Exhibit 99.1

                    CERTIFICATION BY CHIEF EXECUTIVE OFFICER
                                   PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Trenwick America Corporation (the
"Company") on Form 10-Q for the period ending September 30, 2002 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Stephen H. Binet, President and Chief Executive Officer of the Company, certify,
pursuant to 18, U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that, to his knowledge:

         (1) The Report fully complies with the requirements of section 13(a) or
15(d) of the Securities Exchange Act of 1934; and

         (2) The information contained in the Report fairly presents, in all
material respects, the financial condition and result of operations of the
Company.

/s/ Stephen H. Binet

Stephen H. Binet
President and
Chief Executive Officer
November 14, 2002