Exhibit 99.1

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

I, Stephen H. Binet, President and Chief Executive Officer of Trenwick America
Corporation, hereby certify to the best of my knowledge and belief that this
Annual Report on Form 10-K fully complies with the requirements of Section 13(a)
or 15(d) of the Securities and Exchange Act of 1934 (15 U.S.C. 78m(a) or 78o(d))
and that the information contained in this Annual Report on Form 10-K fairly
represents, in all material respects, the financial condition and results of
operations of Trenwick America Corporation.

Date:  April 9, 2003


/s/ Stephen H. Binet
- --------------------------------------
     Stephen H. Binet
President and Chief Executive Officer