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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 10-K

(Mark One)
[X]  ANNUAL REPORT  PURSUANT TO SECTION 13 OR 15(d) OF THE  SECURITIES  EXCHANGE
     ACT OF 1934 [FEE REQUIRED]

     For the fiscal year ended December 31, 1999.

                                       OR

[ ]  TRANSITION  REPORT  PURSUANT  TO  SECTION  13 OR  15(d)  OF THE  SECURITIES
     EXCHANGE ACT OF 1934 [NO FEE REQUIRED]

     For the transition period _______________ to _______________.

                         Commission file number 1-15389

                               TRENWICK GROUP INC.
             (Exact name of registrant as specified in its charter)

           Delaware                                            06-1152790
(State or other jurisdiction of                              (I.R.S. Employer
incorporation or organization)                              Identification No.)

                One Canterbury Green, Stamford, Connecticut 06901
               (Address of principal executive offices)  (Zip Code)

       Registrant's telephone number, including area code: (203) 353-5500

           Securities registered pursuant to Section 12(b) of the Act:

                                                 Name of Each Exchange
         Title of Each Class                     on Which Registered
Common Stock, par value $.10 per share          New York Stock Exchange
     Preferred Stock Purchase Rights            New York Stock Exchange

        Securities registered pursuant to Section 12(g) of the Act: None

     Indicate  by check mark  whether the  registrant  (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.
Yes  |X| No |_|

     Indicate by check mark if disclosure of delinquent  filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's  knowledge,  in definitive proxy or information  statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. |_|

     The  aggregate  market  value on March 24, 2000 of the voting stock held by
non-affiliates of the registrant was $224,696,190.

     The number of shares  outstanding of each of the issuer's classes of common
stock as of the close of the period covered by this report:

             Class                                Outstanding at March 24, 2000
             -----                                -----------------------------
Common Stock, $.10 par value                               16,295,207

Certain portions of the registrant's  definitive proxy statement relating to its
annual  meeting  of  stockholders  scheduled  to be  held on May  18,  2000  are
incorporated  by reference into Part III of this report and certain  portions of
the  registrant's  annual report to stockholders  are  incorporated by reference
into Parts II and IV of this report.

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                               TRENWICK GROUP INC.

                                Table of Contents



                                                                                                         Page
Item                                                                                                    Number
- - ----                                                                                                    ------
                                     PART I
                                                                                                       
 1.  Business  .........................................................................................   1
 2.  Properties  .......................................................................................  22
 3.  Legal Proceedings  ................................................................................  23
 4.  Submission of Matters to a Vote of Security Holders  ..............................................  23

                                   PART II

 5.  Market for the Corporation's Common Stock and Related Stockholder Matters  ........................  24
 6.  Selected Financial Data  ..........................................................................  25
 7.  Management's Discussion and Analysis of Financial Condition and
     Results of Operation  .............................................................................  27
 7a. Quantitative and Qualitative Disclosures About Market Risk.........................................  27
 8.  Financial Statements and Supplementary Data  ......................................................  27
 9.  Changes in and Disagreements with Accountants on Accounting and
     Financial Disclosure  .............................................................................  27

                                  PART III

10.  Directors and Executive Officers  .................................................................  27
11.  Executive Compensation  ...........................................................................  28
12.  Security Ownership of Certain Beneficial Owners and Management  ...................................  28
13.  Certain Relationships and Related Transactions  ...................................................  28

                                   PART IV

14.  Exhibits, Financial Statement Schedules and Reports on Form 8-K  ..................................  28






                                     PART I

Item 1. Business

General Background and History

Trenwick  Group  Inc.   ("Trenwick")  is  a  specialty  insurance   underwriting
organization with multiple  distribution  platforms in insurance and reinsurance
operating  through its subsidiaries  located in the United States and the United
Kingdom.   Trenwick's  four  principal  operating  units  are  Trenwick  America
Reinsurance   Corporation   ("Trenwick   America  Re"),  which  provides  treaty
reinsurance  to insurers of property  and casualty  risks in the United  States;
Trenwick  International  Limited ("Trenwick  International"),  which underwrites
treaty and facultative reinsurance as well as specialty insurance on a worldwide
basis;   Chartwell  Managing  Agents  Limited  ("Chartwell   Managing  Agents"),
Trenwick's  managing  agency at Lloyd's;  and  Canterbury  Financial  Group Inc.
("Canterbury Financial"), which underwrites U.S. property and casualty insurance
through specialty program administrators.

Trenwick was incorporated in the State of Delaware in 1985. Trenwick America Re,
a  Connecticut  corporation,  operated  as  a  subsidiary  of  Trenwick  America
Corporation  from 1983  through  1985 and was  acquired by Trenwick in 1985 as a
result of a corporate restructuring. Trenwick acquired Trenwick International in
February 1998 and  Chartwell Re  Corporation  ("Chartwell")  in October 1999. In
connection  with the  acquisition  of  Chartwell,  Trenwick  acquired  Chartwell
Managing Agents, Chartwell Reinsurance Company ("Chartwell Reinsurance"),  whose
reinsurance  business  was  assumed by Trenwick  America  Re, and The  Insurance
Corporation  of New York  ("INSCORP")  and Dakota  Specialty  Insurance  Company
("Dakota"),  both of which are operating companies for Canterbury Financial.  In
addition, Trenwick owns several inactive Bermuda subsidiaries.

On December 19, 1999,  Trenwick  announced that it had entered into a definitive
agreement to combine with LaSalle Re Holdings Limited, with shareholders of each
company to receive shares in a new Bermuda  holding company to be named Trenwick
Group Ltd. This transaction is expected to be completed in the second quarter of
2000.

Each of  Trenwick's  operating  insurance  company  subsidiaries  is  rated  "A"
(Excellent) by A.M. Best Company and has been assigned an A+ financial  strength
rating by Standard & Poor's.  All of Chartwell Managing Agents' 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.
These  ratings  are  based  upon  factors  that may be of  concern  to policy or
contract  holders,   agents  and   intermediaries,   but  may  not  reflect  the
considerations  applicable to an equity investment in a reinsurance or insurance
company.  A change in any such  rating is at the  discretion  of the  respective
rating agencies.





Trenwick's  gross and net  premium  writings  for its  operational  units are as
follows:

                                            1999           1998           1997
                                          --------       --------       --------
Gross Premiums Written

     Trenwick America Re                  $210,921(1)    $218,249       $248,662
     Trenwick International                171,698        105,114(2)          --
     Chartwell Managing Agents              84,834(3)          --             --
     Canterbury Financial                   38,088(4)          --             --
                                          --------       --------       --------
     Total                                $505,541       $323,363       $248,662
                                          ========       ========       ========

Net Premiums Written

     Trenwick America Re                  $155,108(1)    $169,112       $195,230
     Trenwick International                129,399         81,107(2)          --
     Chartwell Managing Agents              64,462(3)          --             --
     Canterbury Financial                    5,641(4)          --             --
                                          --------       --------       --------
     Total                                $354,610       $250,219       $195,230
                                          ========       ========       ========

(1)  Includes reinsurance business of Chartwell Reinsurance and its subsidiaries
     since its acquisition on October 27, 1999.

(2)  Includes Trenwick  International business since its acquisition on February
     27, 1998.

(3)  Includes  Chartwell  Managing  Agents  business  since its  acquisition  on
     October 27, 1999.

(4)  Includes Canterbury Financial business since its acquisition on October 27,
     1999.

Trenwick America Reinsurance Corporation

Trenwick  America Re,  which  comprised  44% of  Trenwick's  total net  premiums
written in 1999,  underwrites United States treaty  reinsurance,  which accounts
for the  majority  of its  business,  as well as a small  amount of  facultative
reinsurance.  In this section,  Trenwick  America Re's 1999 results  include the
reinsurance  business of Chartwell  Reinsurance and its  subsidiaries  since its
acquisition on October 27, 1999.

Trenwick  America Re generally  obtains all of its business  through brokers and
reinsurance  intermediaries  which seek its  participation on reinsurance  being
placed for their  customers.  In underwriting  reinsurance,  Trenwick America Re
does not target types of clients,  classes of business or types of  reinsurance.
Rather,  it selects  transactions  based upon the quality of the reinsured,  the
attractiveness of the reinsured's  insurance rates and policy conditions and the
adequacy of the proposed reinsurance terms.

Trenwick America Re's commitment is currently limited to $2,500,000 per contract
on  casualty  treaty  business  and  $1,500,000  on  property  business.  Larger
commitments are subject to Trenwick's Underwriting Committee referral process.


                                       2



Trenwick  America Re's net premiums written by line of business are set forth in
the following table for the periods indicated.

                    Trenwick America Reinsurance Corporation
                    Net Premiums Written By Lines of Business
                                 (in thousands)

                                             1999(1)        1998         1997
                                            ---------    ---------    ---------
Casualty

         Automobile Liability               $  17,831    $  51,299    $  50,187
         Errors and Omissions                  45,557       36,655       40,063
         General Liability                     22,170       17,743       20,795
         Accident and Health                   17,922       11,014        6,326
         Medical Malpractice                    3,422        7,700       10,293
         Workers' Compensation                  8,297        3,025       18,328
         Products Liability                     1,834        2,312        1,743
         Other Casualty                        12,431        2,697        9,133
                                            ---------    ---------    ---------
                  Total Casualty              129,464      132,445      156,868
                                            ---------    ---------    ---------
Property                                       25,644       36,667       38,362
                                            ---------    ---------    ---------
         Total                              $ 155,108    $ 169,112    $ 195,230
                                            =========    =========    =========

(1)  Includes reinsurance business of Chartwell Reinsurance and its subsidiaries
     since its acquisition on October 27, 1999.

The major lines of  reinsurance  currently  written by  Trenwick  America Re are
automobile liability,  errors and omissions,  general liability and accident and
health. Together these lines account for an aggregate of at least 67% of its net
premiums  written in all years  indicated.  The overall  decline in net premiums
written  since 1997 is a result of three  principal  causes.  Competition  among
primary  companies  has caused  cedants to reduce their own premium  writings or
restructure their reinsurance programs,  reducing the amount of reinsurance they
purchase.  As a  result  of  consolidation  within  the  industry,  many  ceding
companies are now larger and financially stronger,  enabling them to retain more
risk. In addition,  increasingly  intense competition in the reinsurance markets
has driven reinsurance prices on a number of accounts below pricing levels which
Trenwick  America Re will accept.  The 65% decline in  automobile  liability net
premium  writings  in 1999  resulted  from the  non-renewal  of two  significant
accounts,  one of which was commuted in the fourth quarter of 1999. Accident and
health net  premiums  written  increased  by 63% compared to 1998 as a result of
Trenwick  America Re's strategic  alliance with Duncanson and Holt. This account
was  non-renewed  in 2000 following the sale of Duncanson and Holt. In 1999, the
amount of property business,  including automobile physical damage, underwritten
by Trenwick  America Re remained  constant as a percentage  of total net written
premiums.

Three ceding companies accounted for approximately 25%, 38%, and 32% of Trenwick
America Re's gross premiums written in 1999, 1998 and 1997, respectively. During
1999,  Duncanson  and  Holt,  American  International  Group  and CNA  Insurance
Companies accounted for 11%, 7% and 7%,  respectively,  of Trenwick America Re's
gross  premiums  written.  While  Trenwick  America Re believes that the loss of
these  accounts  will not have a material  adverse  effect on the  business  and
operations of Trenwick,  Trenwick does not believe that such a loss would have a
long-term adverse effect because of Trenwick's



                                       3



competitive  position  within the  reinsurance  market and the  availability  of
business from other brokers and ceding  companies.  Further,  Trenwick  believes
that it will continue to underwrite new business to replace the accounts.

Trenwick International Limited

Trenwick  International's  business, which accounted for 36% of Trenwick's total
net premiums written in 1999, consists  principally of insurance and facultative
reinsurance  of  specialty  classes.  Trenwick  International  also  underwrites
property and casualty treaty  reinsurance.  In the latter part of 1998, Trenwick
International  opened a branch office in Paris which  specializes in facultative
reinsurance of large,  technically  complex property risks.  Premiums written by
the Paris branch in 1999 were not material.

Trenwick  International  also  obtains  all of  its  business  through  brokers.
Trenwick  International's  business  consists of  Specialist  Risk  Underwriting
("SRU") which includes  direct  insurance,  facultative  reinsurance  and treaty
reinsurance.  The following table reflects Trenwick International's net premiums
written by type of business for 1999 and 1998.

