the Company does not own, directly or indirectly, any shares of stock or any other equity or long-term debt securities of any corporation or have any equity interest in any firm, partnership, joint venture, association or other entity. Complete and correct copies of the articles of incorporation and by-laws of the Company and all amendments thereto have been delivered to the Underwriters.

(ix) Authorization of Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(x) Authorization and Description of Securities. The Securities to be purchased by the Underwriters from the Company have been duly authorized for issuance and sale to the Underwriters pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued and fully paid and non-assessable; the capital stock of the Company, including the Common Stock, conforms to all statements relating thereto contained in the General Disclosure Package and the Prospectus and such description conforms to the rights set forth in the instruments defining the same; no holder of the Securities will be subject to personal liability by reason of being such a holder; and the issuance of the Securities is not subject to any statutory and contractual preemptive

rights, resale rights, rights of first refusal and similar rights of any security holder of the Company.

(xi) Absence of Defaults and Conflicts. Neither the Company nor any of its Subsidiaries are in violation of its charter, by-laws or other governing documents, or in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or other agreement or instrument to which the Company or any of its Subsidiaries is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any Subsidiary is subject (collectively, “Agreements and Instruments”) except for such defaults that would not result in a Material Adverse Effect; and the execution, delivery and performance of this Agreement and the consummation of the transactions contemplated herein and in the Registration Statement (including the issuance and sale of the Securities and the use of the proceeds from the sale of the Securities as described in the General Disclosure Package and the Prospectus under the caption “Use of Proceeds”) and compliance by the Company with its obligations hereunder have been duly authorized by all necessary corporate action and do not and will not, whether with or without the giving of notice or passage of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any Subsidiary pursuant to, the Agreements and Instruments (except for such conflicts, breaches, defaults or Repayment Events or liens, charges or encumbrances that would not result in a Material Adverse Effect), nor will such action result in any violation of the provisions of the charter, by-laws or similar governing documents of the Company or any Subsidiary or any applicable law, statute, rule, regulation, judgment, order, writ or decree of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company or any Subsidiary or any of their assets, properties or operations. As used herein, a “Repayment Event” means any event or condition which gives the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company or any Subsidiary.

(xii) Labor Dispute. Except for matters which would not, individually or in the aggregate, have a Material Adverse Effect, (i) neither the Company nor any of its Subsidiaries is engaged in any unfair labor practice; (ii) there is (a) no unfair labor practice complaint pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries before the National Labor Relations Board, and no grievance or arbitration proceeding arising out of or under collective bargaining agreements is pending or threatened, (b) no strike, labor dispute, slowdown or stoppage pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries and (c) no union representation dispute currently existing concerning the employees of the Company or any of its Subsidiaries, and (iii) to the Company’s knowledge (a) no union organizing activities are currently taking place concerning the employees of the Company or any of its Subsidiaries and (b) there has been no violation of any federal, state, local or foreign law relating to discrimination in the hiring, promotion or pay of employees, any applicable wage or hour laws or any provision of the

Employee Retirement Income Security Act of 1974 or the rules and regulations promulgated thereunder concerning the employees of the Company or any of its Subsidiaries.

(xiii) Absence of Proceedings. There is no action, suit, proceeding, inquiry or investigation before or brought by any court or governmental agency or body, domestic or foreign, now pending, or, to the knowledge of the Company, threatened, against or affecting the Company or any Subsidiary, which is required to be disclosed in the Registration Statement (other than as disclosed therein), or which would reasonably be expected to result in a Material Adverse Effect, or which would reasonably be expected to materially and adversely affect properties or assets thereof or the consummation of the transactions contemplated in this Agreement or the performance by the Company of its obligations hereunder; the aggregate of all pending legal or governmental proceedings to which the Company or any Subsidiary is a party or of which any of their respective property or assets is the subject which are not described in the Registration Statement, including ordinary routine litigation incidental to the business, could not result in a Material Adverse Effect.

(xiv) Accuracy of Exhibits. There are no proceedings, affiliate transactions, off-balance sheet transactions, contracts, licenses, agreements, leases or documents that are required to be described in the Registration Statement, the General Disclosure Package, the Prospectus or the documents incorporated by reference therein or to be filed as exhibits thereto which have not been so described and filed as required. The Company has not sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements described in the Registration Statement, the General Disclosure Package, the Prospectus or the documents incorporated by reference therein or filed as exhibits thereto, and no such termination or non-renewal has been threatened by the Company or, to the Company’s knowledge, any other party to any such contract or agreement.

(xv) Possession of Intellectual Property. The Company and its Subsidiaries own, or have obtained valid and enforceable licenses for, or other rights to use, the inventions, patent applications, patents, trademarks (both registered and unregistered), tradenames, copyrights, trade secrets and other proprietary information described in the Registration Statement, the General Disclosure Package and the Prospectus as being owned or licensed by them or which are necessary for the conduct of their respective businesses (collectively, “Intellectual Property”), except where the failure to own, license or have such rights would not, individually or in the aggregate, have a Material Adverse Effect. Except for matters which would not, individually or in the aggregate, have a Material Adverse Effect, (i) there are no third parties who have or, to the Company’s knowledge after due inquiry, will be able to establish rights to any Intellectual Property, except for the ownership rights of the owners of the Intellectual Property which is licensed to the Company; (ii) there is no infringement by third parties of any Intellectual Property; (iii) there is no pending or threatened action, suit, proceeding or claim by others challenging the Company’s rights in or to any Intellectual Property, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (iv) there is no pending or threatened action, suit, proceeding or claim by others challenging the

validity or scope of any Intellectual Property, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (v) there is no pending or threatened action, suit, proceeding or claim by others that the Company infringes or otherwise violates any patent, trademark, copyright, trade secret or other proprietary rights of others, and the Company is unaware of any facts which would form a reasonable basis for any such claim; (vi) there is no patent or patent application that contains claims that interfere with the issued or pending claims of any of the Intellectual Property; and (vii) there is no prior art that may render any patent application owned by the Company of the Intellectual Property unpatentable that has not been disclosed to the U.S. Patent and Trademark Office.

(xvi) Absence of Manipulation. Neither the Company nor, to the Company’s knowledge, any director, officer, employee or affiliate of the Company has taken, nor will the Company or any director, officer, employee or affiliate of the Company take, directly or indirectly, any action which is designed to or which has constituted or which would reasonably be expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Securities.

(xvii) Absence of Further Requirements. No filing with, or authorization, approval, consent, license, order, registration, qualification or decree of, any court or governmental authority or agency is necessary or required for the performance by the Company of its obligations hereunder, in connection with the offering, issuance or sale of the Securities hereunder or the consummation of the transactions contemplated by this Agreement, except such as have been already obtained or as may be required under the 1933 Act or the 1933 Act Regulations or state or foreign securities laws.

(xviii) Possession of Licenses and Permits. The Company and its Subsidiaries possess such permits, licenses, approvals, consents and other authorizations (collectively, “Governmental Licenses”) issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the business now operated by them, except where the failure so to possess would not, singly or in the aggregate, result in a Material Adverse Effect; the Company and its Subsidiaries are in compliance with the terms and conditions of all such Governmental Licenses, except where the failure so to comply would not, singly or in the aggregate, result in a Material Adverse Effect; all of the Governmental Licenses are valid and in full force and effect, except when the invalidity of such Governmental Licenses or the failure of such Governmental Licenses to be in full force and effect would not, singly or in the aggregate, result in a Material Adverse Effect; and neither the Company nor any of its Subsidiaries has received any notice of proceedings relating to the revocation or modification of any such Governmental Licenses which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Effect.

