Exhibit 10.14.13
 
           FOURTH AMENDMENT TO SHORT TERM REVOLVING CREDIT AGREEMENT
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          THIS FOURTH AMENDMENT TO REVOLVING CREDIT AGREEMENT, dated as of
December 4, 1998 (this "Amendment"), by and among X.L. Insurance Company, Ltd.
and X.L. Mid Ocean Reinsurance Company, Ltd. (successor to X.L. Global
Reinsurance Company, Ltd.) (the "Borrowers"), X.L. Insurance Company, Ltd. and
EXEL Acquisition Ltd. (the "Guarantors"), MELLON BANK, N.A., (the "Agent") and
the banks listed on the signature pages hereto (collectively, the "Banks").

                              W I T N E S S E T H:
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          WHEREAS, the Borrowers, the Guarantors, the Banks, and the Agent are
parties to a Revolving Credit Agreement, dated as of June 6, 1997, (as amended
by the First Amendment thereto, dated as of November 5, 1997, the Second
Amendment thereto, dated as of May 13, 1998, and the Third Amendment thereto,
dated as of August 3, 1998, the "Credit Agreement"), pursuant to which the Banks
have agreed, on the terms and subject to the conditions described therein, to
make Loans to the Borrowers; and

          WHEREAS, the Borrowers have requested the Banks to make certain
changes to the Credit Agreement; and

          WHEREAS, the Banks are willing to amend the Credit Agreement as set
forth below; and

          WHEREAS, capitalized terms used herein and not otherwise defined shall
have the meanings assigned to them in the Credit Agreement;

          NOW THEREFORE, in consideration of the premises and of the mutual
covenants herein contained, and intending to be legally bound hereby, the
parties hereto agree as follows:

          SECTION 1.  AMENDMENTS TO CREDIT AGREEMENT.  The Credit Agreement is
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hereby amended as follows:

          (a) Section 2.04(c) of the Credit Agreement is hereby amended by
deleting the words "One, two, three, six or twelve months ('Euro-Rate Funding
Period')" appearing under the column heading "Available Funding Periods"
                                              -------------------------
appearing therein and inserting in lieu of such words under such column heading
the following: "One, two, three, six or twelve months or, if acceptable to all
Banks, one or two weeks ('Euro-Rate Funding Period')".

 
          (b)  Section 6.03(e) of the Credit Agreement is hereby amended to read
as follows:

                 (e)  Liens securing Indebtedness permitted by Section 6.08(b)
               or Section 6.08(c) hereof covering assets whose market value is
               not materially greater than an amount equal to the amount of the
               Indebtedness secured thereby, plus a commercially reasonable
               margin.

          (c)  Section 6.08(b) of the Credit Agreement is hereby amended by
deleting the word "Unsecured" appearing at the beginning thereof.


          SECTION 2.  EFFECT OF AMENDMENT.  The Credit Agreement, as amended by
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this Amendment, is in all respects ratified, approved and confirmed and shall,
as so amended, remains in full force and effect.


          SECTION 3.  GOVERNING LAW.  This Amendment shall be deemed to be a
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contract under the laws of the Commonwealth of Pennsylvania and for all purposes
shall be governed by and construed and enforced in accordance with the laws of
said Commonwealth.


          SECTION 4.  COUNTERPARTS.  This Amendment may be executed in any
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number of counterparts and by the different parties hereto on separate
counterparts, each of which, when so executed, shall be deemed an original, but
all such counterparts shall constitute but one and the same instrument.



          IN WITNESS WHEREOF, the parties hereto have executed this Amendment as
of the date first above written.

                                          X.L. INSURANCE COMPANY, LTD.
                                          as a Borrower and as a Guarantor
                           
                           
                                          By:_________________________________
                                          Title:______________________________

                                      -2-

              
                                       X.L. MID OCEAN REINSURANCE COMPANY, 
                                         LTD. (successor to X.L. Global 
                                         Reinsurance Company, Ltd.),
                                         as a Borrower
              
                                       By:_________________________________
                                       Title:______________________________
              
              
              
                                       EXEL ACQUISITION LTD.,
                                         as a Guarantor
              
              
                                       By:_________________________________
                                       Title:______________________________
              
              
              
                                       MELLON BANK, N.A., as a Bank
                                         and as Agent
              
              
                                       By:_________________________________
                                       Title:______________________________
              
              
              
                                       BANK OF TOKYO - MITSUBISHI LTD.,
                                         as a Bank
              
              
                                       By:_________________________________
                                       Title:______________________________
              
              
                                       DEUTSCHE BANK AG, NEW YORK OR CAYMAN 
                                         ISLANDS BRANCHES,
                                         as a Bank
              
                                       By:_________________________________
                                       Title:______________________________
              
              
              
                                       By:_________________________________
                                       Title:______________________________
              
              
              
                                       THE BANK OF NOVA SCOTIA,
                                         as a Bank
              
              
                                       By:_________________________________
                                       Title:______________________________

                                      -3-

 
                                            THE CHASE MANHATTAN BANK,
                                                as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            THE BANK OF BERMUDA LIMITED,
                                                as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            ROYAL BANK OF CANADA,
                                                as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            BANQUE NATIONALE DE PARIS,
                                                as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            BANK OF AMERICA NT&SA,
                                                as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            CREDIT LYONNAIS NEW YORK BRANCH,
                                              as a Bank
                  
                  
                                            By:_________________________________
                                            Title:______________________________
                  
                  
                  
                                            By:_________________________________

                                      -4-

               
                                            Title:______________________________
            
              
                                            BANK AUSTRIA AKTIENGESELLSCHAFT,
                                            as a Bank
            
            
                                            By:_________________________________
                                            Title:______________________________
            
            
              
                                            By:_________________________________
                                            Title:______________________________
            
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