Exhibit 99.7

                   SEVENTH AMENDMENT TO THE HOLDINGS GUARANTY

            SEVENTH AMENDMENT TO THE HOLDINGS GUARANTY (the "Seventh
Amendment"), dated as of March 7, 2003, among TRENWICK GROUP LTD., a company
organized under the laws of Bermuda ("Holdings") and the Banks party to the
Credit Agreement referred to below. Unless otherwise defined herein, capitalized
terms used herein and defined in the Holdings Guaranty referred to below are
used herein as so defined.

                              W I T N E S S E T H :
                              - - - - - - - - - -

            WHEREAS, Trenwick America Corporation, a Delaware corporation (the
"Borrower"), Trenwick Holdings Ltd., a company organized under the laws of the
United Kingdom (the "Trenwick Holdings"), the lending institutions from time to
time party thereto (each a "Bank" and, collectively, the "Banks"), Wachovia
Bank, National Association (f/k/a First Union National Bank), as Syndication
Agent (the "Syndication Agent"), Fleet National Bank, as Documentation Agent
(the "Documentation Agent"), and JPMorgan Chase Bank (f/k/a The Chase Manhattan
Bank), as Administrative Agent (the "Administrative Agent"), are party to a
Credit Agreement, dated as of November 24, 1999 and amended and restated as of
September 27, 2000 (as the same has been amended, modified or supplemented to,
but not including, the date hereof, the "Credit Agreement");

            WHEREAS, Holdings and the Administrative Agent entered into a
Holdings Guaranty, dated as of September 27, 2000 (as the same has been amended,
modified or supplemented to, but not including, the date hereof, the "Holdings
Guaranty") in order to induce the Banks to make Loans to the Borrower and issue
Letters of Credit for the account of the Account Party and Guaranteed Creditors
(and Lending Affiliates thereof) to enter into Interest Rate Protection
Agreements and Other Hedging Agreements with the Borrower and/or the Account
Party; and

            WHEREAS, subject to the terms and conditions set forth below, the
parties hereto wish to amend the Holdings Guaranty as provided herein;

            NOW, THEREFORE, it is agreed;

A.    Amendments

            1. Section 3.01 of the Holdings Guaranty is hereby amended by
inserting the following new clause (s) immediately following clause (r) thereof:

            "(r) Expenditures. As soon as available and in any event within 21
      days after the end of each fiscal month of Holdings, commencing with the
      fiscal month ending February 28, 2003, a schedule of all "Specified
      Expenditures" made in such fiscal month."





            2. Section 3.13(b) of the Holdings Guaranty is hereby amended by
deleting the text "No later than 60 days" appearing therein and inserting the
text "As promptly as possible but no later than 90 days" in lieu thereof.

            3. Section 3.14 of the Holdings Guaranty is hereby amended by
deleting the text "No later than 60 days" appearing therein and inserting the
text "As promptly as possible but no later than 90 days" in lieu thereof.

            4. Section 3.15 of the Holdings Guaranty is hereby amended by
deleting the text "No later than 60 days" appearing therein and inserting the
text "As promptly as possible but no later than 90 days" in lieu thereof.

            5. Section 3.16 of the Holdings Guaranty is hereby amended by
deleting the text "No later than 60 days" appearing therein and inserting the
text "As promptly as possible but no later than 90 days" in lieu thereof.

            6. Section 3.18 of the Holdings Guaranty is hereby amended by
deleting the text "No later than 60 days" appearing therein and inserting the
text "As promptly as possible but no later than 90 days" in lieu thereof.

            7. Section 4.01(b) of the Holdings Guaranty is hereby amended by
inserting the text ", other than errors and omissions coverage incidental to
policies issued to certain financial institutions in accordance with Holdings
and its Subsidiaries underwriting practices as in effect as of the Fourth
Amendment Effective Date" at the end of subclause (iii) thereof.

            8. Section 4.04(d) of the Holdings Guaranty is hereby amended by
deleting the text "and" appearing immediately prior to the reference "(B)"
thereof and inserting the text "or" in lieu thereof.

            9. Section 4.02(a) of the Holdings Guaranty is hereby amended by
inserting the text "(t) the Subsidiaries set forth on Annex IX to the Seventh
Amendment may be liquidated," immediately preceding clause (w) appearing in the
proviso thereof.