(xix) Title to Property. The Company and its Subsidiaries have good and marketable title to all real property owned by the Company and its Subsidiaries and good title to all other properties owned by them, in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind except such as (a) are described in the General Disclosure Package and the Prospectus or (b) do

not, singly or in the aggregate, 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 or any of its Subsidiaries; and all of the leases and subleases material to the business of the Company and its Subsidiaries, considered as one enterprise, and under which the Company or any of its Subsidiaries holds properties described in the General Disclosure Package and the Prospectus, are in full force and effect, and neither the Company nor any Subsidiary has any notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company or any Subsidiary under any of the leases or subleases mentioned above, or affecting or questioning the rights of the Company or such Subsidiary to the continued possession of the leased or subleased premises under any such lease or sublease, except for such claims as would not, individually or in the aggregate, have a Material Adverse Effect.

(xx) Investment Company Act. The Company is not required, and upon the issuance and sale of the Securities as herein contemplated and the application of the net proceeds therefrom as described in the General Disclosure Package and the Prospectus will not be required, to register as an “investment company” under the Investment Company Act of 1940, as amended (the “1940 Act”).

(xxi) Environmental Laws. Except as described in the Registration Statement, General Disclosure Package or the Prospectus, and except as would not, singly or in the aggregate, result in a Material Adverse Effect, (A) to the knowledge of the Company, neither the Company nor any of its Subsidiaries is in violation of any federal, state, local or foreign statute, law, rule, regulation, ordinance, code, policy or rule of common law or any judicial or administrative interpretation thereof, including any judicial or administrative order, consent, decree or judgment, relating to pollution or protection of human health, the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, laws and regulations relating to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products, asbestos-containing materials or mold (collectively, “Hazardous Materials”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “Environmental Laws”), (B) the Company and its Subsidiaries have all permits, authorizations and approvals required under any applicable Environmental Laws and are each in compliance with their requirements, (C) there are no pending or threatened administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings relating to any Environmental Law against the Company or any of its Subsidiaries, (D) to the knowledge of the Company, there are no events or circumstances that would reasonably be expected to form the basis of an order for clean-up or remediation, or an action, suit or proceeding by any private party or governmental body or agency, against or affecting the Company or any of its Subsidiaries relating to Hazardous Materials or any Environmental Laws, and (E) neither the Company nor any of its Subsidiaries has entered into any agreement relating any alleged violation of any Environmental Law or any actual or alleged release or threatened release or clean-up at any location of any Hazardous Materials.

(xxii) Accounting Controls and Disclosure Controls. The Company and each of its Subsidiaries maintain a system of internal accounting controls sufficient to provide reasonable assurances that (1) transactions are executed in accordance with management’s general or specific authorization; (2) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets; (3) access to assets is permitted only in accordance with management’s general or specific authorization; and (4) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as described in the General Disclosure Package and the Prospectus, since the end of the Company’s most recent audited fiscal year, there has been (I) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (II) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting. The Company’s auditors and the Audit Committee of the Board of Directors have been advised of: (A) any significant deficiencies in the design or operation of internal controls which could adversely affect the Company’s ability to record, process, summarize, and report financial data; and (B) any fraud, whether or not material, that involves management or other employees who have a role in the Company’s internal controls.

The Company and its consolidated Subsidiaries employ disclosure controls and procedures that are designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the 1934 Act is recorded, processed, summarized and reported, within the time periods specified in the Commission’s rules and forms, and is accumulated and communicated to the Company’s management, including its principal executive officer or officers and principal financial officer or officers, as appropriate, to allow timely decisions regarding disclosure.

(xxiii) Compliance with the Sarbanes-Oxley Act. There is and has been no failure on the part of the Company or any of the Company’s directors or officers, in their capacities as such, to comply in all material respects with any provision of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith, including Section 402 related to loans and Sections 302 and 906 related to certifications.

(xxiv) Pending Proceedings and Examinations. The Registration Statement is not the subject of a pending proceeding or examination under Section 8(d) or 8(e) of the 1933 Act, and the Company is not the subject of a pending proceeding under Section 8A of the 1933 Act in connection with the offering of the Securities.

(xxvi) Payment of Taxes. All material United States federal income tax returns of the Company and its Subsidiaries required by law to be filed have been filed and all material taxes shown by such returns or otherwise assessed, which are due and payable, have been paid, except assessments against which appeals have been or will be promptly taken and as to which adequate reserves have been provided. The United States federal income tax returns of the Company through the fiscal year ended December 31, 2002 have been settled and no assessment in connection therewith has been made against the

Company. The Company and its Subsidiaries have filed all other material tax returns that are required to have been filed by them pursuant to applicable foreign, state, local or other law except insofar as the failure to file such returns would not result in a Material Adverse Effect, and has paid all material taxes due pursuant to such returns or pursuant to any assessment received by the Company and its Subsidiaries, except for such taxes, if any, as are being contested in good faith and as to which adequate reserves have been provided. The charges, accruals and reserves on the books of the Company in respect of any income and corporation tax liability for any years not finally determined are adequate to meet any assessments or re-assessments for additional income tax for any years not finally determined, except to the extent of any inadequacy that would not result in a Material Adverse Effect.

(xxvii) Insurance. The Company and its Subsidiaries carry or are entitled to the benefits of insurance, with financially sound and reputable insurers, in such amounts and covering such risks as is generally maintained by companies of established repute engaged in the same or similar business, and all such insurance is in full force and effect. The Company has no reason to believe that it or any Subsidiary will not be able (A) to renew its existing insurance coverage as and when such policies expire or (B) to obtain comparable coverage from similar institutions as may be necessary or appropriate to conduct its business as now conducted and at a cost that would not result in a Material Adverse Effect. Neither of the Company nor any Subsidiary has been denied any insurance coverage which it has sought or for which it has applied.

(xxviii) Statistical and Market-Related Data. Any statistical and market-related data included in the Registration Statement, the General Disclosure Package and the Prospectus are based on or derived from sources that the Company believes to be reliable and accurate.

(xxix) No Commitments. Except as set forth in the Registration Statement, the General Disclosure Package and the Prospectus, (A) no person has the right, contractual or otherwise, to cause the Company to issue or sell to it any shares of Common Stock or shares of any other capital stock or other equity interests of the Company, except under the Company’s 1999 Stock Incentive Plan, as amended, 1999 Employee Stock Purchase Plan, as amended, Automatic Dividend Reinvestment and Share Purchase Plan, Employee Stock Ownership Plan and Deferred Compensation Plan for Directors (each of which is disclosed in the Registration Statement, the General Disclosure Package and the Prospectus or documents incorporated by referenced therein), (B) no person has any preemptive rights, resale rights, rights of first refusal or other rights to purchase any shares of Common Stock or shares of any other capital stock or other equity interests of the Company, and (C) no person has the right to act as an underwriter or as a financial advisor to the Company in connection with the offer and sale of the Securities, in the case of each of the foregoing clauses (A), (B) and (C), whether as a result of the filing of the Registration Statement, the General Disclosure Package or the Prospectus or the sale of the Securities as contemplated thereby or otherwise; no person has the right, contractual or otherwise, to cause the Company to register under the 1933 Act or the 1933 Act Regulations any shares of Common Stock or shares of any other capital stock or other equity interests of the Company, or to include any such shares or interests in the

Registration Statement, the General Disclosure Package or the Prospectus or the offering contemplated thereby, whether as a result of the filing of the Registration Statement, the General Disclosure Package or the Prospectus or the sale of the Securities as contemplated thereby or otherwise.

(xxv) Business Disruption. Neither the Company nor any of its Subsidiaries has sustained since the date of the last audited financial statements included in the Registration Statement, the General Disclosure Package and the Prospectus any loss or interference with its respective business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any or court or governmental action, order or decree, except as described in the Registration Statement, the General Disclosure Package and the Prospectus or that would not, individually or in the aggregate, have a Material Adverse Effect.