             International Net Premiums Written By Type of Business

                             (dollars in thousands)

                        1999                        1998
                  -----------------          -----------------
SRU                 98,926      76%           83,397       83%
Treaty              30,473      24%           17,385       17%
                  -----------------          -----------------
Total             $129,399     100%          100,782      100%
                  =================          =================

Specialist Risk Underwriting

SRU underwrites  business in both London and Paris.  Trenwick's branch office in
Paris  was  opened  in  September  of 1998.  The  principal  lines  of  business
underwritten in 1999 and 1998 include property, engineering, accident and health
professional indemnity, financial institutions, liability, extended warranty and
yacht hull. In 1999,  approximately 53% of Trenwick International's net premiums
were written directly as insurance.

Trenwick's  Paris  branch  specializes  in large,  complex  property  risks that
require  a  high  degree  of  underwriting  expertise.   Trenwick  International
generally   underwrites  this  business,   which  includes  large  manufacturing
facilities,  construction  projects as well as both onshore and offshore  energy
risks, as facultative reinsurance, but can also function directly as an insurer.
The Paris branch benefits from a pool of  underwriters  trained as engineers and
has emerged as a center for this type of technical underwriting.

Treaty

Trenwick  International's  treaty business includes  liability  business,  which
accounted for  approximately 51% of treaty business in 1999, as well as property
and  credit   business.   Treaty  is  written   both  on  a   proportional   and
non-proportional basis.



                                       4



Chartwell Managing Agents

Trenwick  participates in the Lloyd's market through Chartwell  Managing Agents,
which is a managing agent at Lloyd's and through four Lloyd's corporate members.
Chartwell Managing Agents receives fees and profit commissions in respect of the
underwriting and administrative services it provides to the Lloyd's underwriting
syndicates  that it manages.  For the 2000 year of account,  Chartwell  Managing
Agents  manages  three  syndicates  with  a  total   underwriting   capacity  of
approximately  $377.1 million. In 1998 and 1999,  Chartwell Managing Agents sold
to third parties the rights to manage  syndicates 866 (motor),  947 (non-marine)
and 994  (non-marine)  and combined into a single syndicate for the 2000 year of
account the remaining  non-life  syndicates.  Trenwick  retains the benefits and
obligations with respect to its Lloyd's corporate member participation interests
in those syndicates for the open years of account at the time of the sale.

Trenwick's  Lloyd's corporate members  participated on three Lloyd's  syndicates
for the 2000 year of account,  providing an aggregate  of  approximately  $350.1
million of capacity to those syndicates. Approximately 93% of Chartwell Managing
Agents syndicates' 2000 year of account capacity was supplied by Trenwick.

Classes of business  covered by Chartwell  Managing Agents'  syndicates  include
marine, non-marine property, non-marine liability, motor, aviation and life. The
table set forth below shows the gross premiums  written for  Trenwick's  Lloyd's
corporate members for the periods indicated.  All amounts in the table below are
presented in  accordance  with U.S.  generally  accepted  accounting  principles
("GAAP").

                      Trenwick's Lloyd's Corporate Members
                Gross Premiums Written by Lloyd's Market Segment
                            (dollars in thousands)(1)

                                            Year Ended December 31,
                             ---------------------------------------------------
                                       1999                        1998
                             ------------------------    -----------------------
                              Amount       % of Total     Amount      % of Total
                             --------      ----------    --------     ----------
Motor                        $ 37,370        17.7%       $ 36,212        49.9%
Non-Marine                    140,337        66.5          31,121        42.9
Aviation                       19,802         9.4           3,194         4.4
Marine                         12,350         5.9           1,757         2.4
Life                            1,092          .5             289         0.4
                             --------       -----        --------       -----
Total                        $210,951       100.0%       $ 72,573       100.0%
                             ========       =====        ========       =====

(1)Business at Lloyd's is conducted in pounds sterling. The dollar amounts shown
here have been converted from pounds  sterling at the average  exchange rate for
each of the years presented.  Data shown for 1998 and that portion of 1999 prior
to October 27, 1999 is not included in Trenwick's  financial  statements because
Trenwick  acquired  Chartwell  Managing Agents and its related Lloyd's corporate
members on October 27, 1999.

Canterbury Financial Group

Canterbury   Financial  Group  develops  insurance  programs  through  specialty
production sources with a focus on a specific line or lines of business,  with a
limited geographic emphasis, and where the program administrator's  compensation
is  adjusted  based on the  underwriting  results  of the  business.  Canterbury
Financial Group evaluates each business relationship based upon the underwriting
experience  and  operational  expertise  of the  production  source.  Canterbury
Financial  Group  periodically  performs  underwriting,  claims and  operational
audits of each of its production sources.

Canterbury  Financial  Group's gross written premiums grew 32.7%, 4.3% and 81.3%
for the years ended  December 31, 1999,  1998 and 1997,  respectively,  over the
prior year. The increases in premium reflect the



                                       5



geographic  expansion  of existing  programs as well as the  development  of new
programs during the periods shown.

The table set forth  below  shows the  gross  premiums  written  for  Canterbury
Financial Group for the periods indicated:

                           Canterbury Financial Group
                   Gross Premiums Written by Line of Business
                            (dollars in thousands)(1)



                                                              Year Ended December 31,
                                  ----------------------------------------------------------------------------------
                                          1999                         1998                         1997
                                  ---------------------         ---------------------         ----------------------
                                   Amount         Total          Amount         Total          Amount         Total
                                  --------        -----         --------        -----         --------        ------
                                                                                            
Commercial Multiple Peril         $ 41,909         28.4%        $ 45,737         41.2%        $ 48,404         45.4%
General Liability                   36,743         25.0           31,575         28.4           30,418         28.6
Automobile                          46,471         31.5           23,354         21.0           22,267         20.9
Workers Compensation                12,589          8.5            4,224          3.8            4,169          3.9
Homeowners and Other                 9,786          6.6            6,241          5.6            1,285          1.2
                                  --------        -----         --------        -----         --------        -----
Total                             $147,498        100.0%        $111,131        100.0%        $106,543        100.0%
                                  ========        =====         ========        =====         ========        =====


(1) Data shown for 1998 and that  portion of 1999 prior to October  27,  1999 is
not  included in  Trenwick's  financial  statements  because  Trenwick  acquired
Canterbury Financial on October 27, 1999.

During the year ended December 31, 1999,  Canterbury  Financial Group underwrote
approximately  64% of its gross premiums  through three managing general agents,
of which Florida Intracoastal  Underwriters accounted for approximately 31%, HDR
Insurance Services accounted for approximately 22% and Inter-Reco  accounted for
approximately  11%. No other managing  general agent accounted for more than 10%
of  Canterbury  Financial  Group's  gross  insurance  premiums  written for such
period.

In order to reduce the potential  adverse effect arising from the termination of
any specific business relationship, Canterbury Financial Group continues to seek
to establish and develop  relationships  with a large number of managing general
agents.  While  management  believes  that its  relationships  with its managing
general agents are satisfactory,  the termination of all or a substantial number
of these  relationships could have a material adverse effect on the business and
operations of Canterbury Financial Group.

Marketing

Trenwick  generally  obtains its  business  through  insurance  and  reinsurance
brokers which represent the ceding company and clients in  negotiations  for the
purchase  of  insurance  or  reinsurance.  The  process of  effecting a brokered
placement  typically begins when a client or ceding company enlists the aid of a
broker in  structuring an insurance or  reinsurance  program.  Often the various
parties will consult  with one or more lead  underwriters  as to the pricing and
contract terms of the protection being sought. Once the terms quoted by the lead
underwriter have been approved, the broker will offer participation to qualified
insurers or reinsurers  until the program is fully subscribed at terms agreed to
by all parties.

Trenwick pays such intermediaries or brokers commissions representing negotiated
percentages  of the  premium it writes.  These  commissions  constitute  part of
Trenwick's total acquisition costs and are included



                                       6



in its underwriting expenses. Brokers do not have the authority to bind Trenwick
America Re with respect to  agreements.  Under  certain  limited  circumstances,
selected  administrators  have the  authority  to bind  Trenwick  International,
Chartwell  Managing  Agents  and  Canterbury  Financial  Group  business.  These
administrators  are  subject to  periodic  financial  and  operational  reviews.
Trenwick  does not commit in advance to accept any portion of the business  that
brokers  submit to it.  Business  from any company,  whether new or renewal,  is
subject to acceptance by Trenwick.

During 1999, three reinsurance  brokers,  AON Reinsurance  Agency, Guy Carpenter
and E. W. Blanch  generated 37%, 16% and 8%,  respectively,  of Trenwick America
Re's gross written premiums.  These brokers are among the ten largest brokers in
the insurance and reinsurance industry.  Loss of all or a substantial portion of
the business provided by Trenwick's brokers could have a material adverse effect
on the business and operations of Trenwick.  Trenwick does not believe, however,
that the loss of such business would have a long-term  adverse effect because of
Trenwick's  competitive  position  within the broker  insurance and  reinsurance
market and the availability of business from other brokers.

Underwriting

Trenwick's  underwriting  philosophy  emphasizes  a  transactional  approach  to
underwriting  in which any insurance or reinsurance  transaction for any line of
property or casualty business is considered on its own merits. The underwriter's
primary  objective is to assess the potential for an  underwriting  profit.  The
risk  assessment  process  undertaken  by  Trenwick's  underwriters  involves  a
comprehensive  analysis of historical  data,  when  available,  and estimates of
future value of loss costs which may not be evident in the historical  data. The
factors  which  Trenwick  considers  include  the type of risk,  details  of the
underlying  insurance  coverage  provided,  adequacy of pricing using  actuarial
analysis and the terms and conditions.  With respect to its domestic  operations
which comprises fewer but  significantly  larger accounts,  Trenwick  frequently
conducts  underwriting  and claims  audits of ceding  companies  to assist it in
evaluating the information submitted by the ceding companies, before agreeing to
participate in a reinsurance transaction.

Trenwick has established formal  underwriting policy standards for both domestic
and  international  operations.  This process  involves  pre-binding  reviews of
individual material transactions by its senior underwriting staff.  Underwriting
policies  for  insurance  and  reinsurance   transactions  are  supplemented  by
conducting  periodic internal audits of each  underwriting  department to ensure
compliance with underwriting policies and procedures.

Competition

Trenwick competes with numerous major  international and domestic  insurance and
reinsurance  companies.  These  competitors,  many of which  have  substantially
greater  financial  and  staff  resources  than  Trenwick,  include  independent
insurance and reinsurance  companies,  subsidiaries or affiliates of established
insurance  companies,  reinsurance  departments of certain commercial  insurance
companies and underwriting syndicates.

Competition in the types of business which Trenwick underwrites is based on many
factors.  These factors include the perceived overall financial  strength of the
insurer or reinsurer, rates charged, other terms and conditions,  agency ratings
(including A.M. Best Company and Standard & Poor's),  service offered,  speed of
service   (including  claims  payment)  and  perceived   technical  ability  and
experience  of  staff.  The  number  of  jurisdictions  in which an  insurer  or
reinsurer is licensed or authorized to do business is also a factor.



                                       7



The  financial  security of insurers and  reinsurers  has emerged as a key issue
throughout the 1990's.  To be accepted by clients,  and by ceding  companies and
their  brokers,  insurers  and  reinsurers  must  demonstrate  higher  levels of
financial security and solvency than were previously required. Transactions tend
to  have  fewer  and  larger  participants,  which  may  negatively  affect  the
availability of underwriting opportunities for Trenwick.

Trenwick's  management  believes that the insurance  and  reinsurance  industry,
including the broker market, will continue to undergo further  consolidation and
that size and  financial  strength will  continue to be  significant  factors in
effective competition.

Claims Administration

Claims   are   managed   by   Trenwick's   professional   claims   staff   whose
responsibilities  include the review of initial loss reports,  creation of claim
files, determination of whether further investigation is required, establishment
and adjustment of case reserves and payment of claims.  In addition,  the claims
staff conducts  comprehensive  claims audits of both specific claims and overall
claims  procedures at the offices of selected brokers and ceding  companies.  In
certain instances, a claims audit may be performed prior to assuming reinsurance
business as part of a  comprehensive  risk  evaluation  process.  For  insurance
business, Trenwick's claim staff uses their own judgement as well as advice from
lawyers and loss adjusters where appropriate.

