<PAGE>
EXHIBIT 23(a)(5)
BARR ROSENBERG SERIES TRUST
AMENDMENT NO. 4 TO
AGREEMENT AND DECLARATION OF TRUST
The undersigned, being all of the trustees of Barr Rosenberg Series
Trust, a Massachusetts business trust created and existing under an Agreement
and Declaration of Trust dated April 1, 1988, as amended, a copy of which is
on file in the Office of the Secretary of The Commonwealth of Massachusetts
(the "Trust"), having determined that the creation of a new Series of the
Trust is consistent with the fair and equitable treatment of all
Shareholders, do hereby direct that this Amendment No. 4 be filed with the
Secretary of The Commonwealth of Massachusetts and do hereby consent to and
adopt the following amendment to the Agreement and Declaration of Trust:
1. The first sentence of Section 6 of Article III of the Second
Amended and Restated Agreement and Declaration of Trust is amended and
restated in its entirety to read as follows:
"Without limiting the authority of the Trustees set forth in
Section 5, INTER ALIA, to establish and designate any further Series
or Classes of Shares or to modify the rights and preferences of any
Series or Class, the "AXA Rosenberg Japan Fund" (formerly the Japan
Series), "AXA Rosenberg U.S. Small Capitalization Fund" (formerly the
U.S. Small Capitalization Series and, prior to that, the Small
Capitalization Series), "AXA Rosenberg International Small
Capitalization Fund" (formerly the International Small Capitalization
Series), "AXA Rosenberg Value Market Neutral Fund" (formerly the Barr
Rosenberg Market Neutral Fund), "AXA Rosenberg Double Alpha Market
Fund" (formerly the Barr Rosenberg Double Alpha Market Fund), "AXA
Rosenberg Select Sectors Market Neutral Fund" (formerly the Barr
Rosenberg Select Sectors Market Neutral Fund), "AXA ROSENBERG ENHANCED
500 FUND," "AXA ROSENBERG INTERNATIONAL EQUITY FUND," "AXA ROSENBERG
MULTI-STRATEGY MARKET NEUTRAL FUND" AND "AXA ROSENBERG U.S. DISCOVERY
FUND" shall be, and are hereby, established and designated; and with
respect to the AXA Rosenberg U.S. Small Capitalization Fund, the
Institutional Shares Class, Adviser Shares Class and Investor Shares
Class, which may be issued by such Series from time to time, shall be,
and are hereby, established and designated, and with respect to the
AXA Rosenberg Japan Fund, the Institutional Shares Class and Investor
Shares Class, which
<PAGE>
may be issued by such Series from time to time, shall be, and are
hereby, established and designated, and with respect to the AXA
Rosenberg International Small Capitalization Fund, AXA Rosenberg Value
Market Neutral Fund, AXA Rosenberg Double Alpha Market Fund, AXA
Rosenberg Select Sectors Market Neutral Fund, AXA Rosenberg Enhanced
500 Fund, AXA Rosenberg International Equity Fund, AXA Rosenberg
Multi-Strategy Market Neutral Fund and AXA Rosenberg U.S. Discovery
Fund, the Institutional Shares Class, Investor Shares Class, Class A,
Class B and Class C, which may be issued by each such Series from time
to time, shall be, and are hereby, established and designated, all of
which Classes shall have the respective rights and preferences as are
set forth in the Plan attached as Exhibit 3.6 hereto as such Plan may
be amended from time to time by the Board of Trustees."
The foregoing amendment shall become effective upon execution by the
undersigned trustees. This amendment may be executed in multiple
counterparts, each of which shall be deemed an original, but all of which
taken together shall constitute one instrument.
-2-
<PAGE>
IN WITNESS WHEREOF, each of the undersigned Trustees as aforesaid do
hereto set their hands this 30th day of September, 2000.
NILS HAKANSSON
----------------------------------------
Nils Hakansson
KENNETH REID
----------------------------------------
Kenneth Reid
WILLIAM F. SHARPE
----------------------------------------
William F. Sharpe
DWIGHT M. JAFFEE
----------------------------------------
Dwight M. Jaffee
-3-