(xxvi) Foreign Corrupt Practices Act. Neither the Company nor, to the knowledge of the Company, any director, officer, agent, employee, affiliate or other person acting on behalf of the Company or any of its Subsidiaries is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of the Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “FCPA”), including without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly in the furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA and the Company and to the knowledge of the Company, its affiliates have conducted their businesses in compliance with the FCPA and have instituted and maintain policies and procedures designed to ensure and which are reasonable expected to continue to ensure, continued compliance therewith.

(xxvii) Money Laundering Laws. The operations of the Company are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all jurisdictions, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company, threatened.

(xxviii) OFAC. Neither the Company nor, to the knowledge of the Company, any director, officer, agent, employee, affiliate or person acting on behalf of the Company is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasure Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any Subsidiary, joint venture partner or other person or

entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC.

(xxix) NASD Filing Exemption. At the time of effectiveness of the Registration Statement, the Company was eligible to use Form S-3 pursuant to the standards for that Form prior to October 21, 1992.

(b) Officer’s Certificates. Any certificate signed by any officer of the Company or any of its Subsidiaries delivered to the Representatives or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to each Underwriter as to the matters covered thereby.

SECTION 2. Sale and Delivery to Underwriters; Closing.

(a) Initial Securities. On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company agrees to sell to each Underwriter, severally and not jointly, and each Underwriter, severally and not jointly, agrees to purchase from the Company, at the price per share set forth in Schedule D, that proportion of the number of Initial Securities set forth in Schedule B opposite the name of the Company, which the number of Initial Securities set forth in Schedule A opposite the name of such Underwriter, plus any additional number of Initial Securities which such Underwriter may become obligated to purchase pursuant to the provisions of Section 10 hereof, bears to the total number of Initial Securities, subject, in each case, to such adjustments among the Underwriters as the Representatives in their sole discretion shall make to eliminate any sales or purchases of fractional securities.

(b) Option Securities. In addition, on the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company hereby grants an option to the Underwriters, severally and not jointly, to purchase up to an additional 675,000 shares of Common Stock, as set forth in Schedule B, at the price per share set forth in Schedule D, less an amount per share equal to any dividends or distributions declared by the Company and payable on the Initial Securities but not payable on the Option Securities. The option hereby granted will expire 30 days after the date hereof and may be exercised in whole or in part from time to time only for the purpose of covering overallotments which may be made in connection with the offering and distribution of the Initial Securities upon notice by Merrill Lynch to the Company setting forth the number of Option Securities as to which the several Underwriters are then exercising the option and the time and date of payment and delivery for such Option Securities. Any such time and date of delivery (a “Date of Delivery”) shall be determined by Merrill Lynch, but shall not be later than seven full business days after the exercise of said option, nor in any event prior to the Closing Time, as hereinafter defined. If the option is exercised as to all or any portion of the Option Securities, each of the Underwriters, acting severally and not jointly, will purchase that proportion of the total number of Option Securities then being purchased which the number of Initial Securities set forth in Schedule A opposite the name of such Underwriter bears to the total number of Initial Securities, subject in each case to such adjustments as Merrill Lynch in its discretion shall make to eliminate any sales or purchases of fractional shares.

(c) Payment. Payment of the purchase price for, and delivery of certificates for, the Initial Securities shall be made at the offices of Winston & Strawn LLP, 35 West Wacker Drive, Chicago, Illinois 60601, or at such other place as shall be agreed upon by the Representatives and the Company, at 9:00 A.M. (Eastern time) on the third (fourth, if the pricing occurs after 4:30 P.M. (Eastern time) on any given day) business day after the date hereof (unless postponed in accordance with the provisions of Section 10), or such other time not later than ten business days after such date as shall be agreed upon by the Representatives and the Company (such time and date of payment and delivery being herein called “Closing Time”).

In addition, in the event that any or all of the Option Securities are purchased by the Underwriters, payment of the purchase price for, and delivery of certificates for, such Option Securities shall be made at the above-mentioned offices, or at such other place as shall be agreed upon by the Representatives and the Company, on each Date of Delivery as specified in the notice from the Representatives to the Company.

Payment shall be made to the Company by wire transfer of immediately available funds to a bank account designated by the Company against delivery to the Representatives for the respective accounts of the Underwriters of certificates for the Securities to be purchased by them. It is understood that each Underwriter has authorized the Representatives, for its account, to accept delivery of, receipt for, and make payment of the purchase price for, the Initial Securities and the Option Securities, if any, which it has agreed to purchase. Merrill Lynch, individually and not as representative of the Underwriters, may (but shall not be obligated to) make payment of the purchase price for the Initial Securities or the Option Securities, if any, to be purchased by any Underwriter whose funds have not been received by the Closing Time or the relevant Date of Delivery, as the case may be, but such payment shall not relieve such Underwriter from its obligations hereunder.

(d) Denominations; Registration. Certificates for the Initial Securities and the Option Securities, if any, shall be in such denominations and registered in such names as the Representatives may request in writing at least one (1) full business day before the Closing Time or the relevant Date of Delivery, as the case may be. The certificates for the Initial Securities and the Option Securities, if any, will be made available for examination and packaging by the Representatives in The City of New York not later than 10:00 A.M. (Eastern time) on the business day prior to the Closing Time or the relevant Date of Delivery, as the case may be.

SECTION 3. Covenants of the Company. The Company covenants with each Underwriter as follows:

(a) Compliance with Securities Regulations and Commission Request. The Company, subject to Section 3(b), will comply with the requirements of Rule 430B and will notify the Representatives immediately, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement or new registration statement relating to the Securities shall become effective, or any supplement to the Prospectus or any amended Prospectus shall have been filed, (ii) of the receipt of any comments from the Commission, (iii) of any request by the Commission for any amendment to the Registration Statement or the filing of a new registration statement or any amendment or supplement to the Prospectus or any document incorporated by reference therein or otherwise deemed to be a part thereof or for

additional information, (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or such new registration statement or of any order preventing or suspending the use of any preliminary prospectus, or of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes or of any examination pursuant to Section 8(e) of the 1933 Act concerning the Registration Statement and (v) if the Company becomes the subject of a proceeding under Section 8A of the 1933 Act in connection with the offering of the Securities. The Company will effect the filings required under Rule 424(b), in the manner and within the time period required by Rule 424(b) (without reliance on Rule 424(b)(8)), and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort to prevent the issuance of any stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

(b) Filing of Amendments and Exchange Act Documents. The Company will give the Representatives notice of its intention to file or prepare any amendment to the Registration Statement or new registration statement relating to the Securities or any amendment, supplement or revision to either any preliminary prospectus (including any prospectus included in the Original Registration Statement or amendment thereto at the time it became effective) or to the Prospectus, whether pursuant to the 1933 Act, the 1934 Act or otherwise, and the Company will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file or use any such document to which the Representatives or counsel for the Underwriters shall object in writing. The Company has given the Representatives notice of any filings made pursuant to the 1934 Act or 1934 Act Regulations within 48 hours prior to the execution of this Agreement; the Company will give the Representatives notice of its intention to make any such filing from the execution of this Agreement to the Closing Time and will furnish the Representatives with copies of any such documents a reasonable amount of time prior to such proposed filing and will not file or use any such document to which the Representatives or counsel for the Underwriters shall object in writing.

