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                                                         EXHIBIT 10.20




                                                December 29, 1997



Paul Duncan
76 Washington Drive
Sudbury, MA  01776

     Re:  Reebok Supplemental Executive Retirement Plan ("SERP")

Dear Paul:

      As you know, Reebok would like to retain you as a part-time employee
during 1998. In order to induce you to remain as a part-time employee and insure
that the compensation you will receive from Reebok's SERP will not be negatively
affected by you remaining a part-time employee, Reebok hereby agrees with you
that for purposes of determining your Final Average Total Compensation (as
defined in Section 4(e)(1) of the SERP) under the SERP plan, we will use the
average of your Total Compensation (as such term is defined in the SERP) for the
three calendar years during the period 1993 thorough 1997 (inclusive) in which
you had the highest Total Compensation.

      This letter agreement shall constitute an amendment of the SERP with
respect to your participation therein.

      If the foregoing reflects your agreement, please sign below.

                                   Very truly yours,

                                   REEBOK INTERNATIONAL LTD.


                                   By:/s/ BARRY NAGLER

Agreed to by:


/s/ PAUL R. DUNCAN
Paul Duncan