EXHIBIT 99.4

[LOGO] TRENWICK GROUP LTD.

                          STOCK OPTION EXCHANGE PROGRAM

                                 CHANGE PACKAGE

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        THE WITHDRAWAL RIGHTS EXPIRE AT 11:59 P.M., EASTERN TIME (U.S.),
                 ON JUNE 14, 2002, UNLESS THE OFFER IS EXTENDED

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      This Change Package consists of three parts: (1) Change of Election
Information; (2) Change Instructions; and (3) Change Form.

                         CHANGE OF ELECTION INFORMATION

To Trenwick Group Ltd. ("Trenwick"):

      I have received, read, and understand (i) the Stock Option Exchange
Program Tender Offer Statement dated May 16, 2002 (the "Offer to Exchange");
(ii) the Election Package (together, as they may be amended from time to time,
constituting the "Offer"); and (iii) this Change Package. I have submitted an
election to accept Trenwick's offer to exchange all of my Current Options for
New Options. I now wish to change that election and withdraw my election to
participate in the Offer and the tender of my Current Options. I understand and
acknowledge that:

(1)   By withdrawing my election to participate in the Offer and the tender of
      my Current Options, I will not receive any New Options pursuant to the
      Offer and I will keep my Current Options. These Current Options will
      continue to be governed by the Option Plan under which they were granted
      and by the existing option agreements between Trenwick and me.

(2)   I can only change my election to participate in the Offer one time. Thus,
      if I change my election with respect to the tender of my Current Options,
      I may not again tender my Current Options under the Offer.

(3)   I must change my election with respect to all of my tendered Current
      Options. I may not change my election with respect to only a portion of my
      tendered Current Options.

(4)   I have read this Change Package and by withdrawing my election to
      participate in the Offer and the tender of my Current Options, I
      understand that I am bound by the additional terms and conditions in this
      Change Package.

(5)   Trenwick has advised me to consult with my own advisors (including my own
      tax advisors) as to the consequences of withdrawing my election to
      participate in the Offer and the tender of my Current Options.

(6)   All authority in the Change Form will survive my death or incapacity.


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(7)   Any capitalized term used in this Change Package, which is not defined
      within this Change Package, will have the same meaning for this Change
      Package as that given to it in the Offer to Exchange.

(8)   I understand that (i) the Offer to Exchange and (ii) the Election Package
      contain all of the terms of the Offer in their entirety, and that I have
      not relied on any other documents, other than this Change Package, or oral
      representations from Trenwick or any of its subsidiaries or affiliates or
      their respective officers, directors, employees, representatives or agents
      in deciding to withdraw my election to participate in the Offer and the
      tender of my Current Options.


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                               CHANGE INSTRUCTIONS

1. Delivery of Change Form

      You may change your election to participate in the Offer only one time by
submitting your change no later than 11:59 P.M., Eastern Time (U.S.), on June
14, 2002 (or such later date and time if Trenwick extends the expiration of the
Offer).

      You must change your election with respect to all of your tendered Current
Options; you may not change your election with respect to only a portion of your
Current Options. Also, if you change your election, you may not again tender
your Current Options under the Offer.

      To change your election, Trenwick must receive your change of election in
one of the following two ways:

            o     Fax. You may change your election by faxing a properly
                  completed, signed and dated Change Form to the following
                  number: 203-353-5550.

            o     Mail. You may change your election by mailing a properly
                  completed, signed and dated Change Form in a stamped envelope
                  to the following address: Trenwick Group Ltd., c/o Trenwick
                  Services Inc., One Canterbury Green, Stamford, CT 06901,
                  U.S.A., Attn: Legal Department.

      A change of election may not be rescinded and any election of tendered
Current Options that is changed will thereafter not be deemed properly tendered
for purposes of the Offer.

      The method by which you change your election to participate in the Offer
is at your discretion and risk, and your change will be considered effective
only when actually received by Trenwick. If you elect to deliver your Change
Form by mail to the address listed above, Trenwick recommends that you use
certified mail with return receipt requested. Delivery by e-mail will not be
accepted. In all cases, you should allow sufficient time to ensure timely
delivery.

2. Signatures on Change Form

      If the Change Form is signed by the Eligible Employee who tendered the
Current Options to be withdrawn, the signature must be made by such employee.