(c) Delivery of Registration Statements. The Company has furnished or will deliver to the Underwriters and counsel for the Underwriters, without charge, a conformed copy of the Original Registration Statement and of each amendment thereto (including exhibits filed therewith or incorporated by reference therein and documents incorporated or deemed to be incorporated by reference therein or otherwise deemed to be a part thereof) and conformed copies of all consents and certificates of experts. The copies of the Original Registration Statement and each amendment thereto furnished to the Underwriters and counsel for the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

(d) Delivery of Prospectuses. The Company has delivered to each Underwriter, without charge, as many copies of each preliminary prospectus as such Underwriter reasonably requested, and the Company hereby consents to the use of such copies for purposes permitted by the 1933 Act. The Company will furnish to each Underwriter, without charge, during the period when the Prospectus is required to be delivered under the 1933 Act, such number of copies of the

Prospectus (as amended or supplemented) as such Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

(e) Continued Compliance with Securities Laws. The Company will comply with the 1933 Act and the 1933 Act Regulations and the 1934 Act and the 1934 Act Regulations so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Prospectus. If at any time when a prospectus is required by the 1933 Act to be delivered in connection with sales of the Securities, any event shall occur or condition shall exist as a result of which it is necessary, in the opinion of counsel for the Underwriters or for the Company, to amend the Registration Statement or amend or supplement the Prospectus in order that the Prospectus will not include any untrue statements of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in the light of the circumstances existing at the time it is delivered to a purchaser, or if it shall be necessary, in the opinion of such counsel, at any such time to amend the Registration Statement or to file a new registration statement or amend or supplement the Prospectus in order to comply with the requirements of the 1933 Act or the 1933 Act Regulations, the Company will promptly prepare and file with the Commission, subject to Section 3(b), such amendment, supplement or new registration statement as may be necessary to correct such statement or omission or to comply with such requirements, the Company will use its best efforts to have such amendment or new registration statement declared effective as soon as practicable (if it is not an automatic shelf registration statement with respect to the Securities) and the Company will furnish to the Underwriters such number of copies of such amendment, supplement or new registration statement as the Underwriters may reasonably request. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement (or any other registration statement relating to the Securities) or the Statutory Prospectus or any preliminary prospectus or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at that subsequent time, not misleading, the Company will promptly notify Merrill Lynch and will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission.

(f) Blue Sky Qualifications. The Company will use its best efforts, in cooperation with the Underwriters, to qualify the Securities for offering and sale under the applicable securities laws of such states and other jurisdictions (domestic or foreign) as the Representatives may designate and to maintain such qualifications in effect for a period of not less than one year from the date hereof; provided, however, that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject.

(g) Rule 158. The Company will timely file such reports pursuant to the 1934 Act as are necessary in order to make generally available to its security holders as soon as practicable an

earnings statement for the purposes of, and to provide to the Underwriters the benefits contemplated by, the last paragraph of Section 11(a) of the 1933 Act.

(h) Use of Proceeds. The Company will use the net proceeds received by it from the sale of the Securities in the manner specified in the Prospectus under “Use of Proceeds.”

(i) Listing. The Company will use its best efforts to effect and maintain the quotation of the Securities on the NASDAQ Global Select Market.

(j) Restriction on Sale of Securities. During a period of 90 days from the date of the Prospectus, the Company will not, without the prior written consent of Merrill Lynch, (i) directly or indirectly, 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 or otherwise transfer or dispose of any share of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or file any registration statement under the 1933 Act with respect to any of the foregoing or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Common Stock, whether any such swap or transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (A) the Securities to be sold hereunder, (B) any shares of Common Stock issued by the Company upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof and referred to in the Prospectus, or (C) any shares of Common Stock issued or options to purchase Common Stock granted pursuant to existing employee benefit plans of the Company referred to in the Prospectus, including the Company’s 1999 Stock Incentive Plan, as amended, 1999 Employee Stock Purchase Plan, as amended, Automatic Dividend Reinvestment and Share Purchase Plan, Employee Stock Ownership Plan and Deferred Compensation Plan for Directors (each of which is disclosed in the Registration Statement, the General Disclosure Package and the Prospectus or documents incorporated by referenced therein). Notwithstanding the foregoing, if (1) during the last 17 days of the 90-day restricted period the Company issues an earnings release or material news or a material event relating to the Company occurs or (2) prior to the expiration of the 90-day restricted period, the Company announces that it will release earnings results or becomes aware that material news or a material event will occur during the 16-day period beginning on the last day of the 90-day restricted period, the restrictions imposed in this clause (j) shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

(k) Reporting Requirements. The Company, during the period when the Prospectus is required to be delivered under the 1933 Act, will file all documents required to be filed with the Commission pursuant to the 1934 Act within the time periods required by the 1934 Act and the 1934 Act Regulations.

(l) Issuer Free Writing Prospectuses. The Company represents and agrees that, unless it obtains the prior consent of the Representatives, and each Underwriter represents and agrees that, unless it obtains the prior consent of the Company and the Representatives, it has not made and will not make any offer relating to the Securities that would constitute an “issuer free writing prospectus,” as defined in Rule 433, or that would otherwise constitute a “free writing

prospectus,” as defined in Rule 405, required to be filed with the Commission. Any such free writing prospectus consented to by the Representatives or by the Company and the Representatives, as the case may be, is hereinafter referred to as a “Permitted Free Writing Prospectus.” The Company represents that it has treated or agrees that it will treat each Permitted Free Writing Prospectus as an “issuer free writing prospectus,” as defined in Rule 433, and has complied and will comply with the requirements of Rule 433 applicable to any Permitted Free Writing Prospectus, including timely filing with the Commission where required, legending and record keeping.

SECTION 4. Payment of Expenses.

(a) Expenses. The Company will pay or cause to be paid all expenses incident to the performance of their obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and of each amendment thereto, (ii) the preparation, printing and delivery to the Underwriters of this Agreement, any Agreement among Underwriters and such other documents as may be required in connection with the offering, purchase, sale, issuance or delivery of the Securities, (iii) the preparation, issuance and delivery of the certificates for the Securities to the Underwriters, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Securities to the Underwriters, (iv) the fees and disbursements of the Company’s counsel, accountants and other advisors, (v) the qualification of the Securities under securities laws in accordance with the provisions of Section 3(f) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection therewith and in connection with the preparation of the Blue Sky Survey and any supplement thereto, (vi) the printing and delivery to the Underwriters of copies of each preliminary prospectus, any Permitted Free Writing Prospectus and of the Prospectus and any amendments or supplements thereto and any costs associated with electronic delivery of any of the foregoing by the Underwriters to investors, (vii) the preparation, printing and delivery to the Underwriters of copies of the Blue Sky Survey and any supplement thereto, (viii) the fees and expenses of any transfer agent or registrar for the Securities, (ix) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the Securities, including without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations, travel and lodging expenses of the representatives and officers of the Company and any such consultants, and the cost of aircraft and other transportation chartered in connection with the road show, (x) the fees and expenses incurred in connection the inclusion of the Securities in the NASDAQ Global Select Market, and (xi) the costs and expenses (including, without limitation, any damages or other amounts payable in connection with legal or contractual liability) associated with the reforming of any contracts for sale of the Securities made by the Underwriter caused by a breach of the representation contained in the third or fourth paragraph of Section 1(a)(i).

(b) Termination of Agreement. If this Agreement is terminated by the Representatives in accordance with the provisions of Section 5, Section 9(a)(i) or Section 9(a)(iii) (solely with respect to the first part of Section 9(a)(iii) relating to trading in any securities of the Company) hereof, the Company shall reimburse the Underwriters for all of their

out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters.

SECTION 5. Conditions of Underwriters’ Obligations. The obligations of the several Underwriters hereunder are subject to the accuracy of the representations and warranties of the Company contained in Section 1 hereof or in certificates of any officer of the Company or any Subsidiary of the Company delivered pursuant to the provisions hereof, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions:

(a) Effectiveness of Registration Statement and Filing of Prospectus. The Registration Statement has become effective and at Closing Time no stop order suspending the effectiveness of the Registration Statement shall have been issued under the 1933 Act or proceedings therefore initiated or threatened by the Commission, and any request on the part of the Commission for additional information shall have been complied with to the reasonable satisfaction of counsel to the Underwriters. A prospectus containing the Rule 430B Information shall have been filed with the Commission in the manner and within the time period required by Rule 424(b) without reliance on Rule 424(b)(8) (or a post-effective amendment providing such information shall have been filed and become effective in accordance with the requirements of Rule 430B).

