485BPOS

AS FILED ELECTRONICALLY WITH THE SECURITIES AND EXCHANGE COMMISSION ON

OCTOBER 7, 2011

SECURITIES ACT FILE NO. 333-170630

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-14

REGISTRATION STATEMENT

UNDER THE SECURITIES ACT OF 1933	x
Pre-Effective Amendment No.	¨
Post-Effective Amendment No. 1	x

COLUMBIA ACORN TRUST

(Exact Name of Registrant as Specified in Charter)

227 West Monroe Street, Suite 3000

Chicago, Illinois 60606

(Address of Principal Executive Offices) (Zip Code)

312.634.9200

(Registrant’s Area Code and Telephone Number)

Charles P. McQuaid Columbia Acorn Trust 227 West Monroe Street, Suite 3000 Chicago, Illinois 60606	Scott R. Plummer, Esq. c/o Columbia Management Investment Advisers, LLC 225 Franklin Street Boston, MA 02110	Mary C. Moynihan Perkins Coie LLP 700 13th Street, N.W., Suite 600 Washington, D.C. 20005
	(Name and Address of Agent for Service)

With a copy to:

Brian D. McCabe, Esq.

Ropes & Gray LLP

Prudential Tower

800 Boylston Street

Boston, Massachusetts 02199

It is proposed that this filing will become effective immediately upon filing pursuant to paragraph (b) of Rule 485 under the Securities Act of 1933, as amended.

There have been no changes to the proxy statement/prospectus or statement of additional information as filed by the Registrant pursuant to Rule 497(b) (File No. 333-170630) with the Commission on March 14, 2011 (Accession No. 0001193125-11-065197).

COLUMBIA ACORN TRUST

PART C

OTHER INFORMATION

PART C. OTHER INFORMATION

Item 15. Indemnification

Article VIII of the Agreement and Declaration of Trust of the Registrant (exhibit a.1) provides in effect that Registrant shall provide certain indemnification of its trustees and officers. In accordance with Section 17(h) of the Investment Company Act of 1940, as amended, that provision shall not protect any person against any liability to the Registrant or its shareholders to which he would otherwise be subject by reason of willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of his office.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended (the “Securities Act”), may be permitted to trustees, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a trustee, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such trustee, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

The Registrant has entered into Indemnification Agreements with each of the independent trustees and its chief compliance officer (“CCO”) which provide that the Registrant shall indemnify and advance expenses to the independent trustees and CCO as provided in the Indemnification Agreements and otherwise to the fullest extent permitted by applicable law. The Registrant will indemnify the independent trustees and the CCO for and against any and all judgments, penalties, fines and amounts paid in settlement, and all expenses actually and reasonably incurred by the independent trustees and/or the CCO in connection with a proceeding to which he or she is a party to by reason of his or her position as an independent trustee or CCO. The Registrant will not indemnify the independent trustees or the CCO for monetary settlements or judgments relating to insider trading, disgorgements of profits pursuant to Section 16(b) of the Securities Exchange Act of 1934, or any liability to the Registrant or its shareholders with respect to a final adjudication that an action or omission by an independent trustee or the CCO (i) was committed in bad faith, was the result of active or deliberate dishonesty, involved actual receipt by the trustee of an improper benefit in money, property or services, or in the case of a criminal proceeding, involved reasonable cause for the trustee or the CCO to believe that the act or omission was unlawful, or (ii) involved the trustee’s or CCO’s engagement in willful misfeasance, bad faith, gross negligence or reckless disregard of his or her duties.

The Registrant, its trustees and officers, its investment adviser and persons affiliated with them are insured under policies of insurance maintained by the Registrant and its investment adviser, within the limits and subject to the limitations of the policies, against certain expenses in connection with the defense of actions, suits or proceedings, and certain liabilities that might be imposed as a result of such actions, suits or proceedings, to which they are parties by reason of being or having been such trustees or officers. The policies expressly exclude coverage for any trustee or officer whose personal dishonesty, fraudulent breach of trust, lack of good faith, or intention to deceive or defraud has been finally adjudicated or may be established or who willfully fails to act prudently.

Item 16. Exhibits

Note: As used herein, the term “Post-effective Amendment” refers to a post-effective amendment to the registration statement of Registrant or its predecessor, The Acorn Fund, Inc., under the Securities Act of 1933 on form S-5, N-1 or N-1A, no. 2-34223.

(1) (a) Agreement and Declaration of Trust. (1)

(1) (b) Amendment No. 1 to Agreement and Declaration of Trust. (3)

(1) (c) Amendment No. 2 to Agreement and Declaration of Trust. (4)

(2) By-Laws dated September 28, 2004, as amended through December 17, 2009. (9)

(3) Not applicable.

(4) Agreement and Plan of Reorganization is filed electronically herewith.

(5) Not applicable.

(6) (a) Organizational Expenses Agreement between Acorn Investment Trust (now known as Columbia Acorn Trust) and Wanger Asset Management, L.P. (now known as Columbia Wanger Asset Management, LLC), dated September 3, 1996. (2)

(6) (b) Investment Advisory Agreement between Columbia Acorn Trust and Columbia Wanger Asset Management, LLC dated May 27, 2010, Schedules A and B last amended June 8, 2011. (10)

(6) (c) Administrative Services Agreement between Columbia Acorn Trust and Columbia Wanger Asset Management, LLC dated May 1, 2010, Schedule A last amended June 8, 2011. (10)

(7) (a) Distribution Agreement between Columbia Acorn Trust and Columbia Management Investment Distributors, Inc. dated May 1, 2010, Schedules I and II last amended June 8, 2011. (10)

(7) (b) Amendment dated April 12, 2011 to the Distribution Agreement between Columbia Acorn Trust and Columbia Management Investment Distributors, Inc. dated May 1, 2010. (10)

(8) Not Applicable.

(9) Custody Agreement among JPMorgan Chase Bank, N.A., Columbia Acorn Trust and Wanger Advisors Trust dated December 15, 2010, effective July 22, 2011, with Addendums dated July 14, 2011. (10)

(10) (a) Plan of Distribution pursuant to Rule 12b-1 last approved by the Board of Trustees June 8, 2011. (10)

(10) (b) Rule 12b-1 Plan Implementing Agreement last approved by the Board of Trustees March 2, 2011. (10)

(10) (c) Amended and Restated Plan pursuant to Rule 18f-3(d) effective May 1, 2010, last approved by the Board of Trustees December 15, 2010. (10)

(11) Opinion and consent of counsel as to the legality of the securities being registered. (8)

(12) Opinion of counsel regarding certain tax matters is filed electronically herewith.

(13) (a) Transfer, Dividend Disbursing and Shareholders’ Servicing Agent Agreement between Columbia Acorn Trust and Columbia Management Investment Services Corp. dated May 1, 2010, Schedule A last amended June 8, 2011. (10)

(13) (b) Side Letter Agreement to the Transfer, Dividend Disbursing and Shareholder’s Servicing Agent Agreement between Columbia Acorn Trust and Columbia Management Investment Services Corp. dated May 1, 2010 (9).

(13) (c) Compliance Agreement between Columbia Acorn Trust and Ameriprise Financial, Inc. dated May 1, 2010. (7)

(13) (d) Fee Waiver Agreement between Columbia Acorn Trust and Columbia Management Investment Services Corp. (relating to Columbia Acorn International) dated August 12, 2011 is filed electronically herewith.

(13) (e) Participation Agreement among Merrill Lynch Life Insurance Company, Columbia Acorn Trust and Columbia Funds Distributor, Inc. (now named Columbia Management Distributors, Inc.) dated March 4, 2005. (5)

(13) (f) Amendment No. 1 to Participation Agreement among Merrill Lynch Life Insurance Company, Columbia Acorn Trust and Columbia Management Distributors, Inc. (formerly Columbia Funds Distributor, Inc.) dated March 30, 2007. (6)

(13) (g) Participation Agreement among ML Life Insurance Company of New York, Columbia Acorn Trust and Columbia Funds Distributor, Inc. (now named Columbia Management Distributors, Inc.) dated March 4, 2005. (5)

(13) (h) Amendment No. 1 to Participation Agreement among ML Life Insurance Company of New York, Columbia Acorn Trust and Columbia Management Distributors, Inc. (formerly Columbia Funds Distributor, Inc.) dated March 30, 2007. (6)

(14) (a) Consent of Independent Registered Public Accounting Firm (Ernst & Young LLP). (8)

(14) (b) Consent of Independent Registered Public Accounting Firm (PricewaterhouseCoopers LLP). (8)

(15) Not applicable.

(16) Not applicable.

