AMENDMENT #4 TO PARTICIPATION AGREEMENT DATED AS OF MARCH 21,2000 (as amended and supplemented from time to time)

                          AMENDMENT #4 TO PARTICIPATION AGREEMENT
                                 DATED AS OF MARCH 21,2000
                      (as amended and supplemented from time to time)


                                           AMONG

                  ALLMERICA FINANCIAL LIFE INSURANCE AND ANNUITY COMPANY,

                          INVESCO VARIABLE INVESTMENT FUNDS, INC.,

                                 INVESCO FUNDS GROUP, INC.,

                                            AND

                                 INVESCO DISTRIBUTORS, INC.

WHEREAS,  Allmerica  Financial  Life  Insurance  and  Annuity  Company,  INVESCO
Variable  Investment Funds, Inc. and INVESCO  Distributors,  Inc. entered into a
Fund Participation Agreement on March 21,200O; and

WHEREAS,  the  parties  desire to amend the  Participation  Agreement  by mutual
written consent;

NOW THEREFORE, the parties to hereby agree that Schedule A to the Participation
Agreement is amended to read in its entirety as follows:

                                   SCHEDULE A

The following Separate Accounts and Associated  Contracts of Allmerica Financial
Life Insurance and annuity Company are permitted in accordance with the
provisions  of this  Agreement  to invest  in  Portfolios  of the Fund  shown in
Schedule B:

CONTRACTS FUNDED BY SEPARATE ACCOUNT            NAME OF SEPARATE ACCOUNT
------------------------------------            ------------------------
Allmerica ExecAnuity Plus 91                    Separate Account VA-K

Allmerica ExecAnuity Plus 91                    Separate Account VA-K

Allmerica Advantage                             Separate Account VA-K

Allmerica Ultimate Advantage                    Separate Account VA-K

Allmerica Accumulator                           Separate Account VA-K

Fund Quest                                      Separate Account VA-K

Allmerica Value Generation ("Annuity Scout")    Separate Account VA-K

Select Reward                                   Select Separate Account

Select Resource                                 Select Separate Account

Select Charter                                  Select Separate Account

Select Secondary Markets                        Select Separate Account


All terms and conditions of the  Participation  Agreement and Schedules  thereto
shall continue in full force and effect except as amended herein


IN WITNESS WHEREOF, each of the parties has caused this Amendment to be executed
in its  name  and on its  behalf  by its duly  authorized  representative  as of
January 1, 2001.

                                    ALLMERICA FINANCIAL LIFE INSURANCE AND
                                    ANNUITY COMPANY

                                    By: /s/  Xxxxxxx X. Xxxxxx
                                        ----------------------
                                        Xxxxxxx X. Xxxxxx, President

                                    INVESCO VARIABLE INVESTMENT FUNDS, INC.

                                    By: /s/ Xxxxxx X. Xxxxxx
                                        --------------------
                                        Xxxxxx X. Xxxxxx, Treasurer

                                    INVESCO FUNDS GROUP, INC.

                                    By: /s/ Xxxxxx X. Xxxxxx
                                        --------------------
                                        Xxxxxx X. Xxxxxx, Senior Vice President

                                    INVESCO DISTRIBUTORS, INC.

                                    By: /s/ Xxxxxx X. Xxxxxx
                                        --------------------
                                        Xxxxxx X. Xxxxxx, Senior Vice President