            10. Section 4.15 of the Holdings Guaranty is hereby amended to read
in its entirety as follow:

            4.15 Minimum Combined Statutory Surplus. Holdings will not permit
      the Regulated Insurance Companies, collectively, on a Combined basis, to
      have Statutory Surplus (i) at any time prior to the sale of Trenwick
      International Limited, of less than $275,000,000 and (ii) at any time
      after the sale of Trenwick International Limited, of less than
      $250,000,000.

            11. Section 4.16 of the Holdings Guaranty is hereby amended by
deleting the number "$350,000,000" appearing therein and inserting the number
"$250,000,000" in lieu thereof.

            12. Section 4.23 of the Holdings Guaranty is hereby amended to read
its entirety as follows:


                                      -2-



            "4.23 Salary Increases. Holdings will not, and will not permit any
      of its Subsidiaries to, increase the salaries of, or grant bonuses, stock
      options and other forms of compensation to, its employees, officers and/or
      directors, except pursuant to (i) plans in existence on the Fourth
      Amendment Effective Date and in the normal course of business, (ii) the
      Specified Employment Agreements, (iii) the Tier II and Tier III Retention
      Bonus Agreements and the (iv) Unallocated Additional Fee Agreements,
      provided that the payments of any bonus or compensation other than salary
      or monthly fees under the Specified Employment Agreements and the
      Unallocated Additional Fee Agreements may only be made if (I) no Default
      or Event of Default then exists at the time of such payment or would
      result therefrom and (II) if any Default or Event of Default has occurred
      the Required Banks have consented to permit such payments after such
      Default or Event of Default has been cured or waived or (B) the Banks
      consent to such payments notwithstanding that an Event of Default has
      occurred and is continuing."

            13. The definition of "Specified Expenditures" appearing in Schedule
I to the Holdings Guaranty is hereby amended by (i) deleting the text "Credit
Agreement" appearing therein and inserting the text "Credit Documents" in lieu
thereof and (ii) deleting the word "and" appearing immediately before clause
(xvi) thereof and inserting a comma in lieu thereof and inserting the following
new clauses (xvii), (xviii), (xix) and (xx) immediately after the end of clause
(xvi) thereof:

      ", (xvii) reasonable fees and expenses of the holders of the Trenwick
      Senior Notes incurred in connection with the restructuring thereof,
      (xviii) expenditures for reinsurance premium cessions, deposit premiums,
      imprest account funding, commissions, bonus commissions and brokerage
      fees, return premium, losses and loss adjustment expenses, commutation
      payments, claim loss fund accounts, (xix) regulatory fees, 401(k)
      contributions, pension contributions, payroll, CAT modeling license fees,
      software licensing fees, financial printing costs, legal fees for
      reinsurance recovery and claims, accounting, actuarial and tax services
      not related to the restructuring of Holdings and its subsidiaries, systems
      development and maintenance fees, insurance and reinsurance premiums,
      disaster recovery fees, insurance dispute resolution requirements,
      insurance premiums for director's and officer's policies and errors and
      omissions policies and rating agency fees and (xx) other expenses incurred
      in the ordinary course of business, so long as (A) Holdings has notified
      each Bank in writing no later than 5 Business Days before Holdings or the
      applicable Subsidiary makes such expenditure, which notice shall specify
      (w) the entity that will make such payment, (x) the amount of the payment,
      (y) a description of the expenditure and (z) the date such payment will be
      made and (B) the Required Banks do not object to Holdings' or the
      applicable Subsidiary's making such payment prior to the date specified in
      the notice previously delivered pursuant to this clause (xix)."


                                      -3-



            14. Schedule I to the Credit Agreement is hereby amended by
inserting the following defined terms in the appropriate alphabetical order:

            "Binet Employment Agreement" shall mean the letter agreement between
      Holdings and Stephen Binet, dated December 20, 2002, to be amended in
      substantially the form of the draft delivered to the Banks on February 19,
      2003; provided that such Amendment shall also include (i) a
      non-solicitation clause on terms reasonably satisfactory to the
      Administrative Agent and (ii) a provision for the payment of additional
      compensation to Mr. Binet, in the amount set forth on the Senior Executive
      Compensation Schedule, payable on substantially the same terms and
      conditions set forth in the Senior Executive Compensation Schedule and in
      the Executive Compensation Provisions.

            "Becker Agreement" shall mean the letter agreement between Holdings
      and W. Marston Becker, dated August 26, 2002, as amended by the First
      Amendment thereto, dated as of December 31, 2002; provided that such
      letter agreement shall be further amended to include (i) a
      non-solicitation clause on terms reasonably satisfactory to the
      Administrative Agent and (ii) a retention bonus and other additional
      compensation payable to Mr. Becker in the amounts set forth on the Senior
      Executive Compensation Schedule, payable on substantially the same terms
      and conditions set forth in the Senior Executive Compensation Schedule and
      in the Executive Compensation Provisions.