In  connection  with  the  acquisition  of  Chartwell,   Trenwick   acquired  an
environmental  claims unit to evaluate the complex  toxic tort and latent injury
claims resident in one of Chartwell's subsidiaries, The Insurance Corporation of
New York.

Unpaid Claims and Claims Expenses

General

Insurers  and  reinsurers   establish   claims  and  claims   expense   reserves
representing  estimates  of future  amounts  needed to pay  claims  and  related
expenses with respect to insured events which have  occurred.  Claims and claims
expense  reserves have two  components:  case  reserves,  which are reserves for
reported  claims,  and incurred but not reported  ("IBNR")  reserves,  which are
reserves  for claims not yet  reported.  Significant  periods of time may elapse
between the occurrence of an insured  claim,  the reporting of the claims to the
insurer  and the  subsequent  reporting  of the  claims  to the  reinsurer,  the
insurer's payment of that claim, and later payments by the reinsurer.

Trenwick  first  establishes  its case  reserves  for  reported  claims  when it
receives notice of the claim. It is Trenwick's policy to establish  reserves for
reported claims in an amount equal to the greater of the reserve  recommended by
the ceding  company or the claim as estimated by  Trenwick's  claims  personnel.
Trenwick  periodically  conducts  investigations  to  determine  if  the  amount
reserved by the ceding company is appropriate or should be adjusted.  During the
claim  settlement  period,  which may be many years,  additional facts regarding
individual  claims may become known. As Trenwick learns additional facts, it may
become



                                       8



necessary to refine and adjust  upward or downward the  estimated  reserves on a
claim,  and even then the  ultimate net reserve may be less than or greater than
the revised  estimates.  Trenwick  does not  discount  any of its  reserves  for
reported  or  unreported  claims  in any line of its  business  for  anticipated
investment income.

Actuarial Methods

Trenwick  utilizes  the two most common  methods of  actuarial  evaluation  used
within the  insurance  industry,  the  Bornhuetter-Ferguson  method and the loss
development method. The Bornhuetter-Ferguson  method involves the application of
selected loss ratios to  Trenwick's  earned  premiums to determine  estimates of
ultimate expected loss and loss adjustment  expenses for each underwriting year.
Multiplying  expected losses by  underwriting  year by a selected loss reporting
pattern gives an estimate of reported and unreported IBNR losses.  When the IBNR
is added to the loss and loss adjustment  expense amounts with respect to claims
that have been  reported to date, an estimated  ultimate  expected loss results.
This method  provides a more stable estimate of IBNR that is insulated from wide
variations  in  reported  losses.  In  contrast,  the  loss  development  method
extrapolates the current value of reported losses to ultimate expected losses by
using selected  reporting  patterns of losses over time. The selected  reporting
patterns are based on historical  information  (organized into loss  development
triangles) and are adjusted to reflect the changing  characteristics of the book
of business written by Trenwick.

Trenwick  provides capital to its Lloyd's corporate  members,  which support the
underwriting  capacity of the Lloyd's  syndicates  managed by Chartwell Managing
Agents. Loss reserves for this business are established using methods similar to
those  used  by  Trenwick  for its  operating  insurance  company  subsidiaries.
Chartwell  Managing  Agents has engaged Bacon & Woodrow  London Market  Services
Ltd.  ("B&W"),  an  independent  actuarial  consulting  firm, to review the loss
reserves and prepare an actuarial opinion for each of its syndicates,  including
the  actuarial  opinion  required  by  Lloyd's  solvency  regulations.  The  B&W
opinions,  which are prepared  solely for the use of Lloyd's  regulators and are
only to be relied upon by Chartwell  Managing  Agents,  assist its syndicates in
establishing appropriate reserve estimates for both the reinsurance to close and
the open years of account.

In the reserve setting process,  Trenwick includes  provisions for inflation and
"social inflation" if appropriate,  as losses are generally not determined until
some time in the future.  Trenwick continually monitors legislative activity and
evaluates  the  potential  effect  of any  legislative  changes  on its  reserve
liabilities.

Trenwick's  reserves  are  carried at the full  amount  estimated  for  ultimate
expected losses and loss adjustment  expense without any discount to reflect the
time value of money in accordance with both statutory  accounting  practices and
GAAP.  Trenwick's  actuarial department regularly performs loss reserve analyses
for its operating insurance company subsidiaries.


                                       9



Reserve Analysis

The following table presents the development of Trenwick's net unpaid claims and
claims  expenses for 1989 through 1999.  The top line of the table shows the net
unpaid  claims and claims  expenses  at the  balance  sheet date for each of the
indicated  years.  This reflects the net estimated  amounts of claims and claims
expenses for claims  arising in that year and in all prior years that are unpaid
at the balance sheet date,  including  claims that had been incurred but not yet
reported to Trenwick.  The upper  portion of the table shows the net  cumulative
subsequently paid amounts as of successive years with respect to that liability.
The  middle  portion  of the  table  shows  the net  re-estimated  amount of the
previously recorded net unpaid claims and claims expenses based on experience as
of the end of each  succeeding  year. The estimates  change as more  information
becomes known about the frequency and severity of claims for individual years. A
redundancy  (deficiency)  exists  when the net  re-estimated  liability  at each
December 31 is less  (greater)  than the prior net liability  estimate.  The net
"Cumulative  Redundancy  (Deficiency)"  depicted in the table for any particular
calendar year represents the aggregate  change in the initial net estimates over
all subsequent calendar years.

The lower  portion  of the table  presents  a  reconciliation  of the net unpaid
claims  and claims  expenses  as of the end of the year with the  related  gross
unpaid  claims and  claims  expenses  as of  December  31,  1991  through  1999.
Additionally,  the table  presents a  reconciliation  of the gross  re-estimated
unpaid  claims and  claims  expenses  as of the end of the latest  re-estimation
year,  with  separate  disclosure  of  the  related   re-estimated   reinsurance
recoverable  on  unpaid  claims  and  claims  expenses.  The  "gross  cumulative
redundancy"  depicted  in the table for the  calendar  years 1991  through  1999
represents  the  aggregate  change  in the  initial  gross  estimates  over  all
subsequent calendar years.


                                       10



                DEVELOPMENT OF UNPAID CLAIMS AND CLAIMS EXPENSES

                                 (in thousands)



- - ----------------------------------------------------------------------------------------------------------------------------------
                                           1999       1998        1997       1996        1995       1994       1993        1992
- - ----------------------------------------------------------------------------------------------------------------------------------
                                                                                                  
Net unpaid claims and claims
expenses, end of year                   $1,207,436    $449,264  $ 379,351    $386,887   $327,001    $294,008   $268,091   $266,685

Cumulative amount of net
liability paid as of:
         One year later                                172,674    104,718      94,197     46,860      61,804     52,300     52,260
         Two years later                                          194,188     162,565    110,289      81,417     90,382     93,312
         Three years later                                             --     215,803    149,810     121,133     89,445    118,345
         Four years later                                              --          --    178,919     142,485    112,119    111,174
         Five years later                                              --          --         --     156,204    124,096    125,847
         Six years later                                               --          --         --          --    134,535    133,502
         Seven years later                                             --          --         --          --         --    139,779
         Eight years later                                             --          --         --          --         --         --
         Nine years later                                              --          --         --          --         --         --
         Ten years later                                               --          --         --          --         --         --

Net liability re-estimated as of:

         One year later                                463,892    372,176     381,521    322,562     291,943    267,644    255,379
         Two years later                                          383,584     374,336    317,199     279,561    263,473    255,379
         Three years later                                                    381,463    308,700     274,283    246,367    252,458
         Four years later                                              --          --    309,282     265,041    241,478    236,009
         Five years later                                              --          --         --     266,583    229,742    230,488
         Six years later                                               --          --         --          --    230,824    222,094
         Seven years later                                             --          --         --          --         --    223,473
         Eight years later                                             --          --         --          --         --         --
         Nine years later                                              --          --         --          --         --         --
         Ten years later                                               --          --         --          --         --         --



Net cumulative redundancy (deficiency)                 (14,628)    (4,233)       5,424     17,719       27,425     37,267     43,212
Percentage                                                           (1)%          1%         5%           9%        14%       16%
Gross Liability, end of year                           682,428    518,387     467,177    411,874     389,298    354,582    351,897
Reinsurance recoverable                                233,164    139,036      80,290     84,873      95,290     86,491     85,212
Net liability, end of year                             449,264    379,351     386,887    327,001     294,008    268,091    266,685
Gross re-estimated liability-latest                    719,143    521,011     462,384    393,765     339,514    293,613    288,355
Re-estimated recoverable-latest                        255,251    137,427      80,921     84,483      72,931     62,789     64,882
Net re-estimated liability-latest                      463,892    383,584     381,463    309,282     266,583    230,824    223,473
Gross cumulative redundancy (deficiency)               (36,715)    (2,624)      4,793     18,109      49,784     60,969     63,542



- - --------------------------------------------------------------------------
                                          1991        1990       1989
- - --------------------------------------------------------------------------
                                                        
Net unpaid claims and claims
expenses, end of year                     $258,774   $245,105    $214,391

Cumulative amount of net
liability paid as of:
         One year later                     44,930     42,234      29,407
         Two years later                    80,725     77,183      60,888
         Three years later                 111,225    102,590      84,283
         Four years later                  127,431    124,129     101,597
         Five years later                  116,224    134,657     116,047
         Six years later                   127,130    122,089     124,465
         Seven years later                 132,194    129,100     110,656
         Eight years later                 137,401    132,888     115,017
         Nine years later                       --    136,959     117,364
         Ten years later                        --         --     120,895

Net liability re-estimated as of:

         One year later                    253,781    238,324     206,724
         Two years later                   243,488    233,565     199,864
         Three years later                 243,586    223,417     196,232
         Four years later                  241,600    224,171     188,052
         Five years later                  225,592    223,172     189,148
         Six years later                   217,852    213,327     188,884
         Seven years later                 208,701    205,179     180,619
         Eight years later                 211,487    199,948     176,778
         Nine years later                       --    202,578     172,846
         Ten years later                        --         --     175,362



Net cumulative redundancy (deficiency)      47,287     42,527      39,029
Percentage                                     18%        17%         18%
Gross Liability, end of year               332,503
Reinsurance recoverable                     73,729
Net liability, end of year                 258,774
Gross re-estimated liability-latest        268,217
Re-estimated recoverable-latest             56,730
Net re-estimated liability-latest          211,487
Gross cumulative redundancy (deficiency)    64,286




                                       11




In evaluating the  information in the table on the preceding  page, it should be
noted that each amount  includes the effects of all changes in amounts for prior
periods.  For example,  if a claim  determined  in 1991 to be $150,000 was first
reserved  in 1986 at  $100,000,  the  $50,000  deficiency  (actual  claim  minus
original  estimate)  would  be  included  in  the  gross  cumulative  redundancy
(deficiency)  in each of the years  1986-1991  shown on the preceding page. This
table does not present accident or policy year development data.  Conditions and
trends that have  affected  the  development  of  liability  in the past may not
necessarily  occur in the  future.  Accordingly,  it may not be  appropriate  to
extrapolate future redundancies or deficiencies based on this table.

The trend  depicted  in the table  indicates  that net unpaid  claims and claims
expense  liability at December 31, 1998 and 1997 have developed  unfavorably due
to  Trenwick  America  Re's  unfavorable  development  for claims  occurring  in
accident  years 1996 through 1998.  For further  discussion of unpaid claims and
claims expenses, see Note 4 of Notes to the Consolidated Financial Statements of
Trenwick.

Management believes that Trenwick's reserves are adequate.  However, the process
of  estimating  reserves is  inherently  imprecise and involves an evaluation of
many  variables,   including  potentially   unpredictable  social  and  economic
conditions.  Accordingly,  there can be no assurance  that  Trenwick's  ultimate
liability  will not vary  significantly  from  amounts  reserved.  The  inherent
uncertainties  of estimating  such reserves are greater for reinsurers  than for
primary  insurers,  primarily  due to the  longer-term  reporting  nature of the
reinsurance  business,  the diversity of development  patterns  among  different
types of reinsurance, the necessary reliance on ceding companies for information
regarding  reported  claims  and  differing  reserving  practices  among  ceding
companies.  Reserves  also include  provisions  for latent  injury or toxic tort
claims that cannot be estimated with traditional  reserving  techniques.  Due to
inconsistent  court  decisions in federal and state  jurisdictions  and the wide
variation  among  insureds  with  respect  to  underlying  facts  and  coverage,
uncertainty  exists with  respect to these  claims as to  liabilities  of ceding
companies and,  consequently,  reinsurance  coverage.  Management  believes that
Trenwick's  exposure to such latent losses is lessened because of its relatively
recent  entry  into the  reinsurance  business  (other  than  INSCORP),  its low
historical  levels of premium volume prior to the  application of exclusions for
asbestos and  environmental  liabilities,  its  retrocessional  programs and the
protection  afforded by Trenwick's  Contingent  Interest Notes due June 30, 2006
(the  "Contingent  Interest Notes") the payment of which is subject to reduction
in the event of such adverse reserve development related to INSCORP's business.