(17) (a) Code of Ethics for Columbia Wanger Asset Management, LLC, Columbia Acorn Trust and Wanger Advisors Trust effective February 27, 2011. (9)

(17) (b) Code of Ethics for Non-Management Trustees as amended September 22, 2010. (7)

(17) (c) Code of Ethics for Columbia Management Investment Distributors, Inc., the principal underwriter of the Funds, effective May 1, 2010. (9)

1. Incorporated by reference to post-effective amendment No. 53 to the Registrant’s registration statement on form N-1A, Securities Act registration number 2-34223 (the “Registration Statement”), filed on April 30, 1996.

2. Incorporated by reference to Registrant’s post-effective amendment No. 61 to the Registration Statement filed on April 30, 1998.

3. Incorporated by reference to Registrant’s post-effective amendment No. 70 to the Registration Statement filed on May 1, 2001.

4. Incorporated by reference to Registrant’s post-effective amendment No. 77 to the Registration Statement filed on March 1, 2005.

5. Incorporated by reference to Registrant’s post-effective amendment No. 79 to the Registration Statement filed on April 28, 2006.

6. Incorporated by reference to Registrant’s post-effective amendment No. 80 to the Registration Statement filed on April 30, 2007.

7. Incorporated by reference to Registrant’s post-effective amendment No. 87 to the Registration Statement filed on September 27, 2010.

8. Incorporated by reference to Registrant’s registration statement on Form N-14, Securities Act registration number 333-170630, filed on November 16, 2010.

9. Incorporated by reference to Registrant’s post-effective amendment No. 88 to the Registration Statement filed on April 29, 2011.

10. Incorporated by reference to Registrant’s post-effective amendment No. 91 to the Registration Statement filed

on August 17, 2011.

Item 17. Undertakings

(1) The undersigned Registrant agrees that prior to any public reoffering of the securities registered through the use of a prospectus which is a part of this registration statement on Form N-14 by any person or party who is deemed to be an underwriter within the meaning of Rule 145(c) of the Securities Act, the reoffering prospectus will contain the information called for by the applicable registration form for reofferings by persons who may be deemed underwriters, in addition to the information called for by the other items of the applicable form.

(2) The undersigned Registrant agrees that every prospectus that is filed under paragraph (1) above will be filed as a part of an amendment to the registration statement and will not be used until the amendment is effective, and that, in determining any liability under the Securities Act, each post-effective amendment shall be deemed to be a new registration statement for the securities offered therein, and the offering of the securities at that time shall be deemed to be the initial bona fide offering of them.

(3) The Registrant hereby files the opinion of counsel supporting the tax consequences of the proposed reorganization required by Item 16(12) through this amendment to the registration statement on Form N-14, the closing of the transaction having occurred on August 15, 2011.

SIGNATURES

As required by the Securities Act of 1933, the Registrant, Columbia Acorn Trust, certifies that it meets all the requirements for effectiveness of this Registration Statement under Rule 485(b) under the Securities Act of 1933 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Chicago, and the State of Illinois on the 7th day of October 2011.

COLUMBIA ACORN TRUST
By:	/s/    CHARLES P. MCQUAID
Name:	Charles P. McQuaid
Title:	President

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the date indicated:

SIGNATURES	TITLE	DATE
/S/    LAURA M. BORN         Laura M. Born	Trustee and Chair	October 7, 2011
/S/    MICHELLE L. COLLINS         Michelle L. Collins	Trustee	October 7, 2011
/S/    MAUREEN M. CULHANE         Maureen M. Culhane	Trustee	October 7, 2011
/S/    MARGARET M. EISEN         Margaret M. Eisen	Trustee	October 7, 2011
/S/    JOHN C. HEATON         John C. Heaton	Trustee	October 7, 2011
/S/    STEVEN N. KAPLAN         Steven N. Kaplan	Trustee	October 7, 2011
/S/    ALLAN B. MUCHIN         Allan B. Muchin	Trustee	October 7, 2011
/S/    DAVID J. RUDIS         David J. Rudis	Trustee	October 7, 2011
/S/    DAVID B. SMALL         David B. Small	Trustee	October 7, 2011
/S/    CHARLES P. MCQUAID         Charles P. McQuaid	Trustee and President (principal executive officer)	October 7, 2011
/S/    BRUCE H. LAUER         Bruce H. Lauer	Treasurer (principal financial and accounting officer)	October 7, 2011

Exhibit Index

Exhibit No.	Description
(4)	Agreement and Plan of Reorganization
(12)	Opinion of counsel regarding certain tax matters
(13)(d)	Fee Waiver Agreement between Columbia Acorn Trust and Columbia Management Investment Services Corp. (relating to Columbia Acorn International) dated August 12, 2011.

EX-99.(4)

EXECUTION COPY

Agreement and Plan of Reorganization

THIS AGREEMENT AND PLAN OF REORGANIZATION dated as of December 20, 2010, is by and among RiverSource International Managers Series, Inc., a Minnesota corporation (the “Acquired Company”), on behalf RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund, each a series thereof (each an “Acquired Fund”), Columbia Acorn Trust, a Massachusetts business trust (the “Acquiring Company”), on behalf of Acorn International (the “Acquiring Fund”), and, for purposes of Sections 4.3, 4.4, 6.3 and 9.2 of this Agreement, Columbia Management Investment Advisers, LLC (“Columbia”).

This Agreement shall be treated as if each reorganization between an Acquired Fund and the Acquiring Fund contemplated hereby had been the subject of a separate agreement.

This Agreement is intended to be and is adopted as a plan of reorganization and liquidation within the meaning of Section 361(a) and Section 368(a) of the United States Internal Revenue Code of 1986, as amended (the “Code”), and any successor provision. The reorganization will consist of the transfer of all of the assets of each Acquired Fund attributable to each class of its shares in exchange for shares of each class of shares of the Acquiring Fund (the “Acquisition Shares”), and the assumption by the Acquiring Fund of the liabilities of each Acquired Fund and the distribution of the Acquisition Shares to the relevant shareholders of such Acquired Fund in liquidation of such Acquired Fund, all upon the terms and conditions set forth in this Agreement.

In consideration of the premises and of the covenants and agreements hereinafter set forth, the parties hereto covenant and agree as follows:

1. TRANSFER OF ASSETS OF EACH ACQUIRED FUND IN EXCHANGE FOR ASSUMPTION OF LIABILITIES AND ACQUISITION SHARES AND LIQUIDATION OF SUCH ACQUIRED FUND.

1.1. Subject to the terms and conditions herein set forth and on the basis of the representations and warranties contained herein,

(a) Each Acquired Fund will transfer and deliver to the Acquiring Fund, and the Acquiring Fund will acquire all the assets of each Acquired Fund, as set forth in paragraph 1.2;

(b) The Acquiring Fund will assume all of each Acquired Fund’s liabilities and obligations of any kind whatsoever, whether absolute, accrued, contingent or otherwise, in existence on the Closing Date (as defined in paragraph 1.2 hereof) (the “Obligations”), except that expenses of the reorganization contemplated hereby to be paid by the Acquired Fund pursuant to paragraph 9.2 shall not be assumed or paid by the Acquiring Fund; and

(c) The Acquiring Fund will issue and deliver to each Acquired Fund in exchange for the net assets attributable to each class of its shares a number of Acquisition Shares of such class (including fractional shares, if any) determined by dividing the value of such net assets, computed in the manner and as of the time and date set forth in paragraph 2.1, by the net asset value of one Acquisition Share of such class computed in the manner and as of the time and date set forth in paragraph 2.2. Such transactions shall take place at the closing provided for in paragraph 3.1 (the “Closing”).

1.2. The assets of each Acquired Fund to be acquired by the Acquiring Fund shall consist of all cash, securities, dividends and interest receivable, receivables for shares sold and all other assets that are owned by the Acquired Fund on the closing date provided in paragraph 3.1 (the “Closing Date”) and any deferred expenses, other than unamortized reorganizational expenses, shown as an asset on the books of the Acquired Fund on the Closing Date. The Acquiring Fund agrees that all rights to indemnification and all limitations of liability existing in favor of each Acquired Fund’s current and former directors and officers, acting in their capacities as such, under each Acquired Fund’s organizational documents as in effect as of the date of this Agreement or under any other agreement of the Acquired Fund shall survive the reorganization as obligations of the Acquiring Fund, and shall continue in full force and effect, without any amendment thereto, and shall constitute rights which may be asserted against the Acquiring Fund, its successors or assigns.