(b) Opinion of Outside Counsel for the Company; Opinion of In-House Counsel for the Company. At Closing Time, the Representatives shall have received (i) the favorable opinion, dated as of Closing Time, of Dorsey & Whitney LLP, counsel for the Company, in form and substance satisfactory to counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters to the effect set forth in Exhibit A-1 hereto and to such further effect as counsel to the Underwriters may reasonably request and (ii) the favorable opinion, dated as of Closing Time, of George A. Koeck, General Counsel of the Company, in form and substance satisfactory to counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters to the effect set forth in Exhibit A-2 hereto and to such further effect as counsel to the Underwriters may reasonably request.

(c) Opinion of Counsel for Underwriters. At Closing Time, the Representatives shall have received the favorable opinion, dated as of Closing Time, of Winston & Strawn LLP, counsel for the Underwriters, together with signed or reproduced copies of such letter for each of the other Underwriters with respect to the matters set forth in clauses (i), (v), (vii) through (ix), inclusive, (xi), (xii) (solely as to the information in the Prospectus under “Description of Capital Stock—Common Stock”) and the paragraph immediately following clause (xvi) of Exhibit A-1 hereto. In giving such opinion such counsel may rely, as to all matters governed by the laws of jurisdictions other than the law of the State of New York and the federal law of the United States and the General Corporation Law of the State of Delaware, upon the opinions of counsel satisfactory to the Representatives. Such counsel may also state that, insofar as such opinion involves factual matters, they have relied, to the extent they deem proper, upon certificates of officers of the Company and its Subsidiaries and certificates of public officials.

(d) Officers’ Certificate. At Closing Time, there shall not have been, since the date hereof, since the Applicable Time or since the respective dates as of which information is given in the Prospectus or the General Disclosure Package, any material adverse change or any development involving a prospective material adverse change, in the business, properties, management, financial condition or results of operations of the Company and its Subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, and the Representatives shall have received a certificate of the Chief Executive Officer of the Company and of the Chief Financial Officer of the Company, dated as of Closing Time, to the effect that (i) there has been no such material adverse change, (ii) the representations and warranties in Section 1(a) hereof are true and correct with the same force and effect as though expressly made at and as of Closing Time, (iii) the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied at or prior to Closing Time, and (iv) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or are pending or, to their knowledge, contemplated by the Commission.

(e) Accountant’s Comfort Letter. At the time of the execution of this Agreement, the Representatives shall have received from Deloitte & Touche LLP a letter dated such date, in form and substance satisfactory to the Representatives, together with signed or reproduced copies of such letter for each of the other Underwriters containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement and the Prospectus.

(f) Bring-down Comfort Letter. At Closing Time, the Representatives shall have received from Deloitte & Touche LLP a letter, dated as of Closing Time, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (e) of this Section, except that the specified date referred to shall be a date not more than three business days prior to Closing Time.

(g) Approval of Listing. At Closing Time, the Securities shall have been approved for inclusion in the NASDAQ Global Select Market, subject only to official notice of issuance.

(h) Lock-up Agreements. At the date of this Agreement, the Representatives shall have received an agreement substantially in the form of Exhibit B hereto signed by the persons listed on Schedule F hereto.

(i) Maintenance of Rating. Since the execution of this Agreement, there shall not have been any decrease in the rating of any of the Company’s securities by any “nationally recognized statistical rating organization” (as defined for purposes of Rule 436(g) under the 1933 Act) or any notice given of any intended or potential decrease in any such rating or of a possible change in any such rating that does not indicate the direction of the possible change.

(j) Conditions to Purchase of Option Securities. In the event that the Underwriters exercise their option provided in Section 2(b) hereof to purchase all or any portion of the Option Securities, the representations and warranties of the Company contained herein and the statements in any certificates furnished by the Company and any Subsidiary of the Company

hereunder shall be true and correct as of each Date of Delivery and, at the relevant Date of Delivery, the Representatives shall have received:

(i) Officers’ Certificate. A certificate, dated such Date of Delivery, of the Chief Executive Officer of the Company and of the Chief Financial Officer of the Company confirming that the certificate delivered at the Closing Time pursuant to Section 5(d) hereof remains true and correct as of such Date of Delivery.

(iii) Opinion of Counsel for Company and General Counsel Opinion. The favorable opinion of Dorsey & Whitney, LLP, counsel for the Company, and the favorable opinion of George A. Koeck, General Counsel of the Company, each in form and substance satisfactory to counsel for the Underwriters, dated such Date of Delivery, relating to the Option Securities to be purchased on such Date of Delivery and otherwise to the same effect as the respective opinions required by Section 5(b) hereof.

(v) Opinion of Counsel for Underwriters. The favorable opinion of Winston & Strawn LLP, counsel for the Underwriters, dated such Date of Delivery, relating to the Option Securities to be purchased on such Date of Delivery and otherwise to the same effect as the opinion required by Section 5(c) hereof.

(vi) Bring-down Comfort Letter. A letter from Deloitte & Touche LLP, in form and substance satisfactory to the Representatives and dated such Date of Delivery, substantially in the same form and substance as the letter furnished to the Representatives pursuant to Section 5(f) hereof, except that the “specified date” in the letter furnished pursuant to this paragraph shall be a date not more than five days prior to such Date of Delivery.

(k) Additional Documents. At Closing Time and at each Date of Delivery counsel for the Underwriters shall have been furnished with such documents and opinions as they may require for the purpose of enabling them to pass upon the issuance and sale of the Securities as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Securities as herein contemplated shall be satisfactory in form and substance to the Representatives and counsel for the Underwriters.

(l) Termination of Agreement. If any condition specified in this Section shall not have been fulfilled when and as required to be fulfilled, this Agreement, or, in the case of any condition to the purchase of Option Securities on a Date of Delivery which is after the Closing Time, the obligations of the several Underwriters to purchase the relevant Option Securities, may be terminated by the Representatives by notice to the Company at any time at or prior to Closing Time or such Date of Delivery, as the case may be, and such termination shall be without liability of any party to any other party except as provided in Section 4 and except that Sections 1, 6, 7 and 8 shall survive any such termination and remain in full force and effect.

SECTION 6. Indemnification.

(a) Indemnification of Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its affiliates, as such term is defined in Rule 501(b) under the 1933 Act (each, an “Affiliate”), its selling agents and each person, if any, who controls any Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 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 Registration Statement (or any amendment thereto), including the Rule 430B Information, 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 included in any preliminary prospectus, any Issuer Free Writing Prospectus or the Prospectus (or any amendment or supplement thereto), 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 any 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; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company;

(iii) against any and all expense whatsoever, as incurred (including the fees and disbursements of counsel chosen by Merrill Lynch), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, 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 (i) or (ii) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through Merrill Lynch expressly for use in the Registration Statement (or any amendment thereto), including the Rule 430B Information, or any preliminary prospectus, any Issuer Free Writing Prospectus or the Prospectus (or any amendment or supplement thereto).

(b) Indemnification of Company, Directors and Officers. Each Underwriter severally agrees to indemnify and hold harmless the Company, its directors, each of its officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act against any and all loss,

liability, claim, damage and expense described in the indemnity contained in Section 6(a), as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), including the Rule 430B Information or any preliminary prospectus, any Issuer Free Writing Prospectus or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information furnished to the Company by such Underwriter through Merrill Lynch expressly for use therein.

(c) Actions against Parties; Notification. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) above, counsel to the indemnified parties shall be selected by Merrill Lynch, and, in the case of parties indemnified pursuant to Section 6(b) above, counsel to the indemnified parties shall be selected by the Company. An indemnifying party may participate at its own expense in the defense of any such action; provided, however, that counsel to the indemnifying party shall not (except with the consent of the indemnified party) also be counsel to the indemnified party. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d) Settlement without Consent if Failure to Reimburse. If at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) effected without its written consent if (i) such settlement is entered into more than 60 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

SECTION 7. Contribution. If the indemnification provided for in Section 6 hereof is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party

shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (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 pursuant to this Agreement or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such 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 of the Underwriters on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, 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 hand in connection with the offering of the Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company and the total underwriting discount received by the Underwriters, in each case as set forth on the cover of the Prospectus bear to the aggregate initial public offering price of the Securities as set forth on the cover of the Prospectus.