      If the Change Form is signed by a trustee, executor, administrator,
guardian, attorney-in-fact, officer of a corporation or other person acting in a
fiduciary or representative capacity, such person should so indicate when
signing, and submit proper evidence satisfactory to Trenwick of the authority of
such person so to act with the Change Form.

3. Other Information on Change Form

      In addition to signing and dating the Change Form, you must print your
name in the space provided unless this information already appears on the form.

      Except to the extent Trenwick is required or permitted by law, the
information which you provide for withdrawing your acceptance of participating
in the Offer and the tender of your Current Options will be used solely for the
purposes of administration of the Offer.


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4. Requests for Assistance or Additional Copies

      Any questions or requests for assistance or additional copies of the Offer
of Exchange or this Change Package may be directed to assistance or Trenwick
Group Ltd., c/o Trenwick Services Inc., One Canterbury Green, Stamford, CT,
06901, U.S.A.; telephone: (203) 353-5500. Copies will be furnished at Trenwick's
expense.

5. Irregularities

      All questions as to the validity, form, eligibility (including time of
receipt) and acceptance of the Change Form will be determined by Trenwick in its
discretion, which determination will be final and binding on all parties.
Trenwick reserves the right to reject any change of election it determines not
to be in proper form or the acceptance of which may, in the opinion of
Trenwick's counsel, be unlawful. Trenwick also reserves the right to waive any
of the conditions of the Offer and any defect or irregularity in a change of
election, and Trenwick's interpretation of the terms of the Offer and the terms
of this Change Package will be final and binding to all parties. No change of
election will be deemed to be properly made until all defects and irregularities
have been cured or waived. Unless waived, any defects or irregularities in
connection with a change of election must be cured within such time as Trenwick
will determine. Neither Trenwick nor any other person is or will be obligated to
give notice of any defects or irregularities in a change of election, and no
person will incur any liability for failure to give any such notice.

6. Additional Documents to Read

      In addition to this Change Package, you should also carefully read the
Offer of Exchange and the Election Package before you decide to withdraw your
election to participate in the Offer.


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[LOGO] TRENWICK GROUP LTD.

                    STOCK OPTION EXCHANGE PROGRAM CHANGE FORM

Name

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      Your change of election to participate in the Stock Option Exchange
Program must be received by 11:59 P.M. Eastern Time (U.S.), Friday, June 14,
2002 (unless the election period is extended by Trenwick). Your change in
election will not be accepted if received after this time. If you want to change
your election, you must do so by faxing or mailing this Change Form.

      IF YOU CHANGE YOUR ELECTION, YOU ARE REVOKING YOUR ELECTION TO PARTICIPATE
IN THE STOCK OPTION EXCHANGE PROGRAM AND WILL NOT AGAIN BE ELIGIBLE TO
PARTICIPATE IN THE PROGRAM.

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                               CHANGE OF ELECTION

      I have received, read, and understand (i) the Stock Option Exchange
Program Tender Offer Statement dated May 16, 2002 (the "Offer to Exchange");
(ii) the Election Package (together, as they may be amended from time to time,
constituting the "Offer"); and (iii) the Change Package. I have submitted an
election to accept Trenwick's offer to exchange all of my Current Options for
New Options. I now wish to change that election and withdraw my election to
participate in the Offer and the tender of my Current Options. I understand that
by properly completing, signing, dating and delivering this Change Form, I will
withdraw my election to participate in the Offer and the tender of my Current
Options. By withdrawing my election to participate in the Offer, I will not
receive any New Options pursuant to the Offer and I will keep my Current
Options. These Current Options will continue to be governed by the Option Plan
under which they were granted and by the existing option agreements between
Trenwick and me. I understand that I can only change my election to participate
in the Offer one time. THUS, IF I CHANGE MY ELECTION WITH RESPECT TO THE TENDER
OF MY CURRENT OPTIONS BY PROPERLY SUBMITTING THIS FORM I MAY NOT AGAIN
PARTICIPATE IN THE OFFER AND TENDER MY CURRENT OPTIONS.

      I withdraw my election to participate in the Offer and the tender of my
Current Options.

         Signature _____________________                Date ___________________

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            WHEN SUBMITTING YOUR ELECTION FORM - ONLY SEND THIS PAGE

            Fax Completed Form to:                  Mail Completed Form to:
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            203-353-5550                            Trenwick Group Ltd.
                                                    c/o Trenwick Services Inc.
                                                    One Canterbury Green
                                                    Stamford, CT  06901, U.S.A.
                                                    Attn: Legal Department


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