1.3. As provided in paragraph 3.4, on the Closing Date or as soon thereafter as is conveniently practicable (the “Liquidation Date”), each Acquired Fund will liquidate and distribute pro rata to its shareholders of record of each class of its shares, determined as of the close of business on the Valuation Date (as defined in paragraph 2.1), the Acquisition Shares of the corresponding class received by the Acquired Fund pursuant to paragraph 1.1. Such liquidation and distribution will be accomplished by the transfer of the Acquisition Shares then credited to the account of each Acquired Fund on the books of the Acquiring Fund to open accounts on the share records of the Acquiring Fund in the names of the Acquired Fund’s shareholders and representing the respective pro rata number of Acquisition Shares due such shareholders. The Acquiring Fund shall not be obligated to issue certificates representing Acquisition Shares in connection with such exchange.

1.4. With respect to Acquisition Shares distributable pursuant to paragraph 1.3 to an Acquired Fund shareholder holding a certificate or certificates for shares of the Acquired Fund, if any, on the Valuation Date, the Acquired Fund will not permit such shareholder to receive Acquisition Share certificates therefor, exchange such Acquisition Shares for shares of other investment companies, effect an account transfer of such Acquisition Shares or pledge or redeem such Acquisition Shares until such Acquired Fund shareholder has surrendered all his or her outstanding certificates for Acquired Fund shares or, in the event of lost certificates, posted adequate bond.

1.5. As soon as practicable after the Closing Date, each Acquired Fund shall make all filings and take all other steps as shall be necessary and proper to effect its complete dissolution under applicable state law. After the Closing Date, neither Acquired Fund shall conduct any business except in connection with its dissolution.

2. VALUATION.

2.1. For the purpose of paragraph 1, the value of each Acquired Fund’s assets to be acquired by the Acquiring Fund hereunder shall be the value of such assets computed as of the close of regular trading on the New York Stock Exchange on the business day next preceding the Closing (such time and date being herein called the “Valuation Date”) using the valuation procedures set forth in the organizational documents of the Acquiring Fund and the then current prospectus or prospectuses or statement or statements of additional information of the Acquiring Fund (collectively, as amended or supplemented from time to time, the “Acquiring Fund Prospectus”), after deduction for the expenses of the reorganization contemplated hereby to be paid by the Acquired Fund pursuant to paragraph 9.2, and shall be certified by the Acquired Fund.

2.2. For the purpose of paragraph 2.1, the net asset value of an Acquisition Share of each class shall be the net asset value per share computed as of the close of regular trading on the New York Stock Exchange on the Valuation Date, using the valuation procedures set forth in the organizational documents of the Acquiring Fund and the Acquiring Fund Prospectus.

3. CLOSING AND CLOSING DATE.

3.1. The Closing Date shall be on August 15, 2011, or on such other date as the Acquiring Fund and Acquired Fund may agree. The Closing shall be held at Columbia’s offices, One Financial Center, Boston, Massachusetts 02111 (or such other place as the parties may agree), at such time as the parties may agree.

3.2. The portfolio securities of each Acquired Fund shall be made available by the Acquired Fund to the custodian for the Acquiring Fund (the “Custodian”), for examination no later than five business days preceding the Valuation Date. On the Closing Date, such portfolio securities and all the Acquired Fund’s cash shall be delivered by the Acquired Fund to the Custodian for the account of the Acquiring Fund, such portfolio securities to be duly endorsed in proper form for transfer in such manner and condition as to constitute good delivery thereof in accordance with the custom of brokers or, in the case of portfolio securities held in the U.S. Treasury Department’s book-entry system or by the Depository Trust Company, Participants Trust Company or other third party depositories, by transfer to the account of the Custodian in accordance with Rule 17f-4, Rule 17f-5 or Rule 17f-7, as the case may be, under the Investment Company Act of 1940, as amended (the “1940 Act”) and accompanied by all necessary federal and state stock transfer stamps or a check for the appropriate purchase price thereof. The cash delivered shall be in the form of currency or certified or official bank checks, payable to the order of “Custodian, as custodian for Acorn International.”

2

3.3. In the event that on the Valuation Date (a) the New York Stock Exchange shall be closed to trading or trading thereon shall be restricted, or (b) trading or the reporting of trading on the New York Stock Exchange or elsewhere shall be disrupted so that accurate appraisal of the value of the net assets of each Acquired Fund or the Acquiring Fund is impracticable, the Closing Date shall be postponed until the first business day after the day when trading shall have been fully resumed and reporting shall have been restored; provided that if trading shall not be fully resumed and reporting restored within three business days of the Valuation Date, this Agreement may be terminated by either the Acquired Fund or the Acquiring Fund upon the giving of written notice to the other party.

3.4. At the Closing, each Acquired Fund or its transfer agent shall deliver to the Acquiring Fund or its designated agent a list of the names and addresses of the Acquired Fund’s shareholders and the number of outstanding shares of each class of the Acquired Fund owned by each Acquired Fund shareholder, all as of the close of business on the Valuation Date, certified by any Vice President, Secretary or Assistant Secretary of the Acquired Fund. The Acquiring Fund will provide to the Acquired Fund evidence satisfactory to the Acquired Fund that the Acquisition Shares issuable pursuant to paragraph 1.1 have been credited to the Acquired Fund’s account on the books of the Acquiring Fund. On the Liquidation Date, the Acquiring Fund will provide to each Acquired Fund evidence satisfactory to each Acquired Fund that such Acquisition Shares have been credited pro rata to open accounts in the names of each Acquired Fund’s shareholders as provided in paragraph 1.3.

3.5. At the Closing, each party shall deliver to the other such bills of sale, instruments of assumption of liabilities, checks, assignments, stock certificates, receipts or other documents as such other party or its counsel may reasonably request in connection with the transfer of assets, assumption of liabilities and dissolution contemplated by paragraph 1.

4. REPRESENTATIONS AND WARRANTIES.

4.1. Each Acquired Fund represents and warrants the following to the Acquiring Fund as of the date hereof and agrees to confirm the continuing accuracy and completeness in all material respects of the following on the Closing Date:

(a) The Acquired Company is duly organized, validly existing and in good standing under the laws of Minnesota;

(b) The Acquired Company is a duly registered investment company classified as a management company of the open-end type and its registration with the Securities and Exchange Commission as an investment company under the 1940 Act is in full force and effect, and the Acquired Fund is a separate series thereof duly designated in accordance with the applicable provisions of the organizational documents of the Acquired Company and the 1940 Act;

(c) The Acquired Fund is not in violation in any material respect of any provision of its organizational documents or of any agreement, indenture, instrument, contract, lease or other undertaking to which the Acquired Fund is a party or by which the Acquired Fund is bound, and the execution, delivery and performance of this Agreement will not result in any such violation;

(d) The Acquired Fund has no material contracts or other commitments (other than this Agreement and such other contracts as may be entered into in the ordinary course of its business) that if terminated may result in material liability to the Acquired Fund or under which (whether or not terminated) any material payments for periods subsequent to the Closing Date will be due from the Acquired Fund;

(e) To the knowledge of the Acquired Fund, except as has been disclosed in writing to the Acquiring Fund, no litigation or administrative proceeding or investigation of or before any court or governmental body is currently pending or threatened as to the Acquired Fund, any of its properties or assets, or any person whom the Acquired Fund may be obligated to indemnify in connection with such litigation, proceeding or investigation, and the Acquired Fund is not a party to or subject to the provisions of any order, decree or judgment of any court or governmental body that materially and adversely affects its business or its ability to consummate the transactions contemplated hereby;

3

(f) The statement of assets and liabilities, the statement of operations, the statement of changes in net assets, and the schedule of investments of the Acquired Fund, as of the last day of and for its most recently completed fiscal year, audited by the Acquired Fund’s independent registered public accounting firm (and, if applicable, an unaudited statement of assets and liabilities, statement of operations, statement of changes in net assets and schedule of investments for any subsequent semiannual period following the most recently completed fiscal year), copies of which have been furnished to the Acquiring Fund, fairly reflect the financial condition and results of operations of the Acquired Fund as of such dates and for the periods then ended in accordance with generally accepted accounting principles consistently applied, and the Acquired Fund has no known liabilities of a material amount, contingent or otherwise, other than those shown on the statements of assets and liabilities referred to above or those incurred in the ordinary course of its business since the last day of the Acquired Fund’s most recently completed fiscal year;

(g) Since the last day of the Acquired Fund’s most recently completed fiscal year, there has not been any material adverse change in the Acquired Fund’s financial condition, assets, liabilities or business (other than changes occurring in the ordinary course of business), or any incurrence by the Acquired Fund of indebtedness, except as has been disclosed in writing to the Acquiring Fund. For the purposes of this subparagraph (g), distributions of net investment income and net realized capital gains, changes in portfolio securities, changes in the market value of portfolio securities or net redemptions shall be deemed to be in the ordinary course of business;