            "Executive Compensation Provisions" shall mean the Executive
      Compensation Provisions, dated March 6, 2003 and delivered to the Banks on
      March 6, 2003.

            "Finkelstein Agreement" shall mean the letter agreement to be
      executed between Holdings and David Finkelstein on terms and conditions
      satisfactory to the Administrative Agent; provided that such letter
      agreement shall include (i) a non-solicitation clause on terms reasonably
      satisfactory to the Administrative Agent and (ii) a retention bonus and
      other additional compensation payable to Mr. Finkelstein in the amounts
      set forth on the Senior Executive Compensation Schedule, payable on
      substantially the same terms and conditions set forth in the Senior
      Executive Compensation Schedule and in the Executive Compensation
      Provisions.

            "Giambo Employment Agreement" shall mean the letter agreement
      between Holdings and Robert Giambo, dated December 17, 2002.

            "Giordano Employment Agreement" shall mean (i) the expatriate
      agreement between Holdings and James A. Giordano, (ii) the change of
      control agreement between Holdings and James A. Giordano and (iii) the
      cash incentive bonus agreement between Holdings and James A. Giordano, in
      each case, which agreements shall be substantially in the form of the
      drafts delivered to the Banks on February 19, 2003, provided that such
      agreements shall also include (i) a non-solicitation clause on terms
      reasonably satisfactory to the Administrative Agent


                                      -4-



      and (ii) a provision for the payment of addition compensation to Mr.
      Giordano, in the amount set forth on the Senior Executive Compensation
      Schedule, payable on substantially the same terms and conditions set forth
      in the Senior Executive Compensation Schedule and in the Executive
      Compensation Provisions.

            "Graham Agreement" shall mean the letter agreement to be executed
      between Holdings and Timothy Graham, on terms and conditions satisfactory
      to the Administrative Agent; provided such letter agreement shall include
      (i) a non-solicitation clause on terms reasonably satisfactory to the
      Administrative Agent and (ii) the payment of additional compensation to
      Mr. Graham in the amount set forth on the Senior Executive Compensation
      Schedule, payable on substantially the same terms and conditions set forth
      in Senior Executive Compensation Schedule and in the Executive
      Compensation Provisions.

            "Hunte Employment Agreement" shall mean the letter agreement between
      Holdings and Alan L. Hunte, dated December 12, 2002, to be amended,
      substantially in the form of the draft delivered to the Banks on February
      19, 2003; provided that such First Amendment shall also include (i) a
      non-solicitation clause on terms reasonably satisfactory to the
      Administrative Agent and (ii) the payment of additional compensation to
      Mr. Hunte in the amount set forth on the Senior Executive Compensation
      Schedule, payable on substantially the same terms and conditions set forth
      in the Senior Executive Compensation Schedule referred to herein and in
      the Executive Compensation Provisions.

            "Semeraro Agreement" shall mean the letter agreement to be executed
      between Holdings and David Semeraro, on terms and conditions satisfactory
      to the Administrative Agent; provided that such letter agreement shall
      include (i) a non-solicitation clause on terms reasonably satisfactory to
      the Administrative Agent and (ii) the payment of additional compensation
      to Mr. Semeraro in the amount set forth on the Senior Executive
      Compensation Schedule, payable on substantially the same terms and
      conditions set forth in the Senior Executive Compensation Schedule and in
      the Executive Compensation Provisions.

            "Senior Executive Compensation Schedule" shall mean the schedule of
      Senior Executive Compensation dated March 6, 2003 and delivered to the
      Banks on March 6, 2003.

            "Seventh Amendment" shall mean the Seventh Amendment to the Holdings
      Guaranty, dated as of March 3, 2003.

            "Seventh Amendment Effective Date" shall have the meaning provided
      in the Seventh Amendment.

            "Specified Employees" shall mean the employees or independent
      contractors of Holdings or its subsidiaries party to the Specified
      Employment Agreements.


                                      -5-



            "Specified Employment Agreements" shall mean collectively, (i) the
      Becker Agreement, (ii) the Binet Employment Agreement, (iii) the
      Finkelstein Agreement, (iv) the Giambo Employment Agreement, (v) the
      Giordano Employment Agreement, (vi) the Graham Agreement (vii) the Hunte
      Employment Agreement, (viii) the Semeraro Agreement and (ix) the Watson
      Employment Agreement.