Reserves for Trenwick's  participation in Lloyd's syndicates through its Lloyd's
corporate  members  are  included  in the 1999  year end  reserves.  Part of the
reserve  represents  reinsurance to close balances  brought  forward to the open
years of  account  (for  example,  1996  reinsured  into the  1997  open  year).
Favorable or unfavorable  development of the prior year's reserves can influence
the results of the open years of 1997, 1998 and 1999. Consequently, there can be
no assurance as to the adequacy of reserves and the risk of future developments,
both favorable and unfavorable, exists.


                                       12



Trenwick's  reserves  include an estimate of Trenwick's  ultimate  liability for
asbestos and  environmental  claims.  The gross and net unpaid claims and claims
expenses for asbestos and environmental claims are as follows:



                                                              1999          1998        1997
- - ------------------------------------------------------------------------------------------------
(in thousands)
                                                                              
Unpaid claims and claims expenses gross of
     reinsurance recoverable, end of year                   $ 100,131      $ 8,476     $  8,924
Unpaid claims and claims expenses, net of
     reinsurance recoverable, end of year                      72,092        8,428        8,814
Reinsurance recoverable on unpaid claims and
     claims expenses, end of year                              28,039           48          110


The increase of the gross and net unpaid claims and claims expenses  reflect the
inclusion of the reserves related to the Chartwell acquisition. Under Trenwick's
current  interpretation of policy language,  management does not believe that it
has a  material  exposure  to  environmental  claims  that  requires  additional
reserves beyond its current estimates.

Contingent Interest Notes

Upon  consummation  of the  acquisition  of Chartwell,  Trenwick  assumed all of
Chartwell's   obligations  under  the  Contingent  Interest  Notes,  which  were
originally issued by Piedmont  Management  Company Inc. to its stockholders just
prior to its  acquisition by Chartwell in 1995. The Contingent  Interest  Notes,
which mature on June 30, 2006, are designed to provide  Trenwick with protection
against adverse development of INSCORP's reserves for losses and loss adjustment
expenses.  In the  event  there  is no  adverse  development,  Trenwick  will be
required  to pay the  holders  of the CI  Notes  approximately  $55  million  in
contingent  interest.  This contingent interest payment is in addition to the $1
million  principal amount of the Contingent  Interest Notes and interest on such
principal  amount at 8% per  annum  (collectively,  the  "Fixed  Amount")  which
Trenwick  in any  event  must  pay at  maturity  or  earlier  redemption  of the
Contingent Interest Notes.

In general,  assuming the Contingent Interest Notes are settled at maturity, the
contingent interest will be equal to $55 million (a) less an amount equal to (i)
the amount of any adverse  development of the loss and loss  adjustment  expense
reserves  and  related  accounts  (including  certain  reinsurance  recoverable,
commissions  and unearned  premiums)  of INSCORP  recorded as of March 31, 1995,
minus (ii) $25 million,  (b) plus the amount of certain tax benefits received or
recorded by Trenwick as a result of the amount determined pursuant to clause (a)
above.  The amount so  calculated  may not be greater  than $55 million nor less
than a minimum  amount  equal to the  lesser of (a) $10  million  less the Fixed
Amount  and (b) the tax  benefits  referred  to  above.  In the  event  that the
Contingent  Interest Notes are settled prior to maturity,  the foregoing formula
will in  general  apply,  except  that the $55  million  maximum  amount  of the
Contingent  Interest  Notes will be reduced  to an amount  equal to $55  million
discounted  back  from  June  30,  2006  at a  discount  rate  of 8% per  annum,
compounded  annually,  and the tax benefits  will be  calculated in a prescribed
manner.

The carrying value of the Contingent  Interest Notes on Trenwick's  consolidated
financial  statements at December 31, 1999 was $34.7 million,  representing  the
sum of the aggregate  principal amount of the Contingent  Interest Notes and the
present  value as of such  date of the  maximum  amount of  contingent  interest
payable on the  Contingent  Interest  Notes at their  stated  maturity  in 2006.
During the term of the Contingent  Interest Notes, the discounted carrying value
of the Contingent  Interest Notes will be increased to reflect  accretion of (i)
interest on the principal amount and (ii) the discounted contingent interest. To
the



                                       13



extent that adverse  development of INSCORP's reserves (including IBNR reserves)
occurs prior to the maturity or redemption of the Contingent Interest Notes, the
contingent  interest payable on the Contingent  Interest Notes (and,  therefore,
the  then-current  carrying  value of such  Contingent  Interest  Notes) will be
reduced.  Such reductions in the carrying value of the Contingent Interest Notes
would offset in part,  in the period in which such adverse  development  occurs,
any reduction in Trenwick's GAAP net income and  stockholders'  equity resulting
from such adverse reserve development (that would,  however,  still be reflected
in Trenwick's statutory  underwriting results and in the policyholders'  surplus
of INSCORP and any parent insurer of INSCORP).

At its option,  Trenwick may settle the Contingent Interest Notes with shares of
common stock of Trenwick  instead of payment of cash. For purposes of settlement
of the Contingent  Interest  Notes,  such common stock would be valued at 85% of
its average closing market price over a specified period prior to the settlement
date.  However,  Trenwick may not settle the  Contingent  Interest  Notes in its
common stock unless (i) such stock is  registered  under the  Securities  Act of
1933 (or is  otherwise  freely  tradeable  other than by certain  affiliates  of
Trenwick),  (ii) such stock is listed on a national  securities  exchange or the
NASDAQ  National  Market and (iii) all Contingent  Interest Notes are settled in
such common stock.  Moreover,  Trenwick may not settle the  Contingent  Interest
Notes in its common stock if the  Contingent  Interest  Notes are being  settled
following  acceleration  thereof due to an event of default under the Contingent
Interest Notes.

Reinsurance and Retrocessional Agreements

Trenwick enters into reinsurance and retrocessional agreements to reduce its net
liability on individual risks,  protect against catastrophic losses and maintain
acceptable ratios.

Trenwick America Re has various retrocessional facilities, all of which are on a
treaty basis.  These  retrocessional  facilities include one treaty for Trenwick
America Re's facultative casualty reinsurance business,  which applies on a risk
or account basis,  and two for its treaty  property  business,  which protect it
against multiple claims arising out of a single occurrence or event. As a result
of these facilities,  Trenwick America Re's maximum retention generally does not
exceed  $500,000 per  occurrence  on  facultative  business and  $2,300,000  per
occurrence on property catastrophe business. From 1989 to 1999, Trenwick America
Re  has  purchased  aggregated  excess  of  loss  ratio  treaties  from  several
reinsurers.  These  facilities  provided  Trenwick  with a layer  of  protection
against  adverse  results  from its  domestic  casualty  business  in  excess of
specified  loss ratios.  Trenwick  did not purchase an aggregate  excess of loss
ratio treaty for 2000.

Trenwick  International,  as customary  with  companies  operating in the London
market,  buys  large  amounts of  reinsurance.  Reinsurance  and  retrocessional
coverage is  customized  for each class of business.  During 1998,  following an
increase in its share capital, Trenwick International increased its retention of
business by reducing the amount of reinsurance it buys, principally proportional
reinsurance treaties with its former parent.

Chartwell  Managing Agency, as part of its business  strategy,  has historically
purchased a  significant  amount of  reinsurance  for the Lloyd's  syndicates it
manages.  Reinsurance is generally  purchased to protect the syndicates  against
extraordinary  loss or loss  involving  one or more  underwriting  classes.  The
amount  purchased is  determined  with  reference to the  syndicates'  aggregate
exposure and potential loss scenarios.

Canterbury Financial Group purchases  reinsurance  specifically tailored to each
of the specialty programs underwritten by its insurance subsidiaries.



                                       14



In  connection  with the  acquisition  of  Chartwell  by  Trenwick,  Chartwell's
insurance company subsidiaries purchased an aggregate excess of loss reinsurance
agreement  providing  up to  $100  million  in  coverage  against  unanticipated
increases in Chartwell's  reserves for business written on or before October 27,
1999, the date of completion of the  acquisition  of Chartwell.  Within the $100
million  maximum,  the  protection  is limited  to $100  million  for  increased
reserves  attributable  to  Chartwell's  Lloyd's  operations,  $25  million  for
increased  reserves  attributable  to  catastrophe  and year 2000 losses and $50
million  for  increased  reserves  attributable  to asbestos  and  environmental
coverage  losses.  The  aggregate  excess of loss  reinsurance  agreement is not
cancelable  by the  reinsurers,  London  Life  and  Scandanavian  Re  and  their
obligations  have been secured by a trust account.  The premium payable for this
aggregate excess of loss reinsurance agreement was approximately $56 million.

Trenwick  remains liable with respect to insurance and reinsurance  ceded in the
event that the insurer or  retrocessionaire  is unable to meet its  obligations.
All reinsurers and retrocessionaires  must be formally approved by the operating
company's Security Committee.  The Security Committees re-evaluate the financial
condition of Trenwick reinsurers and  retrocessionaires  at least annually.  The
evaluation process involves financial analysis of current audited financial data
and comparative analysis of such data in accordance with guidelines  established
by Trenwick.  Business may not be conducted with  retrocessionaires  who are not
currently approved by the Security Committees.

Trenwick  America  Re's  principal  retrocessionaires  are  Zurich  Reinsurance,
Continental  Casualty  Company,  Unum Life  Insurance  Company  of  America  and
National    Union   Fire   Insurance    Company.    Chartwell   Re's   principal
retrocessionaires  are Centre Reinsurance  (Bermuda) Limited and London Life and
Casualty  Reinsurance  Corp.  and  Scandinavian   Reinsurance  Company  Limited.
INSCORP's  largest  reinsurers  in  1999  were  American   Reinsurance  company,
Navigators  Insurance  Company and European  International  Reinsurance  Company
Limited. Trenwick International has two principal  retrocessionaires,  Lloyds of
London and Transatlantic Re. All these retrocessionaires are rated A (Excellent)
or better by A.M. Best Company.  At December 31, 1999,  Trenwick had no material
uncollectible amounts due from its  retrocessionaires.

Investments

The Investment  Committee of Trenwick's Board of Directors oversees  investments
and sets procedures and guidelines for investment strategy.  Trenwick's internal
staff manage these investments and utilize the services of investment  advisers.
Trenwick's  investment  strategy  focuses  on  capital  preservation  and income
predictability. This strategy also requires that the risks associated with these
objectives are properly managed.  Accordingly,  Trenwick  emphasizes  investment
grade debt investments.  At December 31, 1999, 79% of Trenwick's  investments in
debt securities were rated Aa or better. In October 1998, certain securities had
their ratings  withdrawn by various  nationally  recognized  statistical  rating
organizations. The servicer of these securities,  Commercial Financial Services,
Inc.,  filed for protection  under Chapter 11 of the Federal  Bankruptcy Code in
December 1998. During 1999, Trenwick wrote down the value of these securities by
$5.2 million.

Trenwick's  investment strategy permits an allocation for equity securities.  At
December 31, 1999, 6% of Trenwick's total  investments and cash were invested in
common and preferred  equities,  which consist primarily of securities issued by
U.S. and United Kingdom  corporations.  The primary risk  associated  with these
securities is the exposure to daily market fluctuations.



                                       15



The investments of each of Trenwick's insurance company subsidiaries must comply
with the  respective  insurance  laws of the  jurisdiction  of  domicile of that
insurance  company,  and of the other  jurisdictions  in which it is licensed or
authorized.  These  laws  prescribe  the  kind,  quality  and  concentration  of
investments  which may be made by insurance  companies.  In general,  these laws
permit   investments,   within   specified   limits   and   subject  to  certain
qualifications,  in federal, state and municipal  obligations,  corporate bonds,
preferred and common stock,  real estate  mortgages and real estate.  These laws
generally  penalize  high  concentrations  of  riskier  types of assets and high
exposures to certain types of issuers.