(h) As of the Closing Date, all federal and other tax returns and reports of the Acquired Fund required by law to have been filed by such date (giving effect to extensions) shall have been filed, and all federal and other taxes shown to be due on such returns and reports or on any assessment received shall have been paid, or provisions shall have been made for the payment thereof. All of the Acquired Fund’s tax liabilities will have been adequately provided for on its books. To the best of the Acquired Fund’s knowledge, it will not have had any tax deficiency or liability asserted against it or question with respect thereto raised, and it will not be under audit by the Internal Revenue Service or by any state or local tax authority for taxes in excess of those already paid;

(i) The Acquired Fund has met the requirements of subchapter M of the Code for treatment as a “regulated investment company” within the meaning of Section 851 of the Code in respect of each taxable year since commencement of operations, and will continue meeting such requirements at all times through the Closing Date. The Acquired Fund has not at any time since its inception been liable for, and is not now liable for, any material income tax or any excise tax pursuant to Section 4982 of the Code. The Acquired Fund is in compliance in all material respects with applicable regulations of the Internal Revenue Service pertaining to the reporting of dividends and other distributions on and redemptions of its capital stock and to withholding in respect of dividends and other distributions to shareholders, and is not liable for any material penalties that could be imposed thereunder;

(j) Exhibit B hereto sets forth the authorized capital of the Acquired Fund. All issued and outstanding shares of the Acquired Fund are, and at the Closing Date will be, duly and validly issued and outstanding, fully paid and non-assessable (except as set forth in the most recent prospectus or prospectuses or statement or statements of additional information constituting part of the Acquired Fund’s registration statement under the 1940 Act (collectively, as amended or supplemented from time to time, the “Acquired Fund Prospectus”)) by the Acquired Fund and will have been issued in compliance with all applicable registration or qualification requirements of federal and state securities laws. Except as set forth on Exhibit B hereto, no options, warrants or other rights to subscribe for or purchase, or securities convertible into, any shares of common stock of the Acquired Fund are outstanding and none will be outstanding on the Closing Date;

(k) The Acquired Fund’s investment operations from inception to the date hereof have been in compliance in all material respects with the investment policies and investment restrictions set forth in the Acquired Fund Prospectus, except as has been disclosed in writing to the Acquiring Fund;

(l) The execution, delivery and performance of this Agreement has been duly authorized by the directors of the Acquired Fund, and, upon approval thereof by the required majority of the shareholders of the Acquired

4

Fund, this Agreement will constitute the valid and binding obligation of the Acquired Fund enforceable in accordance with its terms except as the same may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting the enforcement of creditors’ rights generally and other equitable principles;

(m) The Acquisition Shares to be issued to the Acquired Fund pursuant to paragraph 1 will not be acquired for the purpose of making any distribution thereof other than to the Acquired Fund’s shareholders as provided in paragraph 1.3;

(n) The information provided by the Acquired Fund for use in the Registration Statement and Prospectus/Proxy Statement referred to in paragraph 5.3 shall be accurate and complete in all material respects and shall comply with federal securities and other laws and regulations as applicable thereto;

(o) No consent, approval, authorization or order of any court or governmental authority is required for the consummation by the Acquired Fund of the transactions contemplated by this Agreement, except such as may be required under the Securities Act of 1933, as amended (the “1933 Act”), the Securities Exchange Act of 1934, as amended (the “1934 Act”), the 1940 Act and state securities or “Blue Sky” laws (which terms used herein shall include the laws of the District of Columbia and of Puerto Rico);

(p) At the Closing Date, the Acquired Fund will have good and marketable title to its assets to be transferred to the Acquiring Fund pursuant to paragraph 1.1 and will have full right, power and authority to sell, assign, transfer and deliver the Investments (as defined below) and any other assets and liabilities of the Acquired Fund to be transferred to the Acquiring Fund pursuant to this Agreement. At the Closing Date, subject only to the delivery of the Investments and any such other assets and liabilities and payment therefor as contemplated by this Agreement, the Acquiring Fund will acquire good and marketable title thereto and will acquire the Investments and any such other assets and liabilities subject to no encumbrances, liens or security interests whatsoever and without any restrictions upon the transfer thereof, except as has been disclosed in writing to the Acquiring Fund. As used in this Agreement, the term “Investments” shall mean the Acquired Fund’s investments shown on the schedule of its investments as of the date of its most recently completed fiscal year, referred to in subparagraph 4.1(f) hereof, as supplemented with such changes in the portfolio as the Acquired Fund shall make, and changes resulting from stock dividends, stock split-ups, mergers and similar corporate actions through the Closing Date;

(q) At the Closing Date, the Acquired Fund will have sold such of its assets, if any, as are necessary based on information provided by the Acquiring Fund and contingent on the accuracy of such information to assure that, after giving effect to the acquisition of the assets of the Acquired Fund pursuant to this Agreement, the Acquiring Fund will remain a “diversified company” within the meaning of Section 5(b)(1) of the 1940 Act and in compliance with such other mandatory investment restrictions as are set forth in the Acquiring Fund Prospectus, as amended through the Closing Date; and

(r) No registration of any of the Investments would be required if they were, as of the time of such transfer, the subject of a public distribution by either the Acquiring Fund or the Acquired Fund, except as has been disclosed in writing by the Acquired Fund to the Acquiring Fund.

4.2. The Acquiring Fund represents and warrants the following to each Acquired Fund as of the date hereof and agrees to confirm the continuing accuracy and completeness in all material respects of the following on the Closing Date:

(a) The Acquiring Company is duly organized, validly existing and in good standing under the laws of Massachusetts;

(b) The Acquiring Company is a duly registered investment company classified as a management company of the open-end type and its registration with the Securities and Exchange Commission as an investment company under the 1940 Act is in full force and effect, and the Acquiring Fund, as applicable, is a separate series thereof duly designated in accordance with the applicable provisions of the organizational documents of the Acquiring Company and the 1940 Act;

5

(c) The Acquiring Fund Prospectus conforms in all material respects to the applicable requirements of the 1933 Act and the rules and regulations of the Securities and Exchange Commission thereunder and does not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, and there are no material contracts to which the Acquiring Fund is a party that are not referred to in the Acquiring Fund Prospectus or in the registration statement of which it is a part;

(d) At the Closing Date, the Acquiring Fund will have good and marketable title to its assets;

(e) The Acquiring Fund is not in violation in any material respect of any provisions of its organizational documents or of any agreement, indenture, instrument, contract, lease or other undertaking to which the Acquiring Fund is a party or by which the Acquiring Fund is bound, and the execution, delivery and performance of this Agreement will not result in any such violation;

(f) To the knowledge of the Acquiring Fund, except as has been disclosed in writing to the Acquired Fund, no litigation or administrative proceeding or investigation of or before any court or governmental body is currently pending or threatened as to the Acquiring Fund, any of its properties or assets, or any person whom the Acquiring Fund may be obligated to indemnify in connection with such litigation, proceeding or investigation, and the Acquiring Fund is not a party to or subject to the provisions of any order, decree or judgment of any court or governmental body that materially and adversely affects its business or its ability to consummate the transactions contemplated hereby;

(g) The statement of assets and liabilities, the statement of operations, the statement of changes in net assets, and the schedule of investments of the Acquiring Fund, as of the last day of and for its most recently completed fiscal year, audited by the Acquiring Fund’s independent registered public accounting firm (and, if applicable, an unaudited statement of assets and liabilities, statement of operations, statement of changes in net assets and schedule of investments for any subsequent semiannual period following the most recently completed fiscal year), copies of which have been furnished to the Acquired Fund, fairly reflect the financial condition and results of operations of the Acquiring Fund as of such dates and for the periods then ended in accordance with generally accepted accounting principles consistently applied, and the Acquiring Fund has no liabilities of a material amount, contingent or otherwise, other than those shown on the statements of assets and liabilities referred to above or those incurred in the ordinary course of its business since the last day of the Acquiring Fund’s most recently completed fiscal year;

(h) Since the last day of the Acquiring Fund’s most recently completed fiscal year, there has not been any material adverse change in the Acquiring Fund’s financial condition, assets, liabilities or business (other than changes occurring in the ordinary course of business), or any incurrence by the Acquiring Fund of indebtedness, except as has been disclosed in writing to the Acquired Fund. For the purposes of this subparagraph (h), distributions of net investment income and net realized capital gains, changes in portfolio securities, changes in the market value of portfolio securities or net redemptions shall be deemed to be in the ordinary course of business;

(i) As of the Closing Date, all federal and other tax returns and reports of the Acquiring Fund required by law to have been filed by such date (giving effect to extensions) shall have been filed, and all federal and other taxes shown to be due on such returns and reports or any assessments received shall have been paid, or provisions shall have been made for the payment thereof. All of the Acquiring Fund’s tax liabilities will have been adequately provided for on its books. To the best of the Acquiring Fund’s knowledge, it will not have had any tax deficiency or liability asserted against it or question with respect thereto raised, and it will not be under audit by the Internal Revenue Service or by any state or local tax authority for taxes in excess of those already paid;

