Alan L. Hunte, Vice President, Chief Financial Officer and Treasurer,
               Trenwick Group Inc., (NASDAQ National Market: TREN)
                                 (203) 353-5500

            Steven J. Bensinger, President, Chartwell Re Corporation
                 (NYSE: CWL) (203) 705-2520; 011-44-171-369-3000


    TRENWICK GROUP INC. TO ACQUIRE CHARTWELL RE CORPORATION THROUGH A MERGER


     Stamford Connecticut, June 22, 1999 . . .

     Trenwick  Group  Inc.   ("Trenwick")   and  Chartwell  Re  Corporation
     ("Chartwell")  announced today that they have signed a definitive agreement
     for Trenwick to acquire Chartwell.  James F. Billett,  Jr. will continue as
     Chairman, President and Chief Executive Officer of Trenwick, and Richard E.
     Cole,  Chartwell's Chairman and Chief Executive Officer, will join Trenwick
     as  Vice  Chairman  and a  member  of its  Board  of  Directors.  Three  of
     Chartwell's independent directors will be invited to join Trenwick's Board.

     Under the terms of the merger agreement, shareholders of Chartwell will
     receive  0.825  Trenwick  shares  for each  Chartwell  share in a  tax-free
     transaction.  Based on  Trenwick's  closing  price of  $28.88  per share on
     Monday,  June 21, each Chartwell  share would be valued at $23.82,  and the
     total  consideration  for the  acquisition,  including  the  assumption  of
     Chartwell's   debt  and  the  planned  purchase  by  Chartwell  of  reserve
     protection,  would be approximately $368 million.  The equity consideration
     plus the cost of the reserve protection is approximately equal to 0.9 times
     Chartwell's book value at March 31, 1999.

     The  transaction  is subject to the approval of the  respective  companies'
     shareholders,  expiration  of  the  applicable  waiting  period  under  the
     Hart-Scott-Rodino  Antitrust  Improvements  Act,  regulatory  approvals and
     other customary closing conditions.

     On a combined basis, the new Trenwick would have had assets in excess of $3
     billion, shareholders' equity of $517 million and total capitalization of
     $806 million as of March 31, 1999. Based on current  projections,  combined
     gross written  premiums for 1999 are expected to approximate  $891 million.
     At closing,  the  combination  of Trenwick and Chartwell will result in the
     second largest  independent  reinsurer in the U.S., as measured by surplus.
     The company  would have placed  within the top ten domestic  reinsurers  as
     ranked by surplus on the  Reinsurance  Association  of America's  March 31,
     1999 report.

     The companies believe that the transaction  provides a cost-effective means
     of augmenting  capital,  accelerating  premium growth and adding structural
     platforms  for  further   expansion.   The  addition  of  Chartwell's  U.S.
     reinsurance   business,   its  admitted  and  non-admitted  U.S.  insurance
     companies and its operations at Lloyd's continues

     Trenwick's  strategy of entering  new markets and product  lines that began
     with  Trenwick's  acquisition of Trenwick  International  (formerly  Sorema
     U.K.) in 1998.  Trenwick expects that  consolidating the two companies will
     generate  substantial  economies and financial  benefits and will produce a
     transaction that will be immediately accretive to Trenwick's  shareholders.
     The  combination  is  expected  to produce  $15  million and $25 million in
     expense savings in 2000 and 2001, respectively.

     As part of the transaction, Chartwell will purchase $100 million in reserve
     protection.  The  coverage  will  apply  to  all of  Chartwell's  business,
     including its operations at Lloyd's,  underwritten  prior to closing.  This
     reinsurance insulates the future results of the combined companies from any
     unanticipated problems which may arise from Chartwell's past operations.

     Trenwick  Group Inc.  is a holding  company  with two  principal  operating
     subsidiaries,  Trenwick  America Re, which provides  treaty and facultative
     reinsurance  to  insurers  of  property  and  casualty  risks in the United
     States,   and  Trenwick   International,   which  underwrites   treaty  and
     facultative  reinsurance  as well as  specialty  insurance  on a  worldwide
     basis.  Trenwick America Re is rated A+ (Superior) by A.M. Best Company and
     is  assigned a  claims-paying  ability  rating of A+ by  Standard & Poor's.
     Trenwick  International is rated A (Excellent) by A.M. Best Company and has
     also been  assigned  a  claims-paying  ability  rating of A+ by  Standard &
     Poor's.

     Chartwell is an insurance  holding  company  with global  underwriting  and
     service operations, conducting its business in the United States and in the
     Lloyd's market through its principal operating subsidiaries, Chartwell
     Reinsurance Company, INSCORP and Chartwell Managing Agents Limited ("CMA").
     Chartwell   Reinsurance  Company  underwrites  treaty  reinsurance  through
     reinsurance brokers for casualty and, to a lesser extent, property risks as
     well as for marine and aviation risks. INSCORP writes property and casualty
     insurance through specialty program  administrators.  Chartwell Reinsurance
     Company  and  INSCORP  are  rated  A   (Excellent)   and  A-   (Excellent),
     respectively,  by A.M.  Best Company and are  assigned an A-  claims-paying
     ability rating by Standard & Poor's.  CMA manages seven Lloyd's  syndicates
     with a total  underwriting  capacity for 1999 of  approximately  (pound)300
     million ($500 million).  All of CMA's  syndicates  enjoy the benefit of the
     ratings of Lloyd's, which is rated "A" (Excellent) by A.M. Best Company and
     has an A+ claims-paying ability rating from Standard & Poor's.

     Donaldson, Lufkin & Jenrette Securities Corporation acted as financial
     advisor to Trenwick for the transaction  and Goldman,  Sachs & Co. acted as
     financial  advisor to Chartwell.

                                      * * *
     This press release contains forward looking statements of management's
     beliefs,   estimates,   projections   and  assumptions  for  the  financial
     condition,  results of operations  business and prospects of Trenwick after
     the  transaction,  including  anticipated  cost savings and  potential  for
     premium  growth and  business  expansion  that will result.  These  forward
     looking statements involve certain risks and uncertainties, including those
     detailed  from  time to time in  Trenwick's  and  Chartwell's  reports  and
     filings with the Securities  and Exchange  Commission.  Additional  factors
     that may cause actual results to differ materially from those  contemplated
     by such forward looking  statements  include,  among others,  that expected
     cost savings may not be fully realized within the  anticipated  time frame,
     that difficulties  related to the integration of the businesses of Trenwick
     and Chartwell are greater than expected or that expectations for growth may
     not be realizable.



     June 22, 1999