Trenwick  invests  in  three  types  of  structured  securities,  collateralized
mortgage  obligations  ("CMO"),  mortgage-backed  securities  not backed by U.S.
government agencies ("non-agency MBS") and asset-backed securities ("ABS"), each
accounting for 5%, 5% and 2%, respectively,  of Trenwick's portfolio at December
31, 1999.

CMOs  consist  of  planned   amortization   classes  ("PACs")  which  have  been
constructed  with a certain  amount of call  protection  and CMOs that have lost
their PAC protection (sometimes called "broken" or "busted" PACs), due to actual
prepayments being significantly higher or lower than originally forecast.  These
agency  backed CMOs are not subject to credit  risk,  as all holdings are backed
indirectly or directly by the Federal  government  or one of its  agencies.  The
material risk inherent to holding these CMOs is prepayment  risk,  which relates
to  the  timing  of  cash  flows  that  result  from  amortization,  whether  it
accelerated,  because of lower interest rates and therefore higher than expected
prepayments,  or  decelerated,  because of higher  interest  rates and therefore
lower  than  expected   prepayments.   Changes  in  principal  repayments  could
negatively affect investment income due to the timing of the reinvested funds.

Non-agency MBSs are constructed  primarily from the  securitization of mortgages
on commercial or residential  real estate and,  lacking any agency backing,  are
inherently  subject to credit risk. They also have an element of prepayment risk
which  is  contingent  on the  structure  of each  security  and its  underlying
collateral.  93% of the  non-agency  MBS issues  Trenwick has  purchased  have a
rating of A or better from  various  Nationally  Recognized  Statistical  Rating
Organizations.

The  asset-backed  securities  owned by Trenwick have primarily  credit card and
home equity receivables as collateral and are subject also to credit risk. These
securities have less cash flow  uncertainty  than non-agency MBS and CMO issues,
because  the  issuer  has  the  ability  to  add in new  collateral  should  the
asset-backed security experience faster prepayments,  or in the event of default
on the  underlying  collateral.  94% of the  asset-backed  securities  owned  by
Trenwick  are rated A or better by  various  Nationally  Recognized  Statistical
Rating  Organizations.  The  remaining  6% include the  asset-backed  securities
serviced by  Commercial  Financial  Services,  Inc. for which  ratings have been
withdrawn.

Trenwick also invests in agency pass-through  securities which account for 7% of
Trenwick's  portfolio at December 31, 1999. As with CMOs,  these  securities are
subject to prepayment risk.

Trenwick holds debt  securities and cash in a number of currencies.  At December
31, 1999,  approximately 16% of Trenwick's debt securities and cash were held in
U.K. sterling, and the remainder in six other currencies.


                                       16



The table below sets forth the distribution of Trenwick's  investments available
for sale at December 31, 1999 by type, maturity and quality rating.

                                   Investments
                             (dollars in thousands)



                                                                     Average       Estimated
                                                                     Maturity         Fair             Amortized
                                                                     In Years        Value                Cost
                                                                     --------        -----                ----
                                                                                             
Type (debt securities)
U.S. Government bonds                                                  4.3         $  114,537         $  114,839
Obligations of states and political subdivisions(1)                    6.3            454,993            460,176
Mortgage-backed and asset-backed securities                            8.1            288,535            290,801
Debt securities issued by British government                           3.7            115,023            117,165
Debt securities issued by other foreign governments                    4.9             54,996             55,436
Public utilities                                                      14.7             20,891             21,229
Corporate securities                                                   8.3            259,446            262,855
Certificates of deposit                                                 .2              2,940              2,937
                                                                                   ----------         ----------
Total debt securities                                                  6.8         $1,311,361         $1,325,438
                                                                                   ==========         ==========
Maturity (debt securities)
Due in one year or less                                                 .5             94,546             93,913
Due in one year through five years                                     2.9            544,077            545,161
Due after five years through ten years                                 7.3            482,652            490,465
Due after ten years                                                   19.1            190,086            195,899
                                                                                   ----------         ----------
      Total debt securities                                            6.8         $1,311,361         $1,325,438
                                                                                   ==========         ==========
Quality (debt securities)
Aaa(2)-U.S. government bonds                                                       $  114,537         $  114,839
      Obligations of states and political subdivisions                                349,474            352,936
      Mortgage-backed and asset-backed securities                                     211,980            211,775
      Debt securities issued by British government                                    115,023            117,165
      Debt securities issued by other foreign governments                              31,402             31,783
      Corporate securities                                                             14,585             14,959
      Certificates of deposit                                                           1,991              1,988
                                                                                   ----------         ----------
                                                                                      838,992            845,445
                                                                                   ----------         ----------
Aa(2)-Obligations of states and political subdivisions                                 77,762             78,661
      Mortgage-backed and asset-backed securities                                      44,554             45,923
      Corporate securities                                                             58,250             58,558
      Debt securities issued by other foreign governments                              16,707             16,715
      Public utilities                                                                  2,438              2,483
                                                                                   ----------         ----------
                                                                                      199,711            202,340
                                                                                   ----------         ----------
A(2)-Obligations of states and political subdivisions                                  16,006             16,232
      Mortgage-backed and asset-backed securities                                      24,522             25,465
      Debt securities issued by other foreign governments                               6,887              6,938
      Public utilities                                                                 13,065             13,152
      Corporate securities                                                            105,932            106,928
      Certificates of deposit                                                             809                809
                                                                                   ----------         ----------
                                                                                      167,221            169,524
                                                                                   ----------         ----------
Baa(2)-Obligations of states and political subdivisions                                11,751             12,347
      Mortgage-backed and asset-backed securities                                       5,983              6,142
      Public utilities                                                                  4,335              4,469
      Corporate securities                                                             56,631             57,476
                                                                                   ----------         ----------
                                                                                       78,700             80,434
                                                                                   ----------         ----------
Ba(2)-Public utilities                                                                  1,053              1,125
      Corporate securities                                                             12,543             13,032
                                                                                   ----------         ----------
                                                                                       13,596             14,157
                                                                                   ----------         ----------
B(2)-Corporate securities                                                              11,143             11,495
                                                                                   ----------         ----------
Caa(2)-Corporate securities                                                               138                183
                                                                                   ----------         ----------
P1(2)-Certificates of deposits                                                            140                140
                                                                                   ----------         ----------
      Non-rated Corporate security                                                        224                224
                                                                                   ----------         ----------
      Withdrawn - Asset-backed securities                                               1,496              1,496
                                                                                   ==========         ==========
      Total debt securities                                                        $1,311,361         $1,325,438
                                                                                   ----------         ----------



                                       17


(1)   Obligations  of states  and  political  subdivisions  include  $38,240,000
      escrowed in U.S. Government Securities,  $242,320,000 insured by Municipal
      Bond  Investors  Assurance   Corporation,   Financial  Guaranty  Insurance
      Company,  AMBAC Indemnity  Corporation,  or Financial  Security  Assurance
      Corporation and $29,940,000 both escrowed and insured.

(2)   Quality  rating as assigned by Moody's  Investors  Service,  Inc.  for all
      except certain  mortgage-backed  securities not backed by U.S.  government
      agencies and certain  asset-backed  securities.  Quality ratings for these
      other securities are as assigned by Fitch Investors Service,

     Standard and Poor's or Duff and Phelps. Ratings are generally assigned upon
     the issuance of the securities, subject to revision on the basis of ongoing
     evaluations.

                                      18



Regulation

Trenwick  and its  insurance  company  subsidiaries  are  subject to  regulatory
oversight under the insurance  statutes and regulations of the  jurisdictions in
which they conduct  business,  including all states of the United States and the
United Kingdom. These regulations vary from jurisdiction to jurisdiction and are
generally  designed to protect ceding insurance  companies and  policyholders by
regulating   Trenwick's   financial  integrity  and  solvency  in  its  business
transactions  and  operations.  Many of the insurance  statutes and  regulations
applicable to Trenwick's  subsidiaries relate to reporting and enable regulators
to closely monitor  Trenwick's  performance.  Typical  required  reports include
information  concerning  Trenwick's  capital  structure,   ownership,  financial
condition, and general business operations.

Trenwick  International  is subject to the  regulatory  authority  of the United
Kingdom  Financial  Services  Authority.  Both  Chartwell  Managing  Agents  and
Trenwick's  dedicated  Lloyd's  underwriting  entities,  as a  Lloyd's  managing
general  agent and  Lloyd's  corporate  members,  respectively,  are  subject to
regulation and supervision by the Council of Lloyd's.  Lloyd's  operates under a
self-regulatory  regime  under  the  Lloyd's  Act 1982 and has the power to set,
interpret and change the rules which govern the operation of the Lloyd's market,
subject to regulation for solvency purposes by the Financial Services Authority.
Lloyd's  prescribes,  in respect of its managing  agents and corporate  members,
certain minimum standards relating to their management and control, solvency and
various other requirements.  In addition,  Lloyd's imposes  restrictions against
persons  becoming  controllers  and major  shareholders  of managing  agents and
corporate members without the consent of Lloyd's first having been obtained. The
United Kingdom  government has established the Financial Services Authority as a
single  regulator  to  supervise  securities,  banking and  insurance  business,
including  Lloyd's.  When the  Financial  Services  and Market Bill becomes law,
probably  in  late  2000,  the  Financial  Services  Authority  will  have  wide
authorization  and  intervention  powers in relation to Lloyd's.  A consultation
process has commenced in relation to Lloyd's regulatory framework.

NAIC

The National Association of Insurance  Commissioners ("NAIC") is an organization
which  assists  state  insurance  supervisory  officials in achieving  insurance
regulatory  objectives,  including  the  maintenance  and  improvement  of state
regulation.  From time to time various  regulatory and legislative  changes have
been proposed in the insurance  industry,  some of which could have an effect on
reinsurers.  Among the  proposals  that have in the past been or are at  present
being considered are the possible introduction of federal regulation in addition
to, or in lieu of, the  current  system of state  regulation  of  insurers,  and
proposals  in various  state  legislatures  (some of which  proposals  have been
enacted) to conform  portions of their insurance laws and regulations to various
model acts adopted by the NAIC.  Trenwick is unable to predict  what effect,  if
any, these developments may have on its operations and financial condition.  See
Item 7, Management's  Discussion and Analysis of Financial Condition and Results
of Operations.

Risk Based Capital

The NAIC has adopted  Risk-Based  Capital ("RBC")  requirements for property and
casualty  insurance  companies to evaluate the adequacy of statutory capital and
surplus in relation to  investment  and insurance  risks such as asset  quality,
asset and liability matching,  loss reserve adequacy and other business factors.
The RBC formula is used by state  insurance  regulators as an early warning tool
to  identify,  for  the  purpose  of  initiating  regulatory  action,  insurance
companies  that  potentially  are  inadequately  capitalized.  In addition,  the
formula  defines  minimum  capital  standards that  supplement the system of low
fixed  minimum  capital  and surplus  requirements  on a  state-by-state  basis.
Regulatory  compliance is determined by a ratio of the  enterprise's  regulatory
total adjusted  capital to its  authorized  control level RBC, as defined by the
NAIC.  Enterprises below specific trigger points or ratios are classified within
certain levels, each of which



                                       19



requires  specific  corrective  action.  The ratios of Total Adjusted Capital to
Authorized  Control  Level RBC for each of Trenwick's  United  States  insurance
company  subsidiaries  exceeded all the RBC trigger points at December 31, 1999,
1998 and 1997.

State Insurance Regulation

The  premium  rates  and  policy  terms  of  Trenwick's  reinsurance  agreements
generally  are not  subject to  regulation  by any  government  authority.  This
contrasts with Trenwick's  property and casualty insurance  operations where the
premium  rates  and  policy  terms  are  generally  closely  regulated  by state
insurance departments. As a practical matter, however, the premium rates charged
by insurers may place a limit on the rates which can be charged by reinsurers.

The regulation and supervision to which  Trenwick's  insurance  subsidiaries are
subject  relate  primarily  to the  standards  of solvency  that must be met and
maintained, licensing requirements for reinsurers, the nature of and limitations
on investments, restrictions on the size of risks which may be insured, deposits
of securities for the benefit of insureds or reinsureds,  methods of accounting,
periodic examinations of the financial condition and affairs of reinsurers,  the
form and content of reports of  financial  condition  required to be filed,  and
reserves for unearned  premiums,  losses and other  purposes.  In general,  such
regulation  is for the  protection of the insureds and  reinsureds,  rather than
Trenwick's security holders. Trenwick believes that it is in compliance with all
such material regulations.