(j) The Acquiring Fund has met the requirements of subchapter M of the Code for treatment as a “regulated investment company” within the meaning of Section 851 of the Code in respect of each taxable year since commencement of operations, and will continue to meet such requirements at all times through the Closing Date. The Acquiring Fund has not at any time since its inception been liable for, nor is it now liable for, any material income tax or any excise tax pursuant to Section 4982 of the Code. The Acquiring Fund is in

6

compliance in all material respects with applicable regulations of the Internal Revenue Service pertaining to the reporting of dividends and other distributions on and redemptions of its capital stock and to withholding in respect of dividends and other distributions to shareholders, and is not liable for any material penalties that could be imposed thereunder;

(k) Exhibit C hereto sets forth the authorized capital of the Acquiring Fund. All issued and outstanding shares of the Acquiring Fund are, and at the Closing Date will be, duly and validly issued and outstanding, fully paid and non-assessable (except as set forth in the Acquiring Fund Prospectus) by the Acquiring Fund and will have been issued in compliance with all applicable registration or qualification requirements of federal and state securities laws. Except as set forth on Exhibit C hereto, no options, warrants or other rights to subscribe for or purchase, or securities convertible into, any shares of the Acquiring Fund are outstanding and none will be outstanding on the Closing Date;

(l) The Acquiring Fund’s investment operations from inception to the date hereof have been in compliance in all material respects with the investment policies and investment restrictions set forth in the Acquiring Fund Prospectus;

(m) The execution, delivery and performance of this Agreement have been duly authorized by all necessary action on the part of the Acquiring Fund, and this Agreement constitutes the valid and binding obligation of the Acquiring Fund enforceable in accordance with its terms, except as the same may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting the enforcement of creditors’ rights generally and other equitable principles;

(n) The Acquisition Shares to be issued and delivered to each Acquired Fund pursuant to the terms of this Agreement will at the Closing Date have been duly authorized and, when so issued and delivered, will be duly and validly issued shares of the Acquiring Fund, and will be fully paid and non-assessable (except as set forth in the Acquiring Fund Prospectus) by the Acquiring Fund, and no shareholder of the Acquiring Fund will have any preemptive right of subscription or purchase in respect thereof;

(o) The information to be furnished by the Acquiring Fund for use in the Registration Statement and Prospectus/Proxy Statement referred to in paragraph 5.3 shall be accurate and complete in all material respects and shall comply with federal securities and other laws and regulations applicable thereto; and

(p) No consent, approval, authorization or order of any court or governmental authority is required for the consummation by the Acquiring Fund of the transactions contemplated by this Agreement, except such as may be required under the 1933 Act, the 1934 Act, the 1940 Act and state securities or “Blue Sky” laws (which term as used herein shall include the laws of the District of Columbia and of Puerto Rico).

4.3 Columbia represents and warrants to each of the Acquired Company, each Acquired Fund, the Acquiring Company and the Acquiring Fund as of the date hereof and as of the Closing Date that all of the information provided by Columbia, or its agents or affiliates, to the Boards of Trustees of the Acquiring Company and the Acquired Company (each, a “Board”) in connection with each Board’s consideration of the transactions contemplated hereby is accurate and complete in all material respects and contains no untrue statement of a material fact or omits to state a material fact necessary in order to make the statements made, in the light of the circumstances under which they were made, not misleading. Columbia agrees to confirm in writing in form reasonably acceptable to the Acquiring Fund and the Acquired Funds the continuing accuracy and completeness in all material respects of the foregoing representation and warranty on and as of the Closing Date.

4.4 Columbia agrees to assume liability for the breach of its representations and warranties set forth in subsection 4.3 to the extent of any actual loss (including reasonable legal fees and reasonable costs of investigation) incurred by any of the Acquiring Company, the Acquiring Fund, the Acquired Company or either Acquired Fund or their respective officers, trustees and employees as a result of said breach.

7

5. COVENANTS OF EACH ACQUIRED FUND AND THE ACQUIRING FUND.

Each Acquired Fund and the Acquiring Fund hereby covenants and agrees with the other as follows:

5.1. The Acquiring Fund and each Acquired Fund will each operate its business in the ordinary course between the date hereof and the Closing Date, it being understood that such ordinary course of business may include regular and customary periodic dividends and distributions.

5.2. Each Acquired Fund will call a meeting of its shareholders to be held prior to the Closing Date to consider and act upon this Agreement and take all other reasonable action necessary to obtain the required shareholder approval of the transactions contemplated hereby.

5.3. In connection with each Acquired Fund shareholders’ meeting referred to in paragraph 5.2, the Acquiring Fund will prepare a Prospectus/Proxy Statement for such meeting, to be included in a Registration Statement on Form N-14 (the “Registration Statement”), which the Acquiring Fund will prepare and file for registration under the 1933 Act of the Acquisition Shares to be distributed to each Acquired Fund’s shareholders pursuant hereto, all in compliance with the applicable requirements of the 1933 Act, the 1934 Act, and the 1940 Act.

5.4. The information to be furnished by each Acquired Fund for use in the Registration Statement and the information to be furnished by the Acquiring Fund for use in the Prospectus/Proxy Statement, each as referred to in paragraph 5.3, shall be accurate and complete in all material respects and shall comply with federal securities and other laws and regulations thereunder applicable thereto.

5.5. The Acquiring Fund will advise each Acquired Fund promptly if at any time prior to the Closing Date the assets of such Acquired Fund include any securities that the Acquiring Fund is not permitted to acquire.

5.6. Subject to the provisions of this Agreement, each Acquired Fund and the Acquiring Fund will each take, or cause to be taken, all action, and do or cause to be done, all things reasonably necessary, proper or advisable to cause the conditions to the other party’s obligations to consummate the transactions contemplated hereby to be met or fulfilled and otherwise to consummate and make effective such transactions.

5.7. The Acquiring Fund will use all reasonable efforts to obtain the approvals and authorizations required by the 1933 Act, the 1940 Act and such of the state securities or “Blue Sky” laws as it may deem appropriate in order to continue its operations after the Closing Date.

5.8 In the event that at any time after the Closing, any Acquired Fund is entitled to receive any monies or other assets (e.g. upon settlement of a class action proceeding), the Acquiring Fund shall be entitled to receive such monies or other assets.

5.9 Neither the Acquired Funds nor the Acquiring Fund will knowingly take any action or fail to take any action that would cause the transactions contemplated under this Agreement not to qualify as reorganizations under Section 368(a) of the Code.

6. CONDITIONS PRECEDENT TO OBLIGATIONS OF EACH ACQUIRED FUND.

The obligation of each Acquired Fund to consummate the transactions provided for herein shall be subject, at its election, to the performance by the Acquiring Fund of all the obligations to be performed by it hereunder on or before the Closing Date and, in addition thereto, to the following further conditions:

6.1. The Acquiring Fund shall have delivered to each Acquired Fund a certificate executed in its name by its President or a Vice President and its Treasurer or an Assistant Treasurer, in form and substance satisfactory to the Acquired Fund and dated as of the Closing Date, to the effect that the representations and warranties of the Acquiring Fund made in this Agreement are true and correct at and as of the Closing Date, except as they may be affected by the transactions contemplated by this Agreement, and that the Acquiring Fund has complied with all the covenants and agreements

8

and satisfied all of the conditions on its part to be performed or satisfied under this Agreement at or prior to the Closing Date.