The relative fault of the Company on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or 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 7 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

Notwithstanding the provisions of this Section 7, no Underwriter shall 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 which such Underwriter has otherwise been required to pay by reason of any 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 1933 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

For purposes of this Section 7, each person, if any, who controls an Underwriter within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act and each Underwriter’s Affiliates and selling agents shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company. The Underwriters’ respective obligations to contribute pursuant to this Section 7 are several in proportion to the number of Initial Securities set forth opposite their respective names in Schedule A hereto and not joint.

SECTION 8. Representations, Warranties and Agreements to Survive. All representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company or any of its Subsidiaries submitted pursuant hereto, shall remain operative and in full force and effect regardless of (i) any investigation made by or on behalf of any Underwriter or its Affiliates or selling agents, any person controlling any Underwriter, its officers or directors or any person controlling the Company and (ii) delivery of and payment for the Securities.

SECTION 9. Termination of Agreement.

(a) Termination; General. The Representatives may terminate this Agreement, by notice to the Company at any time at or prior to Closing Time (i) if there has been, since the time of execution of this Agreement or since the respective dates as of which information is given in the Prospectus (exclusive of any supplement thereto) or General Disclosure Package, any material adverse change or any development involving a prospective material adverse change, in the business, properties, management, financial condition or results of operations of the Company and its Subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, or (ii) if there has occurred any material adverse change in the financial markets in the United States or the international financial markets, any outbreak of hostilities or escalation thereof or other 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 Representatives, impracticable or inadvisable to market the Securities or to enforce contracts for the sale of the Securities, or (iii) if trading in any securities of the Company has been suspended or materially limited by the Commission or the NASDAQ Global Select Market, or if trading generally on the American Stock Exchange or the New York Stock Exchange or in the NASDAQ Global Select Market has been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required, by any of said exchanges or by such system or by order of the Commission, the National Association of Securities Dealers, Inc. or any other governmental authority, or (iv) a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States, or (v) if a banking moratorium has been declared by either Federal or New York authorities.

(b) Liabilities. If this Agreement is terminated pursuant to this Section, such termination shall be without liability of any party to any other party except as provided in Section 4 hereof, and provided further that Sections 1, 6, 7 and 8 shall survive such termination and remain in full force and effect.

SECTION 10. Default by One or More of the Underwriters. If one or more of the Underwriters shall fail at Closing Time or a Date of Delivery to purchase the Securities which it or they are obligated to purchase under this Agreement (the “Defaulted Securities”), the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Securities in such amounts as may be agreed upon and upon the terms herein set forth; if, however, the Representatives shall not have completed such arrangements within such 24-hour period, then:

(i) if the number of Defaulted Securities does not exceed 10% of the number of Securities to be purchased on such date, each of the non-defaulting Underwriters shall be obligated, severally and not jointly, to purchase the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of all non-defaulting Underwriters, or

(ii) if the number of Defaulted Securities exceeds 10% of the number of Securities to be purchased on such date, this Agreement or, with respect to any Date of Delivery which occurs after the Closing Time, the obligation of the Underwriters to purchase and of the Company to sell the Option Securities to be purchased and sold on such Date of Delivery, shall terminate without liability on the part of any non-defaulting Underwriter.

No action taken pursuant to this Section shall relieve any defaulting Underwriter from liability in respect of its default.

In the event of any such default which does not result in a termination of this Agreement or, in the case of a Date of Delivery which is after the Closing Time, which does not result in a termination of the obligation of the Underwriters to purchase and the Company to sell the relevant Option Securities, as the case may be, either (i) the Representatives or (ii) the Company shall have the right to postpone Closing Time or the relevant Date of Delivery, as the case may be, for a period not exceeding seven days in order to effect any required changes in the Registration Statement or Prospectus or in any other documents or arrangements. As used herein, the term “Underwriter” includes any person substituted for an Underwriter under this Section 10.

SECTION 11. Tax Disclosure. Notwithstanding any other provision of this Agreement, from the commencement of discussions with respect to the transactions contemplated hereby, the Company (and each employee, representative or other agent of the Company) may disclose to any and all persons, without limitation of any kind, the tax treatment and tax structure (as such terms are used in Sections 6011, 6111 and 6112 of the United States Internal Revenue Code of 1986, as amended, and the Treasury Regulations promulgated thereunder) of the transactions contemplated by this Agreement and all materials of any kind (including opinions or other tax analyses) that are provided relating to such tax treatment and tax structure.

SECTION 12. Notices. 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 directed to the Representatives

at 4 World Financial Center, New York, New York 10080, attention of Global Origination Counsel Group; notices to the Company shall be directed to it at 215 South Cascade Street, Box 496, Fergus Falls, Minnesota 56538, attention of General Counsel.

SECTION 13. No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) the purchase and sale of the Securities pursuant to this Agreement, including the determination of the public offering price of the Securities and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the several Underwriters, on the other hand, (b) in connection with the offering contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company, or its respective stockholders, creditors, employees or any other party, (c) no Underwriter has assumed or will assume an advisory or fiduciary responsibility in favor of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (d) the Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (e) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own respective legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

SECTION 14. Integration. This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company and the Underwriters, or any of them, with respect to the subject matter hereof.

SECTION 15. Parties. This Agreement shall each inure to the benefit of and be binding upon the Underwriters and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Underwriters and the Company and their respective successors and the controlling persons and officers and directors referred to in Sections 6 and 7 and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Underwriters and the Company and their respective successors, and said controlling persons and officers and directors and their heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Securities from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

SECTION 16. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

SECTION 17. TIME. TIME SHALL BE OF THE ESSENCE OF THIS AGREEMENT. EXCEPT AS OTHERWISE SET FORTH HEREIN, SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument, along with all counterparts, will become a binding agreement among the Underwriters and the Company in accordance with its terms.


	Very truly yours, OTTER TAIL CORPORATION
	By:	/s/ George A. Koeck
		George A. Koeck
		General Counsel and Corporate Secretary

CONFIRMED AND ACCEPTED,
as of the date first above written:

MERRILL LYNCH & CO.
MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
ROBERT W. BAIRD & CO. INCORPORATED
J.P. MORGAN SECURITIES INC.
BANC OF AMERICA SECURITIES LLC
WELLS FARGO SECURITIES, LLC
KEYBANC CAPITAL MARKETS INC.

By: MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED


By		/s/ Partho Sanyal Authorized Signatory

For themselves and as Representatives of the other Underwriters named in Schedule A hereto.

