EXHIBIT 3

                                [BBH LETTERHEAD]

                                           June 4, 2003

GMO Trust
40 Rowes Wharf
Boston, MA 02110

Re:   Custodian Agreement (the "Agreement"), dated as of June 29, 2001, between
      GMO Trust (the "Trust"), on behalf of certain series of the Trust as set
      forth in the Agreement (each, a "Fund"), and Brown Brothers Harriman & Co.
      (the "Custodian").

Ladies and Gentlemen:

         Pursuant to Section 12.3 of the Agreement, this letter is intended to
supplement the Agreement in connection with recently adopted amendments to Rule
17f-4 under the Investment Company Act of 1940, as amended ("Rule 17-4"),
governing investment companies' use of securities depositories. Capitalized
terms used, but not otherwise defined herein, shall have the meanings ascribed
to them in the Agreement. The terms "financial assets," "securities
entitlements," "securities intermediary," "securities depository," and
"intermediary custodian," as used herein, shall have the same meaning as when
such terms are used in Rule 17f-4.

         The Custodian hereby agrees to the following:

         (1)      In addition to, and not in lieu of, any standard of care set
                  forth in the Agreement, the Custodian shall be obligated to
                  exercise due care in accordance with reasonable commercial
                  standards when placing and maintaining financial assets
                  corresponding to a Fund's securities entitlements with a
                  securities depository or an intermediary custodian;

         (2)      In addition to the Custodian's obligations under Section 11 of
                  the Agreement, the Custodian shall provide, promptly upon
                  request by the Trust, such reports as are available regarding
                  its internal accounting controls and financial strength; and

         (3)      In addition to, and not in lieu of, any standard of care set
                  forth in the Agreement that is applicable to an intermediary
                  custodian appointed by the Custodian pursuant to the terms of
                  the Agreement, any such intermediary custodian shall be
                  obligated, pursuant to the terms of its agreement or other
                  arrangement with the Custodian, at a minimum to exercise due
                  care in accordance with reasonable commercial standards in
                  discharging its duty as a securities intermediary to obtain
                  and thereafter maintain financial assets, corresponding to the
                  security entitlements of its entitlement holders (as defined
                  in U.C.C. Section 8-102(a)(7) (2002)).

         This letter agreement shall constitute an addendum to the Agreement
and, as such, a binding agreement between the Trust, on behalf of the Funds, and
the Custodian in accordance with its terms. The terms of this letter agreement
shall be effective as of March 28, 2003.





                                       Sincerely,

                                       BROWN BROTHERS HARRIMAN & CO.

                                       By: /S/ Timothy J. Connelly
                                           --------------------------------
                                               Name: Timothy J. Connelly
                                               Title: Partner

The foregoing is hereby
accepted and agreed.

GMO TRUST, on behalf of the Funds

By: /S/ Elaine M. Hartnett
    ---------------------------------
        Name: Elaine M. Hartnett
        Title: Vice President and Secretary