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      As filed with the Securities and Exchange Commission on June 7, 2002
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                   SCHEDULE TO
             Tender Offer Statement under Section 14(d)(1) or 13(e)
                     Of the Securities Exchange Act of 1934
                                (AMENDMENT NO. 2)

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                               TRENWICK GROUP LTD.
                       (Name of Subject Company -- Issuer)

                               TRENWICK GROUP LTD.
                       (Name of Filing Person -- Offeror)

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    OPTIONS TO PURCHASE COMMON SHARES, PAR VALUE $.10 PER SHARE, ISSUED UNDER
      THE TRENWICK GROUP INC. 1989 STOCK PLAN, THE TRENWICK GROUP INC. 1993
     STOCK OPTION PLAN, THE CHARTWELL RE CORPORATION 1993 STOCK OPTION PLAN,
     THE CHARTWELL RE CORPORATION 1997 OMNIBUS STOCK INCENTIVE PLAN AND THE
                        LASALLE RE HOLDINGS LIMITED 1996
                            LONG-TERM INCENTIVE PLAN
                         (Title of Class of Securities)

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                                 JOHN V. DEL COL
                                    SECRETARY
                               TRENWICK GROUP LTD.
                              CONTINENTAL BUILDING
                                25 CHURCH STREET
                             HAMILTON HM 12, BERMUDA
                             TELEPHONE: 441-292-4985
                             FACSIMILE: 441-292-2656
      (Name, address and telephone number of person authorized to receive
             notices and communications on behalf of Filing Person)

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                                   A COPY TO:
                                JAMES R. CAMERON
                                BAKER & MCKENZIE
                                 805 THIRD AVE.
                            NEW YORK, NEW YORK 10022
                             TELEPHONE: 212-891-3930
                             FACSIMILE: 212-891-3835



Check the appropriate boxes below to designate any transactions to which the
statement relates:

|_|  third-party tender offer subject to Rule 14d-1.
|X|  issuer tender offer subject to Rule 13e-4.
|_|  going-private transaction subject to Rule 13e-3.
|_|  amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results
of the tender offer: |_|

      This Amendment No. 2 amends and supplements the Tender Offer Statement on
Schedule TO, dated May 16, 2002, and amended by Amendment No. 1, dated May 28,
2002 (the "Tender Offer Statement") filed by Trenwick Group Ltd., a Bermuda
corporation ("Trenwick"), relating to the offer by Trenwick to exchange
outstanding employee options to purchase its common shares granted under the
Trenwick Group Inc. 1989 Stock Plan, the Trenwick Group Inc. 1993 Stock Option
Plan, the Chartwell Re Corporation 1993 Stock Option Plan, the Chartwell Re
Corporation 1997 Omnibus Stock Incentive Plan and the LaSalle Re Holdings
Limited 1996 Long-Term Incentive Plan for new options to purchase its common
shares, upon the terms and subject to the conditions set forth in the Offer to
Exchange, which was attached to the Tender Offer Statement, as Exhibit 99.2, as
amended.

ITEM 4. Terms of the Transaction.

      (a) The description of the terms of the offer set forth in the Offer to
Exchange under the heading "The Offer: 7. Conditions of the Offer" is hereby
amended to delete from the third line of clause (c)(8) the term "10%" and to
replace it with "20%".

ITEM 12. Exhibits.

      Item 12 of the Tender Offer Statement is hereby amended to add a reference
to Exhibit 99.9, which is attached hereto, as follows:

            99.9  Notice of Waiver of and Amendment to Condition to Offer to
                  Exchange.



                                    SIGNATURE

      After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this Amendment No. 2 to Schedule TO is true,
complete and correct.

Dated: June 7, 2002

                                        TRENWICK GROUP LTD.


                                              By: /s/ John V. Del Col
                                                  ------------------------------
                                                  Name: John V. Del Col
                                                  Title: Secretary