EXHIBIT 11

                                       April 6, 2001


Barr Rosenberg Series Trust
4 Orinda Way, Building E
Orinda, California 94563

            Re:  REGISTRATION STATEMENT ON FORM N-14
                 -----------------------------------

Ladies and Gentlemen:

This opinion is being furnished in connection with the Registration Statement
(the "Registration Statement") of Barr Rosenberg Series Trust (the "Series
Trust") on Form N-14 with respect to its AXA Rosenberg Value Market Neutral
Fund (the "Value Fund"), a series of the Series Trust, being filed by the
Series Trust today under the Securities Act of 1933, as amended (the "Act"),
relating to the proposed acquisition by the Value Fund of substantially all
of the assets of the Barr Rosenberg VIT Market Neutral Fund (the "Variable
Fund"), a series of the Barr Rosenberg Variable Insurance Trust (the "VIT"),
and the issuance of shares of beneficial interest of Institutional shares of
the Value Fund in connection therewith (the "Shares"), all in accordance with
the terms of the proposed Agreement and Plan of Reorganization by and between
the Series Trust, on behalf of the Value Fund, and the VIT, on behalf of the
Variable Fund (the "Agreement and Plan of Reorganization"), in substantially
the form included as an exhibit to the Registration Statement.

            We have examined: the Agreement and Plan of Reorganization; the
Series Trust's Second Amended and Restated Agreement and Declaration of
Trust, as amended to the date hereof (the "Series Trust Declaration of
Trust), on file in the offices of the Secretary of State of The Commonwealth
of Massachusetts and the City Clerk of the City of Boston; the By-Laws of the
Series Trust, as amended to the date hereof (the "Series Trust By-Laws") and
the Resolutions of the Board of Trustees of the Series Trust adopted at a
meeting held December 4, 2000. We have relied upon a certificate of an
officer of the Series Trust as to certain factual matters. We have also
examined such other documents and records as we have deemed necessary for the
purposes of this opinion.

            We have assumed, for purposes of this opinion, that, prior to the
date of the issuance of the Shares, the Agreement and Plan of Reorganization
will have been duly executed and delivered by each party thereto and will
constitute a legal, valid and binding obligation of the Series Trust, on
behalf of the Value Fund, and the VIT, on behalf of the Variable Fund.

            Based upon the foregoing, we are of the opinion that:




            1. The Series Trust is a duly organized and validly existing
unincorporated association under the laws of The Commonwealth of
Massachusetts and is authorized to issue an unlimited number of its shares of
beneficial interest.

            2. When issued in accordance with the Agreement and Plan of
Reorganization, the Shares will be validly issued, fully paid and
nonassessable by the Series Trust.

            The Series Trust is an entity of the type commonly known as a
"Massachusetts business trust." Under Massachusetts law, shareholders could,
under certain circumstances, be held personally liable for the obligations of
the Series Trust. However, the Series Trust Declaration of Trust disclaims
shareholder liability for acts or obligations of the Series Trust and
requires that a notice of such disclaimer be given in each agreement,
obligation or instrument entered into or executed by the Series Trust or its
Trustees. The Series Trust Declaration of Trust provides for indemnification
out of Value Fund property for all loss and expenses of any shareholder held
personally liable solely by reason of being or having been a shareholder of
the Value Fund. Thus, the risk of a shareholder's incurring financial loss
on account of shareholder liability is limited to circumstances in which the
Value Fund would be unable to meet its obligations.

            We understand that this opinion is to be used in connection with
the registration of the Shares for offering and sale pursuant to the Act. We
consent to the filing of this opinion with and as part of the Registration
Statement.

                                       Very truly yours,


                                       Ropes & Gray