            "Tier II and Tier III Retention Bonus Agreements" shall mean the
      retention fee agreements executed by Holdings or any Subsidiary thereof
      and any employee or independent contractor of Holdings and/or any
      Subsidiary thereof (other than the Specified Employees) on substantially
      the same terms and conditions as set forth in the Form of Stay Bonus &
      Employment Termination Agreement delivered to the Banks on March 6, 2003
      and in the amounts for each person as set forth on the schedule of
      Executive Compensation dated March 6, 2003 and delivered to the Banks on
      March 6, 2003

            "Unallocated Additional Fee Agreements" shall mean the agreements
      between Holdings and any employee or independent contractor of Holdings
      and/or its Subsidiaries (other than the Specified Employees) to be
      executed on terms and conditions satisfactory to the Administrative Agent;
      provided that such agreements may include a provision for additional
      compensation in an aggregate amount that does not exceed the "Unallocated
      Pool Amount" on the Senior Executive Compensation Schedule.

            "Watson Employment Agreement" shall mean (i) the amended and
      restated service agreement between Trenwick Managing Services Limited,
      Holdings and Michael C. Watson and (ii) the cash incentive bonus agreement
      between Holdings and Michael C. Watson, in each case, which agreements
      will be substantially in the form of the drafts delivered to the Banks on
      February 19, 2003, provided that such agreements will also include (i) a
      non-solicitation clause on terms reasonably satisfactory to the
      Administrative Agent and (ii) the payment of additional compensation to
      Mr. Watson in the amount set forth on the Senior Executive Compensation
      Schedule, payable on substantially the same terms and conditions set forth
      in the Senior Executive Compensation Schedule and in the Executive
      Compensation Provisions.

            15. The Holdings Guaranty is hereby further amended by inserting new
Annex IX attached hereto.

B.    Miscellaneous Provisions

            1. In order to induce the Banks to enter into this Amendment,
Holdings hereby represents and warrants that (i) the representations and
warranties of Holdings contained in the Holdings Guaranty are true and correct
in all material respects on and as of the Seventh Amendment Effective Date (as
defined below) (except with respect to any representations and warranties
limited by their terms to a specific date, which shall be true and correct in
all material respects as of such date), and (ii) there exists no Default or
Event of Default under the Credit


                                      -6-



Agreement on the Seventh Amendment Effective Date (as defined below), in each
case after giving effect to this Seventh Amendment.

            2. This Seventh Amendment is limited as specified and shall not
constitute an amendment, modification, acceptance or waiver of any other
provision of the Holdings Guaranty or any other Credit Document.

            3. THIS SEVENTH AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW
OF THE STATE OF NEW YORK.

            4. This Seventh Amendment shall become effective on the date (the
"Seventh Amendment Effective Date") when (i) Holdings and the Required Banks
shall have signed a counterpart hereof (whether the same or different
counterparts) and shall have delivered (including by way of telecopier) the same
to the Administrative Agent and (ii) the Borrower, the Account Party and the
Required Banks have consented to the Seventh Amendment and Waiver to the Credit
Agreement, dated as of March 7, 2003.

            5. From and after the Seventh Amendment Effective Date, all
references in the Holdings Guaranty and in the other Credit Documents shall be
deemed to be referenced to the Holdings Guaranty as modified hereby.

                                      * * *


                                      -7-



            IN WITNESS WHEREOF, the undersigned have caused this Seventh
Amendment to be duly executed and delivered as of the date first above written.

                                        TRENWICK GROUP LTD.


                                        By: /s/ Alan L. Hunte
                                            ------------------------------
                                            Name:  Alan L. Hunte
                                            Title: Chief Financial Officer





                  [Bank Signature Pages Intentionally Omitted]





                                                                        ANNEX IX

                      CERTAIN SUBSIDIARIES TO BE LIQUIDATED

1.    Castle Members Agents Limited

2.    Target Insurance Company (Guernsey) Limited

3.    Castle Underwriting Holdings Limited

4.    Surveyors Direct Limited

5.    Archer Dedicated Limited

6.    Adit Holdings Limited

7.    Archer Group Services Ltd.

8.    AKC Holdings Ltd.

9.    RL Glover & Co. Underwriting Agents Limited

10.   Halford Motor Insurance Services Limited

11.   Theorem Holdings Limited

12.   Tower Underwriting Agents Limited

13.   Bowman Loss Adjusters Ltd.