6.2. The Acquired Fund shall have received a favorable opinion of Perkins Coie LLP, dated the Closing Date and in a form satisfactory to the Acquired Fund, to the following effect:

(a) The Acquiring Company is duly organized and validly existing under the laws of Massachusetts and has power to own all of its properties and assets and to carry on its business as currently conducted, and the Acquiring Fund is a separate series thereof duly constituted in accordance with the applicable provisions of the 1940 Act and the organizational documents of the Acquiring Company;

(b) This Agreement has been duly authorized, executed and delivered on behalf of the Acquiring Fund and, assuming the Registration Statement and Prospectus/Proxy Statement referred to in paragraph 5.3 comply with applicable federal securities laws and assuming the due authorization, execution and delivery of this Agreement by the Acquired Fund, is the valid and binding obligation of the Acquiring Fund enforceable against the Acquiring Fund in accordance with its terms, except as the same may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting the enforcement of creditors’ rights generally and other equitable principles;

(c) The Acquiring Fund has the power to assume the liabilities to be assumed by it hereunder and upon consummation of the transactions contemplated hereby the Acquiring Fund will have duly assumed such liabilities;

(d) The Acquisition Shares to be issued for transfer to the Acquired Fund’s shareholders as provided by this Agreement are duly authorized and upon such transfer and delivery will be validly issued and outstanding and fully paid and nonassessable shares of the Acquiring Fund, and no shareholder of the Acquiring Fund has any preemptive right of subscription or purchase in respect thereof;

(e) The execution and delivery of this Agreement did not, and the performance by the Acquiring Fund of its obligations hereunder will not, violate the Acquiring Fund’s organizational documents, or any provision of any agreement known to such counsel to which the Acquiring Fund is a party or by which it is bound or, to the knowledge of such counsel, result in the acceleration of any obligation or the imposition of any penalty under any agreement, judgment or decree to which the Acquiring Fund is a party or by which it is bound;

(f) To the knowledge of such counsel, no consent, approval, authorization or order of any court or governmental authority is required for the consummation by the Acquiring Fund of the transactions contemplated by this Agreement except such as may be required under state securities or “Blue Sky” laws or such as have been obtained;

(g) Such counsel does not know of any legal or governmental proceedings relating to the Acquiring Fund existing on or before the date of mailing of the Prospectus/Proxy Statement referred to in paragraph 5.3 or the Closing Date required to be described in the Registration Statement that are not described as required;

(h) The Acquiring Company is registered with the Securities and Exchange Commission as an investment company under the 1940 Act; and

(i) To the knowledge of such counsel, except as has been disclosed in writing to the Acquired Fund, no litigation or administrative proceeding or investigation of or before any court or governmental body is currently pending or threatened as to the Acquiring Fund or any of its properties or assets or any person whom the Acquired Fund may be obligated to indemnify in connection with such litigation, proceeding or investigation, and the Acquiring Fund is not a party to or subject to the provisions of any order, decree or judgment of any court or governmental body that materially and adversely affects its business or its ability to consummate the transaction contemplated hereby.

9

6.3. For the period beginning at the Closing Date and ending not less than six years thereafter, Columbia, its successors and assigns, shall provide, or cause to be provided, liability coverage at least comparable in scope and amount to the liability coverage currently applicable to any former and/or current directors and officers of the Acquired Funds as of the date of this Agreement, covering the actions of such directors and officers of the Acquired Funds for the period(s) they served as such and shall bear any related costs or expenses.

7. CONDITIONS PRECEDENT TO OBLIGATIONS OF THE ACQUIRING FUND.

The obligations of the Acquiring Fund to complete the transactions provided for herein shall be subject, at its election, to the performance by each Acquired Fund of all the obligations to be performed by it hereunder on or before the Closing Date and, in addition thereto, to the following further conditions:

7.1. Each Acquired Fund shall have delivered to the Acquiring Fund a certificate executed in its name by its President or a Vice President and its Treasurer or an Assistant Treasurer, in form and substance satisfactory to the Acquiring Fund and dated as of the Closing Date, to the effect that the representations and warranties of each Acquired Fund made in this Agreement are true and correct at and as of the Closing Date, except as they may be affected by the transactions contemplated by this Agreement, and that each Acquired Fund has complied with all the covenants and agreements and satisfied all of the conditions on its part to be performed or satisfied under this Agreement at or prior to the Closing Date;

7.2. The Acquiring Fund shall have received a favorable opinion of counsel to each Acquired Fund dated the Closing Date and in a form satisfactory to the Acquiring Fund, to the following effect:

(a) The Acquired Company is duly organized and validly existing under the laws of its state of organization and has power to own all of its properties and assets and to carry on its business as currently conducted, and each Acquired Fund is a separate series thereof duly constituted in accordance with the applicable provisions of the 1940 Act and the organizational documents of the Acquired Company;

(b) This Agreement has been duly authorized, executed and delivered on behalf of each Acquired Fund and, assuming the Registration Statement and Prospectus/Proxy Statement referred to in paragraph 5.3 comply with applicable federal securities laws and assuming the due authorization, execution and delivery of this Agreement by the Acquiring Fund, is the valid and binding obligation of each Acquired Fund enforceable against each Acquired Fund in accordance with its terms, except as the same may be limited by bankruptcy, insolvency, reorganization or other similar laws affecting the enforcement of creditors’ rights generally and other equitable principles;

(c) Each Acquired Fund has the power to sell, assign, transfer and deliver the assets to be transferred by it hereunder, and, upon consummation of the transactions contemplated hereby, each Acquired Fund will have duly transferred such assets to the Acquiring Fund;

(d) The execution and delivery of this Agreement did not, and the performance by each Acquired Fund of its obligations hereunder will not, violate each Acquired Fund’s organizational documents or any provision of any agreement known to such counsel to which each Acquired Fund is a party or by which it is bound or, to the knowledge of such counsel, result in the acceleration of any obligation or the imposition of any penalty under any agreement, judgment or decree to which each Acquired Fund is a party or by which it is bound;

(e) To the knowledge of such counsel, no consent, approval, authorization or order of any court or governmental authority is required for the consummation by each Acquired Fund of the transactions contemplated by this Agreement, except such as have been obtained;

(f) Such counsel does not know of any legal or governmental proceedings relating to each Acquired Fund existing on or before the date of mailing of the Prospectus/Proxy Statement referred to in paragraph 5.3 or the Closing Date required to be described in the Prospectus/Proxy Statement that are not described as required;

10

(g) The Acquired Company is registered with the Securities and Exchange Commission as an investment company under the 1940 Act; and

(h) To the knowledge of such counsel, except as has been disclosed in writing to the Acquiring Fund, no litigation or administrative proceeding or investigation of or before any court or governmental body is currently pending or threatened as to each Acquired Fund or any of its properties or assets or any person whom the Acquiring Fund may be obligated to indemnify in connection with such litigation, proceeding or investigation, and each Acquired Fund is not a party to or subject to the provisions of any order, decree or judgment of any court or governmental body that materially and adversely affects its business or its ability to consummate the transaction contemplated thereby.

7.3. On or prior to the Closing Date, each Acquired Fund shall have declared and paid a dividend or dividends which, together with all previous dividends, shall have the effect of distributing (i) all of the excess of each Acquired Fund’s interest income excludable from gross income under Section 103 of the Code over each Acquired Fund’s deductions disallowed under Section 265 of the Code and (ii) all of each Acquired Fund’s investment company taxable income as defined in Section 852 of the Code (in each case computed without regard to any deduction for dividends paid) net capital gains realized (after reduction for any capital loss carryover).

7.4. Each Acquired Fund shall have furnished to the Acquiring Fund a certificate, signed by the President (or any Vice President) and the Treasurer (or Assistant Treasurer) of each Acquired Fund, as to the adjusted tax basis in the hands of each Acquired Fund of the securities delivered to the Acquiring Fund pursuant to this Agreement.

7.5. The custodian of each Acquired Fund shall have delivered to the Acquiring Fund a certificate identifying all of the assets of each Acquired Fund held by such custodian as of the Valuation Date.

8. FURTHER CONDITIONS PRECEDENT TO OBLIGATIONS OF EACH ACQUIRED FUND AND THE ACQUIRING FUND.

The respective obligations of each Acquired Fund and the Acquiring Fund hereunder are subject to the further conditions that on or before the Closing Date:

8.1. This Agreement and the transactions contemplated herein shall have received all necessary shareholder approvals at the meeting of shareholders of each Acquired Fund referred to in paragraph 5.2.

8.2. On the Closing Date, no action, suit or other proceeding shall be pending before any court or governmental agency in which it is sought to restrain or prohibit, or obtain damages or other relief in connection with, this Agreement or the transactions contemplated hereby.

8.3. All consents of other parties and all other consents, orders and permits of federal, state and local regulatory authorities (including those of the Securities and Exchange Commission and of state “Blue Sky” and securities authorities) deemed necessary by the Acquired Fund or the Acquiring Fund to permit consummation, in all material respects, of the transactions contemplated hereby shall have been obtained, except when failure to obtain any such consent, order or permit would not involve a risk of a material adverse effect on the assets or properties of the Acquired Fund or the Acquiring Fund.

8.4. The Registration Statement shall have become effective under the 1933 Act and no stop order suspending the effectiveness thereof shall have been issued and, to the best knowledge of the parties hereto, no investigation or proceeding for that purpose shall have been instituted or be pending, threatened or contemplated under the 1933 Act.