SCHEDULE G

Subsidiaries


Company		State of Organization
Otter Tail Energy Services Company, Inc.		Minnesota
Overland Mechanical Services, Inc.		Minnesota
Green Hills Energy, LLC		Minnesota
Sheridan Ridge I, LLC		Minnesota
Sheridan Ridge II, LLC		Minnesota
Otter Tail Assurance Limited		Cayman Islands
Varistar Corporation*		Minnesota
Northern Pipe Products, Inc.*		North Dakota
Vinyltech Corporation*		Arizona
T.O. Plastics, Inc.*		Minnesota
St. George Steel Fabrication, Inc.		Utah
DMI Industries, Inc.*		North Dakota
DMI Canada, Inc.		Ontario, Canada
BTD Manufacturing, Inc.*		Minnesota
Miller Welding & Iron Works, Inc.		Minnesota
ShoreMaster, Inc.*		Minnesota
Galva Foam Marine Industries, Inc.		Missouri
Shoreline Industries, Inc.		Minnesota
Aviva Sports, Inc.		Minnesota
ShoreMaster Costa Rica, Limitada		Costa Rica
DMS Health Technologies, Inc.*		North Dakota
DMS Imaging, Inc.*		North Dakota
DMS Imaging Partners, LLC		Delaware
DMS Imaging Partners II, LLC		Delaware
DMS Leasing Corporation		North Dakota
Midwest Construction Services, Inc.*		Minnesota
Aerial Contractors, Inc.		North Dakota
Moorhead Electric, Inc.		Minnesota
Lynk3 Technologies, Inc		Minnesota
AC Equipment, Inc.		Minnesota
Ventus Energy Systems, Inc.		Minnesota
Foley Company*		Missouri
Chassis Liner Corporation		Minnesota
E. W. Wylie Corporation*		North Dakota
Idaho Pacific Holdings, Inc.*		Delaware
Idaho-Pacific Corporation		Idaho
Idaho-Pacific Colorado Corporation		Delaware
AWI Acquisition Company Limited		Prince Edward Island, Canada
AgraWest Investments Limited		Prince Edward Island, Canada


*		Significant Subsidiary

Schedule G

EXHIBIT A-1

FORM OF OPINION OF COMPANY’S OUTSIDE COUNSEL
TO BE DELIVERED PURSUANT TO SECTION 5(b)

(i) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Minnesota.

(ii) The Company has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Prospectus and to enter into and perform its obligations under the Purchase Agreement.

(iii) The Company is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect.

(iv) The authorized capital stock of the Company is as set forth in the Prospectus.

(v) The Securities to be purchased by the Underwriters from the Company have been duly authorized for issuance and sale to the Underwriters pursuant to the Purchase Agreement and, when issued and delivered by the Company pursuant to the Purchase Agreement against payment of the consideration set forth in the Purchase Agreement, will be validly issued and fully paid and non-assessable and no holder of the Securities is or will be subject to personal liability by reason of being such a holder.

(vi) The issuance and sale of the Securities by the Company is not subject to any statutory preemptive right, or, to our knowledge, any contractual preemptive right, resale right, right of first refusal or other similar rights of any security holder of the Company.

(vii) The Purchase Agreement has been duly authorized, executed and delivered by the Company.

(viii) The Registration Statement has become effective under the 1933 Act; any required filing of each prospectus relating to the Securities (including the Prospectus) pursuant to Rule 424(b) has been made in the manner and within the time period required by Rule 424(b) (without reference to Rule 424(b)(8)); any required filing of each Issuer Free Writing Prospectus pursuant to Rule 433 has been made in the manner and within the time period required by Rule 433(d); and, to our knowledge, no stop order suspending the effectiveness of the Registration Statement has been issued under the 1933 Act and no proceedings for that purpose have been instituted or are pending or threatened by the Commission.

(ix) The Registration Statement, including without limitation the Rule 430B Information, the Prospectus, excluding the documents incorporated by reference therein, and each amendment or supplement to the Registration Statement and the Prospectus, excluding the

A-1

documents incorporated by reference therein, as of their respective effective or issue dates (including without limitation each deemed effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations), other than the financial statements and supporting schedules and other financial data included therein or omitted therefrom and the Trustee’s Statement of Eligibility on Form T-1 (the “Form T-1”), as to which we need express no opinion, complied as to form in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations.

(x) The documents incorporated by reference in the Prospectus (other than the financial statements and supporting schedules and other financial data included therein or omitted therefrom, as to which we need express no opinion), as of the dates they were filed with the Commission, complied as to form in all material respects with the requirements of the 1934 Act and the rules and regulations of the Commission thereunder.

(xi) The form of certificate used to evidence the Securities complies in all material respects with all applicable statutory requirements, with any applicable requirements of the charter and by-laws of the Company and the requirements of The NASDAQ Stock Market LLC.

(xii) The information in the Prospectus under “Description of Common Shares” and “Description of Cumulative Preferred Shares” and in the Registration Statement under Item 15, to the extent that it constitutes matters of law, summaries of legal matters, the Company’s charter and bylaws or legal proceedings, or legal conclusions, has been reviewed by us and is accurate in all material respects.

(xiii) No filing with, or authorization, approval, consent, license, order, registration, qualification or decree of, any court or governmental authority or agency, domestic or foreign (other than (a) under the 1933 Act and the 1933 Act Regulations and from the Minnesota Public Utilities Commission, which have been obtained, or (b) as may be required under the securities or blue sky laws of the various states or foreign jurisdictions or under the rules and regulations of the National Association of Securities Dealers, Inc., as to which we need express no opinion) is necessary or required in connection with the due authorization, execution and delivery of the Purchase Agreement or for the offering, issuance, sale or delivery of the Securities.

(xiv) The execution, delivery and performance of the Purchase Agreement and the consummation of the transactions contemplated in the Purchase Agreement and in the Registration Statement (including the issuance and sale of the Securities and the use of the proceeds from the sale of the Securities as described in the Prospectus under the caption “Use Of Proceeds”) and compliance by the Company with its obligations under the Purchase Agreement do not and will not, whether with or without the giving of notice or lapse of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined in Section 1(a)(xi) of the Purchase Agreement) under or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or any other agreement or instrument, known to us, to which the Company is a party or by which it may be bound, or to which any of the property or assets of the Company is subject (except for such conflicts,

A-2

breaches, defaults or Repayment Events or liens, charges or encumbrances that would not have a Material Adverse Effect), nor will such action result in any violation of the provisions of the charter or by-laws of the Company, or any applicable law, statute, rule, regulation, judgment, order, writ or decree (other than any federal, state or foreign securities or Blue Sky laws, statutes, rules or regulations) known to us, of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company or any of its respective properties, assets or operations.

(xv) The Company is not, and upon the issuance and sale of the Securities as herein contemplated and the application of the net proceeds therefrom as described in the Prospectus will not be an “investment company” as such term is defined in the 1940 Act, as amended.

(xvi) At the time of effectiveness of the Registration Statement, the Company was eligible to use Form S-3 pursuant to the standards for that Form prior to October 21, 1992.

Nothing has come to our attention that would lead us to believe that the Original Registration Statement or any amendment thereto (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom and the Form T-1, as to which we need make no statement), at the time such Original Registration Statement or any such amendment became effective, 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; that the Registration Statement, including the Rule 430B Information (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom and the Form T-1, as to which we need make no statement), at each deemed effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations, 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; or that the Prospectus or any amendment or supplement thereto (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom, as to which we need make no statement), at the time the Prospectus was issued, at the time any such amended or supplemented prospectus was issued or at the Closing Time, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. In addition, nothing has come to our attention that would lead us to believe that the General Disclosure Package, other than the financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom, as to which we need make no statement, as of the Applicable Time, 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. With respect to statements contained in the General Disclosure Package, any statement contained in any of the constituent documents shall be deemed to be modified or superseded to the extent that any information contained in subsequent constituent documents modifies or replaces such statement.

Our opinions expressed above are limited to the laws of the State of Minnesota and the federal laws of the United States of America.

A-3

EXHIBIT A-2

FORM OF OPINION OF COMPANY’S GENERAL COUNSEL
TO BE DELIVERED PURSUANT TO SECTION 5(b)

(i) The shares of issued and outstanding capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable; and none of the outstanding shares of capital stock of the Company were issued in violation of any statutory preemptive right, or, to my knowledge, any contractual preemptive right, resale right, right of first refusal or other similar rights of any security holder of the Company.

(ii) Each Significant Subsidiary has been duly incorporated and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Prospectus and is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure so to qualify or to be in good standing would not result in a Material Adverse Effect; except as otherwise disclosed in the Registration Statement, all of the issued and outstanding shares of capital stock of each Significant Subsidiary have been duly authorized and validly issued, are fully paid and non-assessable and, to my knowledge, are owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity; and to my knowledge, none of the outstanding shares of capital stock of any Significant Subsidiary were issued in violation of the preemptive or similar rights of any security holder of such Significant Subsidiary.

