GMO TRUST
                     GRANTHAM, MAYO, VAN OTTERLOO & CO. LLC
                                 40 ROWES WHARF
                                BOSTON, MA 02110

                                                       January __, 2005

Investors Bank & Trust Company
Financial Product Services
200 Clarendon Street
Boston, Massachusetts 02116

Re:   Amendment to the Custodian Agreement, dated August 1, 1991, by and among
      GMO Trust, Grantham, Mayo, Van Otterloo & Co. LLC (formerly, Grantham,
      Mayo, Van Otterloo & Co.) ("GMO") and Investors Bank & Trust Company
      ("IBT"), as amended (the "Custodian Agreement") and the Amended and
      Restated Delegation Agreement, dated as of June 29, 2001, by and between
      IBT and GMO Trust, and on behalf of certain of its series of the Trust, as
      amended (the "Delegation Agreement").

Ladies and Gentlemen:

      GMO Trust hereby notifies you that it has established an additional series
of shares, namely, the "GMO Alternative Asset Opportunity Fund" (the "New
Fund"). The Trust (as defined in each of the Custodian Agreement and the
Delegation Agreement) desires that you serve as (i) custodian of the assets of
the New Funds under the terms of the Custodian Agreement and (ii) delegate with
respect to the assets of the New Fund under the terms of the Delegation
Agreement.

      If you agree to so serve as the custodian and delegate for the New Fund,
kindly sign and return to the Trust the enclosed counterpart hereof, whereupon
the New Fund shall be deemed a "Fund" under each of the Custodian Agreement and
the Delegation Agreement. This letter agreement shall constitute an amendment to
each of the Custodian Agreement and the Delegation Agreement and, as such, a
binding agreement among the Trust, GMO (only in the case of the Custodian
Agreement) and you in accordance with its terms.

                                Sincerely,

                                GMO TRUST

                                By: ____________________________________
                                    Name: Elaine M. Hartnett
                                    Title: Vice President and Secretary

                                GRANTHAM, MAYO, VAN OTTERLOO & CO. LLC

                                By: ____________________________________
                                    Name: Elaine M. Hartnett
                                    Title: Associate General Counsel




Investors Bank & Trust Company                                  January __, 2005

The foregoing is hereby
accepted and agreed.

INVESTORS BANK & TRUST COMPANY

By: __________________________________
    Name:
    Title:

                                      -2-