8.5. The Acquired Fund shall have received a favorable opinion of Drinker Biddle & Reath LLP satisfactory to the Acquiring Fund, and the Acquiring Fund shall have received a favorable opinion of Drinker Biddle & Reath LLP satisfactory to the Acquired Fund, substantially to the effect that, on the basis of existing provisions of the Code, Treasury regulations promulgated thereunder, current administrative rules and court decisions, for federal income tax purposes:

11

(a) The transactions contemplated by this Agreement will constitute a reorganization within the meaning of Section 368(a) of the Code, and the Acquired Fund and the Acquiring Fund will each be “a party to a reorganization” within the meaning of Section 368(b) of the Code;

(b) No gain or loss will be recognized by the Acquired Fund upon (i) the transfer of its assets to the Acquiring Fund in exchange for the Acquisition Shares and the assumption by the Acquiring Fund of the liabilities of the Acquired Fund or (ii) the distribution of the Acquisition Shares by the Acquired Fund to its shareholders in liquidation, as contemplated in paragraph 1 hereof;

(c) No gain or loss will be recognized by the Acquiring Fund upon receipt of the assets of the Acquired Fund in exchange for the assumption of the liabilities and obligations;

(d) The tax basis of the assets of the Acquired Fund transferred to the Acquiring Fund will be the same as the tax basis of such assets immediately prior to the transfer;

(e) The holding period of the assets of the Acquired Fund transferred to the Acquiring Fund will include the period during which such assets were held by the Acquired Fund;

(f) No gain or loss will be recognized by the Acquired Fund’s shareholders upon the exchange of all of their shares of the Acquired Fund for the Acquisition Shares;

(g) The aggregate tax basis of Acquisition Shares received by a shareholder of the Acquired Fund will be the same as the aggregate tax basis of the Acquired Fund’s shares exchanged therefor;

(h) An Acquired Fund shareholder’s holding period for the Acquisition Shares received will include the holding period for the Acquired Fund’s shares exchanged therefor, provided the shareholder held the Acquired Fund’s shares as a capital asset on the date of the exchange; and

(i) The Acquiring Fund will succeed to and take into account the items of the Acquired Fund described in Section 381(c) of the Code, subject to the conditions and limitations specified in Sections 381, 382, 383 and 384 of the Code and the regulations thereunder.

Each opinion will be based on certain factual certifications and representations made by officers of Columbia, the Acquired Fund, Acquiring Fund, the Acquired Company and the Acquiring Company and will also be based on customary assumptions, and is not a guarantee that the tax consequences of the transaction will be as described above. There is no assurance that the Internal Revenue Service or a court would agree with the opinions. Counsel will express no view with respect to the effect of the reorganization on any transferred asset as to which any unrealized gain or loss is required to be recognized at the end of a taxable year (or on the termination or transfer thereof) under federal income tax principles.

8.6. At any time prior to the Closing, any of the foregoing conditions of this Agreement may be waived jointly by the Board of Trustees/Directors of each of the Acquired Fund and the Acquiring Fund, if, in their judgment, such waiver will not have a material adverse effect on the interests of the shareholders of the Acquired Fund or the Acquiring Fund.

9. BROKERAGE FEES AND EXPENSES; INDEMNIFICATION.

9.1. Each Acquired Fund and the Acquiring Fund represents and warrants to the other that there are no brokers or finders entitled to receive any payments in connection with the transactions provided for herein.

9.2. All fees paid to governmental authorities for the registration or qualification of the Acquisition Shares and all transfer agency costs related to the Acquisition Shares shall be allocated to the Acquiring Fund. All fees and expenses related to printing and mailing communications to Acquired Fund shareholders shall be allocated to the respective Acquired Fund. All of the other expenses of the transactions, including without limitation, accounting, legal and custodial expenses contemplated by this Agreement shall be allocated equally among each Acquired Fund

12

and the Acquiring Fund. The expenses detailed above shall be borne by the Fund to which they are allocated; except that Columbia shall (i) bear such expenses to the extent such expenses exceed the anticipated reduction in expenses borne by the Acquiring Fund’s shareholders over the first year following the reorganization and (ii) bear any brokerage or legal fees allocated to the Acquiring Fund. In the event the Closing does not occur, Columbia shall bear all such expenses.

10. ENTIRE AGREEMENT; SURVIVAL OF WARRANTIES.

10.1. Each Acquired Fund and the Acquiring Fund agrees that neither party has made any representation, warranty or covenant not set forth herein and that this Agreement constitutes the entire agreement between the parties.

10.2. The representations, warranties and covenants contained in this Agreement or in any document delivered pursuant hereto or in connection herewith shall not survive the consummation of the transactions contemplated hereunder except paragraphs 1.1, 1.2, 1.3, 1.5, 4.3, 4.4, 5.4, 5.6, 5.8, 6.2, 6.3, 7.2, 9, 10, 13 and 14.

11. TERMINATION.

11.1. This Agreement may be terminated by the mutual agreement of each Acquired Fund and the Acquiring Fund. In addition, either an Acquired Fund or the Acquiring Fund may at its option terminate this Agreement at or prior to the Closing Date because:

(a) of a material breach by any other party of any representation, warranty, covenant or agreement contained herein to be performed by the other party at or prior to the Closing Date;

(b) a condition herein expressed to be precedent to the obligations of the terminating party has not been met and it reasonably appears that it will not or cannot be met; or

(c) any governmental authority of competent jurisdiction shall have issued any judgment, injunction, order, ruling or decree or taken any other action restraining, enjoining or otherwise prohibiting this Agreement or the consummation of any of the transactions contemplated herein and such judgment, injunction, order, ruling, decree or other action becomes final and non-appealable; provided that the party seeking to terminate this Agreement pursuant to this Section 11.1(c) shall have used its reasonable best efforts to have such judgment, injunction, order, ruling, decree or other action lifted, vacated or denied. If the transactions contemplated by this Agreement have not been substantially completed by [            ] this Agreement shall automatically terminate on that date unless a later date is agreed to by both the Acquired Fund and the Acquiring Fund.

11.2. If for any reason the transactions contemplated by this Agreement are not consummated, subject to the provisions of Section 9.2, no party shall be liable to any other party for any damages resulting therefrom, including without limitation, consequential damages.

12. AMENDMENTS.

This Agreement may be amended, modified or supplemented in such manner as may be mutually agreed upon in writing by the authorized officers of each Acquired Fund and the Acquiring Fund; provided, however, that following the shareholders’ meeting called by each Acquired Fund pursuant to paragraph 5.2 no such amendment may have the effect of changing the provisions for determining the number of the Acquisition Shares to be issued to shareholders of such Acquired Fund under this Agreement to the detriment of such shareholders without their further approval.

13. NOTICES.

Any notice, report, statement or demand required or permitted by any provisions of this Agreement shall be in writing and shall be given by telecopy or certified mail addressed to the Acquired Fund, One Financial Center, Boston, Massachusetts 02111, Attention: Secretary or the Acquiring Fund, 227 West Monroe Street, Suite 3000, Chicago, Illinois 60606, Attention Secretary.

13

14. HEADINGS; COUNTERPARTS; GOVERNING LAW; ASSIGNMENT; NON-RECOURSE.

14.1. The article and paragraph headings contained in this Agreement are for reference purposes only and shall not affect in any way the meaning or interpretation of this Agreement.

14.2. This Agreement may be executed in any number of counterparts, each of which shall be deemed an original.

14.3. This Agreement shall be governed by and construed in accordance with the domestic substantive laws of The Commonwealth of Massachusetts, without giving effect to any choice or conflicts of law rule or provision that would result in the application of the domestic substantive laws of any other jurisdiction.

14.4. This Agreement shall bind and inure to the benefit of the parties hereto and their respective successors and assigns, but no assignment or transfer hereof or of any rights or obligations hereunder shall be made by any party without the written consent of the other party. Nothing herein expressed or implied is intended or shall be construed to confer upon or give any person, firm or corporation, other than the parties hereto and their respective successors and assigns, any rights or remedies under or by reason of this Agreement.

14.5. A copy of the Declaration of Trust of the Acquiring Trust is on file with the Secretary of The Commonwealth of Massachusetts, and notice is hereby given that no trustee, officer, agent or employee of the Acquiring Trust shall have any personal liability under this Agreement, and that insofar as it relates to the Acquiring Fund, this Agreement is binding only upon the assets and properties of such Acquiring Fund.

[THE REST OF THIS PAGE IS INTENTIONALLY BLANK.]

14

IN WITNESS WHEREOF, each of the parties hereto has caused this Agreement to be executed as set forth below.