(iii) To the best of my knowledge, except as disclosed in the Prospectus, there is not pending or threatened any action, suit, proceeding, inquiry or investigation, to which the Company or any Subsidiary is a party, or to which the property of the Company or any Subsidiary is subject, before or brought by any court or governmental agency or body, domestic or foreign, which would reasonably be expected to result in a Material Adverse Effect, or which would reasonably be expected to materially and adversely affect the properties or assets thereof or the consummation of the transactions contemplated in the Purchase Agreement or the performance by the Company of its obligations thereunder.

(iv) All descriptions in the Registration Statement of contracts and other documents to which the Company or its Significant Subsidiaries are a party are accurate in all material respects; to my knowledge, there are no franchises, contracts, indentures, mortgages, loan agreements, notes, leases or other instruments required to be described or referred to in the Registration Statement or to be filed as exhibits to the Registration Statement or to the documents incorporated by reference to the Registration Statement other than those described or referred to therein or filed or incorporated by reference as exhibits thereto.

(v) The execution, delivery and performance of the Purchase Agreement and the consummation of the transactions contemplated in the Purchase Agreement and in the Registration Statement (including the issuance and sale of the Securities and the use of the

A-3

proceeds from the sale of the Securities as described in the Prospectus under the caption “Use Of Proceeds”) and compliance by the Company with its obligations under the Purchase Agreement do not and will not, whether with or without the giving of notice or lapse of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined in Section 1(a)(xi) of the Purchase Agreement) under or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any Significant Subsidiary pursuant to any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or any other agreement or instrument, known to me, to which the Company or any Significant Subsidiary is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any Significant Subsidiary is subject (except for such conflicts, breaches, defaults or Repayment Events or liens, charges or encumbrances that would not have a Material Adverse Effect), nor will such action result in any violation of the provisions of the charter or by-laws of the Company or any Significant Subsidiary, or any applicable law, statute, rule, regulation, judgment, order, writ or decree (other than any federal, state or foreign securities or Blue Sky laws, statutes, rules or regulations) known to me, of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company or any Significant Subsidiary or any of their respective properties, assets or operations.

Nothing has come to my attention that would lead me to believe that the Original Registration Statement or any amendment thereto (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom and the Form T-1, as to which I make no statement), at the time such Original Registration Statement or any such amendment became effective, 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; that the Registration Statement, including the Rule 430B Information (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom and the Form T-1, as to which I make no statement), at each deemed effective date with respect to the Underwriters pursuant to Rule 430B(f)(2) of the 1933 Act Regulations, 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; or that the Prospectus or any amendment or supplement thereto (except for financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom, as to which I make no statement), at the time the Prospectus was issued, at the time any such amended or supplemented prospectus was issued or at the Closing Time, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. In addition, nothing has come to my attention that would lead me to believe that the General Disclosure Package, other than the financial statements and schedules and other financial data included or incorporated by reference therein or omitted therefrom, as to which I make no statement, as of the Applicable Time, 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. With respect to statements contained in the General Disclosure Package, any statement contained in any of the constituent documents shall be deemed to be modified or superseded to the extent that any information contained in subsequent constituent documents modifies or replaces such statement.

A-3

EXHIBIT B

September ___, 2008

as Representatives of the several Underwriters
to be named in the within-mentioned Purchase Agreement

c/o Merrill Lynch & Co.
Merrill Lynch, Pierce, Fenner & Smith Incorporated
4 World Financial Center
New York, New York 10080

Re: Proposed Public Offering by Otter Tail Corporation

Ladies and Gentlemen:

The undersigned, a director or officer of Otter Tail Corporation, a Minnesota corporation (the “Company”), understands that Merrill Lynch & Co., Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”) and Robert W. Baird & Co. Incorporated, J.P. Morgan Securities Inc., Banc of America Securities LLC, Wells Fargo Securities, LLC and KeyBanc Capital Markets Inc. proposes to enter into a Purchase Agreement (the “Purchase Agreement”) with the Company providing for the public offering (the “Offering”) of shares (the “Securities”) of the Company’s common shares, par value $5.00 per share (the “Common Stock”). In recognition of the benefit that such an offering will confer upon the undersigned as a stockholder director, officer, employee and/or stockholder of the Company, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with each underwriter to be named in the Purchase Agreement that, during a period of 90 days from the date of the Purchase Agreement, the undersigned will not, without the prior written consent of Merrill Lynch, directly or indirectly, (i) 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 for the sale of, or otherwise dispose of or transfer any shares of the Company’s Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition, or file, or cause to be filed, any registration statement under the Securities Act of 1933, as amended, with respect to any of the foregoing (collectively, the “Lock-Up Securities”) or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Lock-Up Securities, whether any such swap or transaction is to be settled by delivery of Common Stock or other securities, in cash or otherwise.

B-1

Notwithstanding the foregoing, and subject to the conditions below, the undersigned may transfer the Lock-Up Securities without the prior written consent of Merrill Lynch (A) as a bona fide gift or gifts; or (B) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for purposes of this lock-up agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin); or (C) as a distribution to limited partners or stockholders of the undersigned; provided that (1) Merrill Lynch receives a signed lock-up agreement for the balance of the lockup period from each donee, trustee, distributee, or transferee, as the case may be, (2) any such transfer shall not involve a disposition for value, (3) such transfers are not required to be reported in any public report or filing with the Securities and Exchange Commission, or otherwise and (4) the undersigned does not otherwise voluntarily effect any public filing or report regarding such transfers. This lock-up agreement shall not apply bona fide gifts by the undersigned of Lock-Up Securities to charities not in excess of 500 shares of Common Stock in the aggregate.

Notwithstanding the foregoing, if:

(1) during the last 17 days of the 90-day lock-up period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or

(2) prior to the expiration of the 90-day lock-up period, the Company announces that it will release earnings results or becomes aware that material news or a material event will occur during the 16-day period beginning on the last day of the 90-day lock-up period,

the restrictions imposed by this lock-up agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event, as applicable, unless Merrill Lynch waives, in writing, such extension.

The undersigned hereby acknowledges and agrees that written notice of any extension of the 90-day lock-up period pursuant to the previous paragraph will be delivered by Merrill Lynch to the Company (in accordance with Section 12 of the Purchase Agreement) and that any such notice properly delivered will be deemed to have been given to, and received by, the undersigned. The undersigned further agrees that, prior to engaging in any transaction or taking any other action that is subject to the terms of this lock-up agreement during the period from the date of this lock-up agreement to and including the 34^th day following the expiration of the 90-day lock-up period, it will give notice thereof to the Company and will not consummate such transaction or take any such action unless it has received written confirmation from the Company that the 90-day lock-up period (as may have been extended pursuant to the previous paragraph) has expired.

The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the Lock-Up Securities except in compliance with the foregoing restrictions.

If (i) the Company notifies the undersigned in writing that it does not intend to proceed with the Offering, or (ii) for any reason the Purchase Agreement shall be terminated prior to the

B-2


	Number of Initial		Maximum Number of Option
	Securities to be Sold		Securities to Be Sold
OTTER TAIL CORPORATION		4,500,000		675,000


	Number of
	Initial
Name of Underwriter	Securities
Merrill Lynch, Pierce, Fenner & Smith Incorporated		2,250,000
Robert W. Baird & Co. Incorporated		787,500
J.P. Morgan Securities Inc.		787,500
Banc of America Securities LLC		315,000
Wells Fargo Securities, LLC		225,000
KeyBanc Capital Markets Inc.		135,000


TOTAL		4,500,000

1.		The public offering price per share for the Securities is $30.00.

2.		The number of shares of the Securities purchased by the Underwriters is 4,500,000.

1.		Issuer Free Writing Prospectus filed on September 15, 2008

2.		Issuer Free Writing Prospectus to be filed on September 19, 2008