Trenwick is subject to  regulation  under the  insurance  statutes and insurance
holding company statutes of various states, including Connecticut,  New York and
North Dakota,  the domicile states of its U.S. insurance  companies.  These laws
and  regulations  vary from state to state,  but generally  require an insurance
holding  company,  and  insurers  and  reinsurers  that are  subsidiaries  of an
insurance holding company, to register with the state regulatory authorities and
to file with those authorities certain reports including information  concerning
their capital  structure,  ownership,  financial  condition and general business
operations.

State laws also require prior notice or regulatory  agency approval of direct or
indirect changes in control of an insurer,  reinsurer or its holding company and
of certain  significant  intercorporate  transfers of assets  within the holding
company  structure.   An  investor  who  acquires  securities   representing  or
convertible into more than 10% of the voting power of the securities of Trenwick
would become subject to at least some of such  regulations  and would be subject
to  approval  by  the   Connecticut,   New  York  and  North  Dakota   Insurance
Commissioners  prior to  acquiring  such  shares.  Such  investor  would also be
required to file certain  notices and reports with the  Insurance  Commissioners
prior to such acquisition.

Codification of Statutory Accounting Principles

In March  1998,  the NAIC  adopted  the  Codification  of  Statutory  Accounting
Principles ("Codification").  The Codification, which is intended to standardize
regulatory  accounting and reporting for the insurance industry,  is proposed to
be January 1, 2001. The Codification provides guidance for areas where statutory
accounting  has been silent and changes  current  statutory  accounting  in some
areas. However,  statutory accounting principles will continue to be established
by individual state laws and permitted practices. Effective January 1, 2001, the
states of Connecticut  (domicile of Trenwick America Re), Minnesota (domicile of
Chartwell  Reinsurance),  New York  (domicile  of  INSCORP  and ReCor) and North
Dakota  (domicile of Dakota) will adopt the  Codification.  It is uncertain what
effect adoption of the Codification  for the preparation of statutory  financial
statements would have on those statutory financial statements.



                                       20




Dividends

Because Trenwick's operations are conducted through its operating  subsidiaries,
Trenwick  is  dependent  upon the  ability  of its  operating  subsidiaries,  to
transfer funds,  principally in the form of cash dividends,  tax  reimbursements
and other  statutorily  permissible  payments.  In  addition  to  general  legal
restrictions  on payments of dividends and other  distributions  to shareholders
applicable to all corporations, Trenwick's insurance subsidiaries are subject to
further  regulations that, among other things,  restrict the amount of dividends
and other distributions that may be paid to their parent corporations.

Under the  applicable  provisions of the insurance  holding  company laws of the
states of domicile of Trenwick  America Re,  Chartwell  Reinsurance  and Dakota,
such  companies  may only pay dividends  without the approval of the  applicable
state insurance regulator, if such dividends, together with other dividends paid
within the preceding twelve months,  are less than the greater of (i) 10% of the
insurer's  policyholders'  surplus as of the end of the prior  calendar  year or
(ii) the insurer's  statutory net income,  excluding realized capital gains, for
the  prior  calendar  year.  As a further  restriction,  the  maximum  amount of
dividends  most U.S.  insurers  may pay is limited to its earned  surplus,  also
known as its unassigned  funds. Any dividend in excess of the amount  determined
pursuant to the foregoing  formula would be characterized  as an  "extraordinary
dividend" requiring the prior approval of the state insurance regulator.

Under New York law, which is applicable to INSCORP and ReCor  Insurance  Company
Inc.  ("ReCor") the maximum ordinary dividend payable in any twelve month period
without the approval of the New York  Insurance  Department is the lesser of (i)
10% of policyholders  surplus as shown on the company's last annual statement or
any  more  recent  quarterly  statement  or  (ii)  the  company's  adjusted  net
investment  income.  Adjusted net investment income is defined as net investment
income for the twelve months  preceding the declaration of the dividend plus the
excess, if any, of net investment income over dividends  declared or distributed
during the period  commencing  thirty-six  months  prior to the  declaration  or
distribution of the current dividend and ending twelve months prior thereto.  In
any case, New York law permits the payment of an ordinary dividend by an insurer
or reinsurer only out of earned surplus.

In addition to the foregoing limitations,  the New York Insurance Department, as
is its practice in any change of control situation,  required Trenwick to commit
to preclude the acquired New  York-domiciled  insurers,  INSCORP and ReCor, from
paying any dividends for two years after the merger with Chartwell without prior
regulatory approval.  The foregoing restriction will expire on October 27, 2001.
Neither INSCORP nor ReCor paid any dividends in 1997, 1998 or 1999.

Moreover, insurance holding company laws generally provide that, notwithstanding
the  receipt of any  dividend  from a  subsidiary  insurer,  an insurer may make
dividend  payments  to its parent  only to the extent it is  permitted  to do so
under its applicable  dividend  restrictions.  In other words,  the ability of a
subsidiary  insurer to pay dividends without  restriction may be impaired if its
parent insurer cannot pay dividends without restriction.

The maximum  dividend  permitted  by law may not be  indicative  of an insurer's
actual ability to pay dividends,  which may be constrained by business and other
regulatory  considerations,  such as the impact of dividends  on surplus,  which
could  affect an  insurer's  ratings  or  competitive  position,  the  amount of
premiums  that  can  be  written  and  the  ability  to  pay  future  dividends.
Furthermore,  beyond the limits described in the preceding paragraph,  insurance
regulatory  authorities  often  have the  discretion  to limit  the  payment  of
dividends by insurance companies domiciled in their jurisdictions.

In 2000,  of Trenwick's  U.S.  insurance  subsidiaries,  only Dakota could pay a
dividend  or  other  distribution  without  prior  approval  of  the  applicable
insurance regulatory  authority.  In 2000, Dakota Specialty could pay a dividend
of $2.8 milion  without prior  approval.  During 1999,  1998 and 1997,  Trenwick
America Re paid dividends of $53.4 million, $30.1




                                       21



million and $8.3  million,respectively.  Chartwell Reinsurance paid dividends of
$30.3 million in 1999 and $3.0 million in 1997.  Chartwell  Reinsurance  did not
pay any dividends in 1998. None of Trenwick's other U.S. insurance  subsidiaries
paid any dividends in 1999, 1998 or 1997.

Under the applicable  laws of the United Kingdom,  Trenwick's U.K.  subsidiaries
may make shareholder  distributions only from accumulated  realized profits, net
of accumulated  realized losses. In addition,  under the UK Insurance  Companies
Act, Trenwick International is not permitted to make any distribution that would
reduce its net assets below the required  minimum margin of solvency  which,  as
determined under the U.K. Financial Service  Authority's rules, is approximately
$16.7 million as of December 31, 1999.  Trenwick  International must also notify
the United Kingdom  Financial  Services  Authority of any proposal to declare or
pay a dividend on any of its share capital. Under Lloyd's regulations, Chartwell
Managing Agents is not permitted to make any  distribution  that would cause its
assets to fall below any of Chartwell  Managing  Agents' share capital,  minimum
net current asset margin or minimum net asset  margin.  As of December 31, 1999,
the highest of the three tests required  Chartwell  Managing  Agents to maintain
approximately $1.1 million of capital.

Investment Limitations

Connecticut, New York and North Dakota laws and regulations govern the types and
amounts of investments  which are permissible for Trenwick's  insurance  company
subsidiaries.  These rules are  designated to ensure the safety and liquidity of
the insurers' investment portfolio.  In general,  these rules permit insurers to
purchase  only  investments  which  are  interest  bearing,  interest  accruing,
entitled to dividends or otherwise income earning and not then in default in any
respect,  and insurers must be entitled to receive for its exclusive account and
benefit the interest or income  accruing  thereon.  No security or investment is
eligible  for  purchase  at a price  above its fair  value or market  value.  In
addition,  these rules require  investments by Trenwick to be  diversified.  The
U.K.  Financial  Services Authority governs the types and amounts of investments
which are  permissible for insurers in the United  Kingdom,  including  Trenwick
International.  Likewise,  Lloyd's  regulations  govern the types and amounts of
investments that are permissible for Chartwell  Managing Agents to make with the
assets of the Lloyd's  syndicates  that it  manages.  These laws  penalize  high
concentrations of riskier types of assets and high exposures to certain types of
issuers. Trenwick believes that it is in compliance with all material applicable
investment laws.

Employees

At December  31, 1999,  Trenwick  employed a total of 124 and 284 persons in its
domestic and international operations,  respectively.  Trenwick has no employees
represented by a labor union and believes that its employee relations are good.

Item 2. Properties

Trenwick's corporate  headquarters and Trenwick America Re's offices are located
in  approximately  46,000  total  square  feet of  leased  office  space  at One
Canterbury Green, Stamford,  Connecticut.  In connection with the acquisition of
Chartwell, Trenwick assumed a lease of approximately 53,000 square feet of space
at Four  Stamford  Plaza in Stamford,  Connecticut.  Chartwell  Managing  Agents
leases approximately 39,000 square feet of space in London, England and Trenwick
International  leases  office  space  in  London,  England  and  Paris,  France.
Management  believes  Trenwick's current office space is adequate for its needs.
See Note 8 of Notes to the Consolidated Financial Statements of Trenwick.




                                       22




Item 3. Legal Proceedings

Trenwick is party to various legal  proceedings  generally arising in the normal
course of its business.  Trenwick does not believe that the eventual  outcome of
any such proceeding  will have a material  effect on its financial  condition or
business. Trenwick's subsidiaries are regularly engaged in the investigation and
the defense of claims arising out of the conduct of their business.  Pursuant to
Trenwick's  insurance  and  reinsurance  arrangements,  disputes  are  generally
required to be finally settled by arbitration.

Item 4. Submission of Matters to a Vote of Security Holders

A  special  meeting  of  stockholders  of  Trenwick  was held in Old  Greenwich,
Connecticut  on  October  7,  1999.  Shareholders  holding  8,680,216  shares of
Trenwick's common stock, 82.8% of the then outstanding  shares, were represented
in person or by proxy.

The proposal to adopt the merger  agreement  between  Trenwick and Chartwell and
approve  the merger of  Chartwell  with and into  Trenwick  and the  issuance of
Trenwick  common stock to Chartwell  stockholders  upon completion of the merger
was approved:  7,881,754 shares voted in favor; 7,884 shares voted against;  and
1,155 shares abstained (including broker non-votes).

The proposal to amend  Trenwick 1993 Stock Option Plan to increase the aggregate
number of shares of Common  Stock  subject to awards  under such plan by 125,000
shares was  approved:  7,584,123  shares  voted in favor;  294,381  shares voted
against; and 801,712 shares abstained (including broker non-votes).


                                       23



                                     PART II

Item 5. Market for Corporation's Common Stock and Related Stockholder Matters

As of October 28, 1999,  Trenwick Common Stock commenced trading on the New York
Stock Exchange under the ticker symbol TWK. Prior to such date,  Trenwick Common
Stock traded on the NASDAQ  National Market System under the ticker symbol TREN.
The following table sets forth for the periods presented below, the high and low
sales price of the  Trenwick  Common  Stock as  reported  by the NASDAQ  through
October  27, 1999 and as  reported  by the NYSE from  October  28, 1999  through
December 31, 1999. On March 27, 2000,  the last reported sales price of Trenwick
Common Stock on the NYSE was $13.81 per share.

Year ended December 31, 1998                         High           Low
                                                     ----           ---
     First Quarter                                  $38.00         $33.75
     Second Quarter                                  41.75          35.50
     Third Quarter                                   39.50          28.00
     Fourth Quarter                                  34.50          27.31

Year ended December 31, 1999
     First Quarter                                   35.00          25.50
     Second Quarter                                  31.94          24.66
     Third Quarter                                   25.06          16.56
     Fourth Quarter                                  21.25          14.75

There were 327  holders of record  and in excess of 2,700  beneficial  owners of
Trenwick Common Stock as of March 24, 2000.