		On behalf of each Acquired Fund listed in Exhibit A
Attest:
By:	/s/ Ryan C. Larrenaga	By:	/s/ Michael G. Clarke
Name:	Ryan C. Larrenaga	Name:	Michael G. Clarke
Title:	Assistant Secretary	Title:	Treasurer
		On behalf of the Acquiring Fund listed in Exhibit A
Attest:
By:	/s/ Linda Roth-Wiszowaty	By:	/s/ Bruce H. Lauer
Name:	Linda Roth-Wiszowaty	Name:	Bruce H. Lauer
Title:	Assistant Secretary	Title:	Vice President, Secretary and Treasurer
		Solely for purposes of Sections 4.3, 4.4, 6.3 and 9.2 of the Agreement Columbia Management Investment Advisers, LLC
Attest:
By:	/s/ Ryan C. Larrenaga	By:	/s/ Christopher C. Thompson
Name:	Ryan C. Larrenaga	Name:	Christopher C. Thompson
Title:	Vice President	Title:	Senior Vice President

15

Exhibit A

Acquired Fund	Acquiring Fund
RiverSource Partners International Select Growth Fund	Columbia Acorn International
RiverSource Partners International Small Cap Fund	Columbia Acorn International

16

Exhibit B

Acquired Fund	Authorized Capital
RiverSource Partners International Select Growth Fund	10,000,000,000 shares
RiverSource Partners International Small Cap Fund	10,000,000,000 shares

17

Exhibit C

Acquiring Fund	Authorized Capital
Columbia Acorn International	Unlimited

18

EX-99.(12)

Drinker, Biddle & Reath LLP

August 15, 2011

Columbia Acorn International

c/o 227 W. Monroe Street, Suite 3000

Chicago, IL 60606

RiverSource Partners International Small Cap Fund

50606 Ameriprise Financial Center

H27/5228

Minneapolis, MN 55474

RiverSource Partners International Select Growth Fund

50606 Ameriprise Financial Center

H27/5228

Minneapolis, MN 55474

Re: Plan of Reorganization with respect to the RiverSource Partners

International Select Growth Fund, RiverSource Partners International

Small Cap Fund, and Columbia Acorn International dated December 20, 2010

Ladies and Gentlemen:

We have acted as counsel to Columbia Acorn International (the “Acquiring Fund”), a series of Columbia Acorn Trust, a Massachusetts business trust (the “Trust”), in connection with the transfer of all of the assets of the RiverSource Partners International Select Growth Fund and the RiverSource Partners International Small Cap Fund (together, the “Acquired Funds”), each a series of RiverSource International Managers Series, Inc., a Minnesota corporation (“RiverSource”) to the Acquiring Fund, in exchange solely for shares of the Acquiring Fund and its assumption of the Acquired Funds’ liabilities, followed by the distribution by each Acquired Fund to its shareholders of the Acquiring Fund shares (collectively, the “Reorganization”), pursuant to the Plan of Reorganization by and between the Acquired Funds and the Acquiring Fund, dated December 20, 2010 (the “Plan”). You have asked for our opinion on certain federal income tax consequences of the Reorganization. (All capitalized terms used but not otherwise defined in this letter shall have the meanings ascribed to them in the Plan.)

For purposes of this opinion, we have reviewed the Plan and such other documents and matters of law and fact as we have considered necessary or appropriate, and we have assumed, with your consent, the following:

(i) The Reorganization will be completed in the manner set forth in the Plan and in the combined proxy statement/prospectus (the “Proxy/Prospectus”) filed as part of the Registration Statement on Form N-14 of the Trust (File No. 333-170360) (the “Registration Statement”) to which this opinion is filed as an exhibit.

(ii) The representations contained in the letter of representation from Columbia Management Investment Advisers, LLC (“Columbia Management”) to us, dated as of this date, are true and complete.

(iii) The Acquired Funds and the Acquiring Fund will each qualify as a “regulated investment company” under section 851 of the Internal Revenue Code of 1986, as amended (the “Code”) for the current taxable year.

On the basis of the foregoing, it is our opinion that:

(1) the Reorganization will constitute a “reorganization” within the meaning of section 368(a) of the Code, and the Acquired Funds and the Acquiring Fund will each be a “party to a reorganization” within the meaning of section 3 68(b) of the Code;

(2) no Acquired Fund will recognize gain or loss (a) upon the transfer of its assets to the Acquiring Fund in exchange for Acquiring Fund shares and the assumption of the liabilities of the Acquired Funds or (b) upon the distribution of those shares to the shareholders of the Acquired Funds;

(3) the Acquiring Fund will recognize no gain or loss upon the receipt of the assets of the Acquired Funds in exchange for shares of the Acquiring Fund and the assumption of the liabilities of the Acquired Funds;

(4) the tax basis in the hands of the Acquiring Fund of each asset of each Acquired Fund transferred to the Acquiring Fund in the Reorganization will be the same as the basis of that asset in the hands of the Acquired Fund that held that asset immediately before the transfer;

(5) the holding period in the hands of the Acquiring Fund of each asset of each Acquired Fund transferred to the Acquiring Fund in the Reorganization will include the period during which that asset was held by the relevant Acquired Fund;

(6) the shareholders of the Acquired Funds will recognize no gain or loss upon their receipt of shares of the Acquiring Fund in exchange for shares of an Acquired Fund;

(7) the aggregate tax basis of the Acquiring Fund shares received by each shareholder of an Acquired Fund will equal the aggregate tax basis of the Acquired Fund shares surrendered by that shareholder in the Reorganization;

(8) the holding periods of the Acquiring Fund shares received by each shareholder of an Acquired Fund will include the holding periods of the Acquired Fund shares surrendered by that shareholder in the Reorganization, provided that such Acquired Fund shares are held by that shareholder as capital assets on the date of the Reorganization;

(9) the Acquired Funds’ final taxable years will end on the date of the

-2-

Reorganization, and

(10) the Acquiring Fund will succeed to and take into account the tax attributes of the Acquired Funds described in section 381 (c) of the Code, subject to the conditions and limitations specified in sections 381, 382, 383 and 384 of the Code and the Treasury Regulations thereunder.

The above opinions represent our best legal judgment, but they have no binding effect or official status of any kind, and no assurance can be given that contrary positions may not be taken by the IRS or a court concerning the issues. We express no opinion relating to any federal income tax matter except on the basis of the facts described above, and any changes in such facts could require a reconsideration and modification of this opinion. We also express no opinion regarding tax consequences under foreign, state or local laws. In issuing our opinion, we have relied solely upon existing provisions ofthe Code, existing and proposed regulations thereunder, and current administrative positions and judicial decisions. Such laws, regulations, administrative positions and judicial decisions are subject to change at any time. Any such changes could affect the validity of the opinions set forth above. Also, future changes in federal income tax laws and the interpretation thereof can have retroactive effect.

We hereby consent to the reliance of the Board of Directors of RiverSource on the foregoing opinions.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference to us under the heading “Information About the Reorganizations - Tax Status of the Reorganizations” in the Proxy-Prospectus. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act of 1933.

Very truly yours,

/s/ Drinker Biddle & Reath LLP

DRINKER BIDDLE & REATH LLP

-3-

EX-99.(13)(D)

COLUMBIA MANAGEMENT INVESTMENT SERVICES CORP.

225 Franklin Street

Boston, MA 02110

As of August 12, 2011

Columbia Acorn Trust

227 W. Monroe Street

Suite 3300

Chicago, Illinois 60606

Ladies and Gentlemen:

At a meeting of shareholders of RiverSource Partners International Select Growth Fund and RiverSource Partners International Small Cap Fund, each a series of RiverSource International Managers Series, Inc. (the “Acquired Funds”), held on April 27, 2011, shareholders approved the merger of the Acquired Funds into Columbia Acorn International (the “Fund”) (the “Reorganization”). The Reorganization is expected to close on or about August 12, 2011 (“Closing Date”).

In connection with the Reorganization, Columbia Management Investment Services Corp. (the “Transfer Agent”) hereby contractually undertakes, effective as of the Closing Date through August 14, 2013, as follows:

1. The Transfer Agent will waive a portion of the total annual Fund operating expenses attributable to transfer agency fees incurred by Class A shares in the amount equal to 0.04% of the Fund’s average daily net assets.

2. The Transfer Agent will waive a portion of the total annual Fund operating expenses attributable to transfer agency fees incurred by Class B shares of the Fund in the amount equal to 0.03% of the Fund’s average daily net assets.

3. The Transfer Agent will waive a portion of the total annual Fund operating expenses attributable to transfer agency fees incurred by Class C shares in the amount equal to 0.02% of the Fund’s average daily net assets.

This undertaking shall be binding upon any successors and assigns of the Transfer Agent.

Very truly yours,
COLUMBIA MANAGEMENT INVESTMENT SERVICES CORP.
By:	/s/    Steve Welsh
Name:	Steve Welsh
Title:	President

Agreed and accepted by

COLUMBIA ACORN TRUST

on behalf of its series Columbia Acorn International

By:	/s/    Bruce H. Lauer
Bruce H. Lauer
Vice President, Secretary and Treasurer