Ex-99.(d)(90)

EXhibit (d)(90)
                 AMENDMENT TO INVESTMENT SUB-ADVISORY AGREEMENT

         AMENDMENT made as of December 1, 2004 to the Investment Sub-Advisory
Agreement made as of the 1st day of May 2003 (the "Agreement") between Travelers
Asset Management International Company LLC ("TAMIC") and Pioneer Investment
Management Inc. (the "Sub-Adviser").

                                   WITNESSETH:

         WHEREAS, TAMIC and the Sub-Adviser have entered into an Agreement with
respect to the Pioneer Fund Portfolio of The Travelers Series Trust;

         WHEREAS, the TAMIC and the Sub-Adviser desire to amend the Agreement to
change the investment subadvisory fee;

         NOW THEREFORE, in consideration of the mutual promises set forth below,
TAMIC and the Sub-Adviser hereby agree to amend paragraph 6 to this Agreement to
read as follows:

         6. COMPENSATION

               In consideration of the services rendered, the facilities
               furnished, and the expenses assumed pursuant to this Agreement,
               TAMIC will pay the Sub-Adviser a monthly fee equivalent on an
               annual basis to the following:

               ANNUAL                                  AGGREGATE NET ASSET VALUE
           MANAGEMENT FEE                                 OF THE PORTFOLIO
               0.375%         of the first                   $250,000,000
               0.325%         of the next                    $250,000,000
               0.300%         of the next                    $500,000,000
               0.275%         of the next                   $1,000,000,000
               0.225%         of amounts over               $2,000,000,000


               The advisory fees will be deducted on each valuation date. The
               Sub-Adviser shall have no right to obtain compensation directly
               from the Trust for services provided hereunder and agrees to look
               solely to TAMIC for payment of fees due. The fee for the period
               from the Effective Date (defined below) of the Agreement to the
               end of the month during which the Effective Date occurs shall be
               prorated according to the proportion that such period bears to
               the full monthly period. Upon any termination of this Agreement
               before the end of a month, the fee for such part of that month
               shall be prorated according to the proportion that such period
               bears to the full monthly period and shall be payable upon the
               date of termination of this Agreement. For the purpose of
               determining fees payable to TAMIC, the value of the Portfolio's
               net assets shall be computed at the times and in the manner
               specified in the then current Prospectus and/or the SAI.



         IN WITNESS WHEREOF, this Amendment to the Agreement has been executed
by a duly authorized representative of each of the parties hereto as of the date
of the Amendment first set forth above.

                                    Travelers Asset Management International
                                    Company LLC

                                    By: /s/ Mark Remington
                                        ------------------


                                    Pioneer Investment Management Inc.


                                    By: /s/ Mark D. Goodwin
                                        -------------------