Unassociated Document

August 13, 2009

Investment Managers Series Trust

803 West Michigan Street

Milwaukee, WI 53233

Ladies and Gentlemen:

We have acted as counsel to Investment Managers Series Trust, a Delaware statutory trust (the “Trust”), in connection with the Trust’s Registration Statement filed on Form N–14 with the Securities and Exchange Commission (the “Registration Statement”) relating to the issuance by the Trust of Class A, Class C, and Institutional Class shares of beneficial interest (the “Shares”) of the Liberty Street Horizon Fund series of the Trust (the “Fund”) pursuant to an Agreement and Plan or Reorganization by and among the Trust, Forum Funds, and Liberty Street Advisors, Inc., dated August 10, 2009 (the “Reorganization Agreement”).

In connection with this opinion, we have assumed the authenticity of all records, documents and instruments submitted to us as originals, the genuineness of all signatures, the legal capacity of natural persons and the conformity to the originals of all records, documents and instruments submitted to us as copies. We have based our opinion upon our review of the following records, documents and instruments:

(a) the Trust’s Certificate of Trust as filed with the Delaware Secretary of State on February 15, 2005, as amended on June 2, 2005 and December 5, 2007, certified to us by an officer of the Trust as being true and complete on the date hereof;

(b) the Trust’s Agreement and Declaration of Trust dated February 15, 2005, as amended on May 27, 2005, December 3, 2007, and March 25, 2009 (the “Declaration of Trust”), certified to us by an officer of the Trust as being true and complete on the date hereof;

(d) resolutions of the Trust’s Board of Trustees adopted on March 25, 2009, June 23, 2009 and August 12, 2009, authorizing the creation of the Fund, the issuance of the Shares and the execution of the Reorganization Agreement, certified to us by an officer of the Trust as being true and complete and in effect on the date hereof;

(e) the Registration Statement;

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August 13, 2009

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(f) the Reorganization Agreement;

(g) a certificate of an officer of the Trust concerning certain factual matters relevant to this opinion; and

(h) a certificate issued by the Delaware Secretary of State that the Trust is duly formed under the laws of the State of Delaware and is in good standing, dated as of August 11, 2009.

Our opinion below is limited to the statutory trust law of the State of Delaware. We are not licensed to practice law in the State of Delaware, and we have based our opinion below solely on our review of Chapter 38 of Title 12 of the Delaware Code (the “Delaware Statutory Trust Act”) and the case law interpreting the Delaware Statutory Trust Act as reported in Delaware Laws Affecting Business Entities (Matthew Bender & Company, Inc., 2009 Spring Edition) as updated on Westlaw through August 12, 2009. We have not undertaken a review of other Delaware law or of any administrative or court decisions in connection with rendering this opinion. We disclaim any opinion as to any law other than the statutory trust law of the State of Delaware as described above, and we disclaim any opinion as to any statute, rule, regulation, ordinance, order or other promulgation of any federal, regional or local governmental authority.

Based on the foregoing and our examination of such questions of law as we have deemed necessary and appropriate for the purpose of this opinion, and assuming that (i) all of the Shares will be issued and sold for consideration at their net asset value on the date of their issuance in accordance with statements in the Registration Statement and in accordance with the Reorganization Agreement and the Declaration of Trust, (ii) all consideration for the Shares will be actually received by the Trust, and (iii) all applicable securities laws will be complied with, then it is our opinion that, when issued and sold by the Trust, the Shares will be legally issued, fully paid and nonassessable by the Trust.

This opinion is rendered to you in connection with the Registration Statement and is solely for your benefit. This opinion may not be relied upon by you for any other purpose, or relied upon by any other person, firm, corporation or other entity for any purpose, without our prior written consent. We disclaim any obligation to advise you of any developments in areas covered by this opinion that occur after the date of this opinion.

We hereby consent to (i) the reference to our firm as Legal Counsel in the Registration Statement and (ii) the filing of this opinion as an exhibit to the Registration Statement.

Very truly yours,

/s/PAUL, HASTINGS, JANOFSKY & WALKER LLP