Trenwick  paid a quarterly  cash  dividend of $.25 per share in each  quarter of
1998 and a quarterly  cash  dividend of $.26 per share in each  quarter of 1999.
The  declaration  and payment of future  dividends  will be at the discretion of
Trenwick's  Board of Directors and is subject to certain  legal,  regulatory and
other  restrictions.  For a description of restrictions on Trenwick's ability to
pay  dividends,  reference  is made to Item 1,  Business -  Regulation,  Item 7,
Management's  Discussion  and  Analysis of  Financial  Condition  and Results of
Operations and Item 8, Note 12 of Notes to the Consolidated Financial Statements
of Trenwick.


                                       24



Item 6. Selected Financial Data



                                                            1999            1998            1997            1996            1995
                                                        -----------      -----------     -----------     -----------     -----------
                                                                          (in thousands except per share data)
                                                                                                          
Statement of Operations Data
Net premiums written                                    $   354,610      $   250,219     $   195,230     $   226,364     $   197,162
                                                        ===========      ===========     ===========     ===========     ===========
Net premiums earned                                     $   325,114      $   245,561     $   190,156     $   211,069     $   177,394
Net investment income                                        66,394           56,316          48,402          41,226          36,828
Net realized investment gains                                 1,916            9,016           2,304             299             368
Other income                                                    861              421              10              --              --
                                                        -----------      -----------     -----------     -----------     -----------
Total revenues                                          $   394,285      $   311,314     $   240,872     $   252,594     $   214,590
                                                        ===========      ===========     ===========     ===========     ===========
Net income (loss)                                       $   (11,048)     $    34,792     $    35,252     $    33,848     $    29,841
                                                        ===========      ===========     ===========     ===========     ===========
Per Share Data
Basic Earnings
   Income (loss) before extraordinary item              $      (.94)     $      2.99     $      3.12     $      3.40     $      3.09
                                                        ===========      ===========     ===========     ===========     ===========
   Net income  (loss)                                   $      (.94)     $      2.99     $      3.03     $      3.40     $      3.09
                                                        ===========      ===========     ===========     ===========     ===========
Weighted average shares outstanding                          11,762           11,657          11,645           9,959           9,674
                                                                         ===========     ===========     ===========     ===========
Diluted earnings
   Income (loss) before extraordinary item              $      (.94)     $      2.95     $      3.01     $      2.85     $      2.59
                                                        ===========      ===========     ===========     ===========     ===========
   Net income (loss)                                    $      (.94)     $      2.95     $      3.01     $      2.85     $      2.59
                                                        ===========      ===========     ===========     ===========     ===========
Weighted average shares outstanding                          11,762           11,779          12,265          13,352          13,149
                                                        ===========      ===========     ===========     ===========     ===========
     Dividends                                          $      1.04      $      1.00     $       .97     $       .83     $       .75
                                                        ===========      ===========     ===========     ===========     ===========
Balance Sheet Data
Investments and cash                                    $ 1,749,859      $ 1,005,211     $   864,324     $   754,210     $   653,704
Total assets                                              3,240,599        1,392,261       1,085,956         920,804         820,930
Unpaid claims and claims expenses                         1,964,139          682,428         518,387         467,177         411,874
Long term debt                                              248,905           75,000              --         103,500         103,500
Company  obligated  mandatorily
   redeemable preferred capital
   securities of subsidiary trust
   holding solely junior subordinated
   debentures of Trenwick                                   110,000          110,000         110,000              --              --
Common stockholders' equity                                 462,249          348,029         357,649         265,753         240,776
Shares of common stock outstanding                           16,889           11,051          11,951          10,088           9,886
Book value per share                                    $     27.37      $     31.49     $     29.93     $     26.34     $     24.36



                                       25


Amounts  for  1999  reflect  the  results  of  Chartwell  and its  subsidiaries,
accounted for as a purchase, from October 27, 1999, the date of acquisition.

Amounts for 1998 reflect the results of Trenwick International, accounted for as
a purchase, from February 27, 1998, the date of acquisition.

All share and per share  information  reflects  a 3 for 2 stock  split,  paid on
April 15, 1997.

The earnings per share amounts have been restated to comply with the  accounting
standard, "Earnings per Share"


                                       26




CERTAIN FINANCIAL RATIOS



                                                   1999            1998           1997          1996            1995
                                                   ----            ----           ----          ----            ----
                                                                                                
GAAP Combined ratio                                119.4%          102.3%          96.5%          95.8%          95.6%

Net premiums written to statutory surplus
ratio                                             0.62:1          0.77:1         0.55:1         0.85:1         0.82:1

Unpaid claims and claims expenses to
statutory surplus ratio                           1.75:1          1.96:1         1.45:1         1.76:1         1.71:1


     The  other  information  called  for by this  item  can be found in Item 7,
     Management's  Discussion and Analysis of Financial Condition and Results of
     Operations and Item 8, Financial Statements and Supplementary Data.

Item 7. Management's  Discussion and Analysis of Financial Condition and Results
        of Operations

The  information  called for by this item can be found in Trenwick's 1999 Annual
Report to Stockholders under the caption  "Management's  Discussion and Analysis
of Financial  Condition and Results of Operations" and is incorporated herein by
reference.

Item 7a.  Quantitative and Qualitative Disclosures About Market Risk

This information  called for by this item can be found in Trenwick's 1999 Annual
Report to Stockholders under the caption  "Management's  Discussion and Analysis
of Financial  Condition and Results of Operations" and is incorporated herein by
reference.

Item 8. Financial Statements and Supplementary Data

The  information  called for by this item can be found in Trenwick's 1999 Annual
Report to Stockholders immediately following the section captioned "Management's
Discussion and Analysis of Financial Condition and Results of Operations" and to
the items included in Item 14(a) of this report,  and is incorporated  herein by
reference.

Item  9.  Changes  in and  Disagreements  with  Accountants  on  Accounting  and
          Financial Disclosure

None.

                                    PART III

Item 10. Directors and Executive Officers

The information called for by Item 10 is incorporated herein by reference to the
sections   captioned   "Board  of  Directors",   "Management",   and  "Executive
Compensation"  of  Trenwick's  proxy  statement  for its 2000 Annual  Meeting of
Stockholders (the "Proxy Statement").



                                       27



Item 11. Executive Compensation

The information called for by Item 11 is incorporated herein by reference to the
section captioned "Executive Compensation" of the Proxy Statement.

Item 12. Security Ownership of Certain Beneficial Owners and Management

The information called for by Item 12 is incorporated herein by reference to the
section captioned "Principal Stockholders" of the Proxy Statement.

Item 13. Certain Relationships and Related Transactions

The information called for by Item 13 is incorporated herein by reference to the
section captioned "Election of Directors" of the Proxy Statement.

                                     PART IV

Item 14. Exhibits, Financial Statement Schedules and Reports on Form 8-K.

(a)     Documents

(1)&(2) The  Financial  Statements,  Schedules  and the  Report  of  Independent
        Accountants  on  the  Financial  Statement  Schedules,   listed  in  the
        accompanying index on Page 34, are filed as part of this Report.

(3)     Exhibits

        3.1     Restated   Certificate   of   Incorporation   of  Trenwick  with
                Certificates of Amendment thereto.  Incorporated by reference to
                Exhibit 3.1 to Trenwick's  Quarterly Report on Form 10-Q for the
                quarter ended June 30, 1997 (File No. 0-14737).

        3.2     (a)     Certificate of Elimination  amending Trenwick's Restated
                        Certificate of  Incorporation to eliminate all reference
                        to  Series  A  Junior  Participating   Preferred  Stock.
                        Incorporated   by   reference   to  Exhibit   3.1(a)  to
                        Trenwick's Quarterly Report on Form 10-Q for the quarter
                        ended September 30, 1997 (File No. 1-15389).

                (b)     Certificate   of   Designation   amending  the  Restated
                        Certificate  of  Incorporation  of  Trenwick  to  create
                        Series   B   Junior   Participating   Preferred   Stock.
                        Incorporated   by   reference   to  Exhibit   3.2(b)  to
                        Trenwick's Quarterly Report on Form 10-Q for the quarter
                        ended September 30, 1997 (File No. 1-15389).

        3.3     Trenwick's By-laws.  Incorporated by reference to Exhibit 3.2 to
                Trenwick's   Registration   Statement  on  Form  S-1  (File  No.
                33-5085).

        4.1     Rights  Agreement,  dated  as of  September  24,  1997,  between
                Trenwick and First Chicago Trust Company of New York  including,
                as Exhibit A thereto, a form of Rights Certificate. Incorporated
                by reference to Exhibit 1 to Trenwick's Form 8-A filed September
                24, 1997 (File No. 1-15389).



                                       28



        4.2     Amendment  No. 1 to Rights  Agreement,  dated as of December 19,
                1999,  between  Trenwick and First  Chicago Trust Company of New
                York.  Incorporated by reference to Exhibit 1 to Trenwick's Form
                8-A filed January 13, 2000 (File No. 1-15389).

        4.3     (a)     Indenture  dated as of January  31,  1997,  between  The
                        Chase  Manhattan  Bank  and  Trenwick.  Incorporated  by
                        reference to Exhibit 4.2(a) to Trenwick's  Annual Report
                        on Form 10-K for the year ended  December 31, 1996 (File
                        No. 0-14737).

                (b)     Amended and  Restated  Declaration  of Trust of Trenwick
                        Capital   Trust  I  dated  as  of  January   31,   1997.
                        Incorporated   by   reference   to  Exhibit   4.2(b)  to
                        Trenwick's Annual Report on Form 10-K for the year ended
                        December 31, 1996 (File No. 0-14737).

                (c)     Exchange Capital Securities Guarantee Agreement dated as
                        of  July  25,  1997,  between  Trenwick  and  The  Chase
                        Manhattan Bank, as Trustee. Incorporated by reference to
                        Exhibit 4.7 to Trenwick's Registration Statement on Form
                        S-4 (File No. 333-28707).

        4.4     Indenture  dated as of March 27, 1998  between  Trenwick and The
                First  National  Bank of Chicago,  as Trustee,  with  respect to
                Trenwick's $75 million principal amount of 6.7% Senior Notes due
                April 1, 2003,  incorporated  by  reference  to  Exhibit  4.2 to
                Trenwick's  Quarterly  Report on Form 10-Q for the quarter ended
                March 31, 1998 (File No. 1-15389).

        4.5     Indenture,  dated as of March 17,  1994,  between  Chartwell  Re
                Corporation  and Bankers Trust Company,  as Trustee,  for the 10
                1/4% Senior Notes due 2004. Incorporated by reference to Exhibit
                4.1 to Chartwell Re Corporation's Registration Statement on Form
                S-1 (File No. 33-75386).

        4.6     First  Supplemental  Indenture,  dated as of December  12, 1995,
                among   Chartwell   Re   Corporation,   Chartwell   Re  Holdings
                Corporation  and Bankers Trust Company,  as Trustee,  for the 10
                1/4Senior  Notes due 2004.  Incorporated by reference to Exhibit
                4.3 to Chartwell Re Corporation's Registration Statement on Form
                S-1 (File No. 333-678).

        4.7     Second  Supplemental  Indenture,  dated as of December 12, 1995,
                between  Chartwell  Re Holdings  Corporation  and Bankers  Trust
                Company,  as  Trustee,  for the 10 1/4  Senior  Notes  due 2004.
                Incorporated  by  reference  to  Exhibit  4.4  to  Chartwell  Re
                Corporation's  Registration  Statement  on Form  S-1  (File  No.
                333-678).

        4.8     Indenture,  dated as of December 1, 1995,  between  Chartwell Re
                Corporation,  as the  successor to Piedmont  Management  Company
                Inc., and Fleet Bank, as Trustee,  for the  Contingent  Interest
                Notes due June 30,  2006.  Incorporated  by reference to Exhibit
                4.5 to Chartwell Re Corporation's Registration Statement on Form
                S-1 (File No. 333-678).

        4.9     First  Supplemental  Indenture,  dated as of December  13, 1995,
                among Piedmont Management Company,  Chartwell Re Corporation and
                Fleet Bank, as Trustee under the  Contingent  Interest Notes due
                June 30,  2006.  Incorporated  by  reference  to Exhibit  4.6 to
                Chartwell Re  Corporation's  Registration  Statement on Form S-1
                (File No. 333-678).



                                       29



        10.1    Credit Agreement, dated as of November 24, 1999, among Trenwick,
                various  lending  institutions,  First Union  National  Bank, as
                Syndication Agent, Fleet National Bank, as Documentation  Agent,
                and Chase Manhattan Bank, as Administrative Agent.

        10.2    Amendment  No. 1 to Credit  Agreement,  dated as of December 31,
                1999 among Trenwick,  various lending institutions,  First Union
                National  Bank, as  Syndication  Agent,  Fleet National Bank, as
                Documentation Agent, and Chase Manhattan Bank, as Administrative
                Agent.

        10.3    Stockholders  Agreement,  dated as of December 13, 1995, between
                Chartwell Re Corporation  and the security  holders named in the
                schedule of holders attached thereto.  Incorporated by reference
                to  Exhibit  10.3 to  Chartwell  Re  Corporation's  Registration
                Statement on Form S-1 (File No. 333-678).

        10.4    Registration  Rights  Agreement,  dated as of December 13, 1995,
                between  Chartwell Re Corporation and the security holders named
                in the schedule of holders  attached  thereto.  Incorporated  by
                reference  to  Exhibit   10.4  to  Chartwell  Re   Corporation's
                Registration Statement on Form S-1 (File No. 333-678).

        10.5    Common Stock Purchase  Warrant,  dated March 6, 1992,  issued by
                Chartwell  Re  Corporation  to Wand  Partners  (Chartwell)  L.P.
                Incorporated  by  reference  to Exhibit  10.34 to  Chartwell  Re
                Corporation's  Registration  Statement  on Form  S-1  (File  No.
                33-75386).

        10.6    Common Stock Purchase  Warrant,  dated December 31, 1992, issued
                by Chartwell to Wand Partners  (Chartwell) L.P.  Incorporated by
                reference  as  Exhibit  10.35  to  Chartwell  Re   Corporation's
                Registration Statement on Form S-1 (File No. 33-75386).

        10.7    Common Stock Purchase  Warrant,  dated December 31, 1992, issued
                by Chartwell to John Sagan. Incorporated by reference to Exhibit
                10.36 to Chartwell Re  Corporation's  Registration  Statement on
                Form S-1 (File No. 33-75386).

        10.8    Form of Common Stock  Purchase  Warrants,  dated March 17, 1994,
                issued by Chartwell Re Corporation to Wand/Chartwell Investments
                L.P.  and to the  holders  of the  Series A Stock,  the Series B
                Stock  and the  Series  C Stock  of  Chartwell  Re  Corporation.
                Incorporated  by  reference  to  Exhibit  4.2  to  Chartwell  Re
                Corporation's  Quarterly  Report  on Form  10-Q for the  quarter
                ended March 31, 1994 (File No. 1-12502).

        10.9    Trenwick  1989 Stock Plan,  as amended  through  August 3, 1993.
                Incorporated  by reference to Exhibit 10.8 to Trenwick's  Annual
                Report on Form 10-K for the year ended  December  31, 1994 (File
                No. 0-14737).*

        10.10   Trenwick  1993 Stock  Option  Plan,  as amended  through May 21,
                1998.  Incorporated  by  reference  to Appendix A to  Trenwick's
                Proxy  Statement  for the 1998  Annual  Meeting of  Stockholders
                (File No. 1-15389).*

        10.11   Trenwick  1993 Stock  Option  Plan for  Non-Employee  Directors.
                Incorporated   by  reference  to  Exhibit  10.2  to   Trenwick's
                Quarterly  Report on Form 10-Q for the  quarter  ended  June 30,
                1994 ( File No. 0-14737).*

        10.12   Trenwick  Unfunded  Supplemental  Executive  Retirement Plan, as
                amended through December 14, 1993.  Incorporated by reference to
                Exhibit 10.14 to  Trenwick's  Annual Report on Form 10-K for the
                year ended December 31, 1994 (File No. 0-14737).*



                                       30



        10.13   Leased Automobile Policy for executive officers. Incorporated by
                reference to Exhibit 10.5 to  Trenwick's  Annual  Report on Form
                10-K for the year ended December 31, 1998. (File No. 1-15389).*

        10.14   Description of life insurance and long-term disability insurance
                coverage for executive  officers.  Incorporated  by reference to
                Exhibit 10.16 to  Trenwick's  Annual Report on Form 10-K for the
                year ended December 31, 1994 (File No. 0-14737).*

        10.15   Trenwick Directors Deferred  Compensation Plan.  Incorporated by
                reference to Exhibit 10.17 to  Trenwick's  Annual Report on Form
                10-K for the year ended December 31, 1994 (File No. 0-14737).*

        10.16   Description of Trenwick Directors Retirement Plan.  Incorporated
                by reference to Exhibit  10.18 to  Trenwick's  Annual  Report on
                Form  10-K  for the year  ended  December  31,  1994  (File  No.
                0-14737).*

        10.17   Declaration of Trust dated December 10, 1996, as amended through
                September 9, 1997,  establishing  a retirement  plan for certain
                employees of Trenwick Management Services Limited.  Incorporated
                by reference to Exhibit 10.9 to Trenwick's Annual Report on Form
                10-K for the year ended December 31, 1998. (File No. 1-15389).*

        10.18   1993 Stock Option Plan of Chartwell Re Corporation. Incorporated
                by  reference to Exhibit  10.14 to  Chartwell  Re  Corporation's
                Registration Statement on Form S-4 (File No. 33-97010).*

        10.19   Chartwell Re Corporation 1996 Non-Employee Director Stock Option
                Plan.  Incorporated by reference to Exhibit 4(c) to Chartwell Re
                Corporation's  Registration  Statement  on Form  S-8  (File  No.
                333-12203).*

        10.20   Chartwell Re  Corporation  1997 Omnibus  Stock  Incentive  Plan.
                Incorporated   by   reference  to  Exhibit  A  to  Chartwell  Re
                Corporation's  Definitive  Proxy Statement on Schedule 14A filed
                with the Securities  and Exchange  Commission on April 11, 1997.
                (File No. 1-12502).*

        10.21   Employment  Agreement,  dated  as of  March  31,  1993,  between
                Chartwell Re Corporation  and Steven J. Bensinger . Incorporated
                by  reference to Exhibit  10.20 to  Chartwell  Re  Corporation's
                Registration Statement on Form S-1 (File No. 33-75386).*

        10.22   Fourth  Amendment  to  the  Employment  Agreement,  dated  as of
                December 31, 1997,  between  Chartwell Re Corporation and Steven
                J.  Bensinger.  Incorporated  by reference  to Exhibit  10.34 to
                Chartwell Re  Corporation's  Annual  Report on Form 10-K for the
                year ended December 31, 1997 (File No. 1-12502).*

        10.23   Fifth Amendment to the Employment Agreement,  dated as of August
                4,  1998,   between  Chartwell  Re  Corporation  and  Steven  J.
                Bensinger.   Incorporated  by  reference  to  Exhibit  10.23  to
                Chartwell Re  Corporation's  Annual  Report on Form 10-K for the
                year ended December 31, 1998 (File No. 1-12502).*

        10.24   Sixth  Amendment  to  the  Employment  Agreement,  dated  as  of
                December 30, 1998,  between  Chartwell Re Corporation and Steven
                J.  Bensinger.  Incorporated  by reference  to Exhibit  10.26 to
                Chartwell Re  Corporation's  Annual  Report on Form 10-K for the
                year ended December 31, 1998 (File No. 1-12502).*



                                       31



        10.25   Employment  Assumption  and  Amendment  Agreement,  dated  as of
                October 25, 1999, between Trenwick and Steven J. Bensinger.*

        10.26   Service  Agreement,  dated  October  26,  1995,  between  Sorema
                Underwriting Management Limited, Sorema (UK) Reinsurance Limited
                and  Russell  John  English,  as  amended by the Deed of Waiver,
                dated February 27, 1998.*

        10.27   Change of Control  Agreement,  dated  November 3, 1999,  between
                Trenwick and James F. Billett, Jr.*

        10.28   Form of Change of Control  Agreement,  dated  November  3, 1999,
                between Trenwick and senior officers of Trenwick.*

        10.29   Office lease between Trenwick and EOP-Canterbury  Green,  L.L.C.
                dated as of January 29,  1998,  with  respect to office space in
                Stamford,  Connecticut.  Incorporated  by  reference  to Exhibit
                10.16 to  Trenwick's  Annual  Report  on Form  10-K for the year
                ended December 31, 1997 (File No. 1-15389).

        10.30   First  Amendment  dated as of March 31,  1998,  to office  lease
                between Trenwick and  EOP-Canterbury  Green L.L.C. dated January
                29,  1998.   Incorporated  by  reference  to  Exhibit  10.11  to
                Trenwick's  annual  Report  on  Form  10-K  for the  year  ended
                December 31, 1998 (File No. 1-15389).

        10.31   Office Lease Agreement  between AML-Four  Stamford Plaza Limited
                Partnership and Chartwell Re Corporation,  dated March 29, 1996,
                of the  premises  located  at  Four  Stamford  Plaza,  Stamford,
                Connecticut.

        10.32   Lease  of the  premises  located  at 2  Minster  Court,  London,
                England, by and between Chartwell UK Management Services Limited
                (as Tenant) and The  Prudential  Assurance  Company  Limited (as
                Landlord).

        10.33   Underlease  between  Wereldhave  Property  Corporation  PLC  and
                predecessors of Trenwick  Management  Services Limited dated May
                22, 1991,  with respect to office space located at 16 Eastcheap,
                London,  England.  Incorporated by reference to Exhibit 10.12 to
                Trenwick's  Annual  Report  on  Form  10-K  for the  year  ended
                December 31, 1998 (File No. 1-15389).

        10.34   Coinsured Aggregate Excess of Loss Reinsurance Agreement between
                Trenwick   and   Centre   Reinsurance   Company   of  New  York.
                Incorporated by reference to Exhibit 10.28 to Trenwick's  Annual
                Report on Form 10-K for the year ended  December  31, 1994 (File
                No. 0-14737).

        10.35   Aggregate  Excess  of Loss  Ratio  Cover  between  Trenwick  and
                Continental  Casualty  Company.  Incorporated  by  reference  to
                Exhibit 10.22 to  Trenwick's  Annual Report on Form 10-K for the
                year ended December 31, 1995 (File No. 0-14737).

        10.36   1996 Coinsured  Aggregate Excess of Loss  Reinsurance  Agreement
                between Trenwick and Centre Reinsurance  Company of New York and
                CNA Re. Incorporated by reference to Exhibit 10.33 to Trenwick's
                Annual Report on Form 10-K for the year ended  December 31, 1996
                (File No. 0-14737).



                                       32



        10.37   First and Second Coinsured  Aggregate Excess of Loss Reinsurance
                Agreement between Trenwick and Centre Reinsurance Company of New
                York and CNA Re.  Incorporated  by reference to Exhibit 10.31 to
                Trenwick's  Annual  Report  on  Form  10-K  for the  year  ended
                December 31, 1997 (File No. 1-15389).

        10.38   1998 Coinsured  Aggregate Excess of Loss  Reinsurance  Agreement
                between Trenwick and Centre Reinsurance  Company of New York and
                National  Union.  Incorporated  by reference to Exhibit 10.27 to
                Trenwick's  Annual  Report  on  Form  10-K  for the  year  ended
                December 31, 1998 (File No. 1-15389).

        10.39   1999 Coinsured  Aggregate Excess of Loss  Reinsurance  Agreement
                between  Trenwick  and Centre  Insurance  Company  and  National
                Union.

        10.40   Aggregate  Excess  of Loss  Reinsurance  Agreement,  dated as of
                October 27, 1999, by and between Chartwell  Reinsurance Company,
                Dakota Specialty Insurance Company, The Insurance Corporation of
                New York and Drayton  Company  Limited,  inclusive  of corporate
                capital support of London  underwriting  operations,  and London
                Life  and  Casualty  Reinsurance  Corporation  and  Scandinavian
                Reinsurance Company, Ltd.

        12.1    Computation of Ratios.

        13.1    Excerpts  from  Trenwick's  1999 Annual  Report to  Stockholders
                expressly incorporated by reference in this Form 10-K.

        21.1    List of Subsidiaries.

        23.1    Consent of PricewaterhouseCoopers LLP.

        27.1    Financial Data Schedule.

        *Management contract or compensatory plan or arrangement.

(b)     Reports on Form 8-K

        A Report on Form 8-K was filed on December 22,  1999,  which stated that
        Trenwick  and the  LaSalle  Re  Holdings  Limited  had  entered  into an
        Agreement,   Scheme  of   Arrangement,   Plan  of  Merger  and  Plan  of
        Reorganization,  dated as of December 19, 1999,  and that in  connection
        with this  Agreement,  Trenwick  and  LaSalle Re  Holdings  Limited  had
        entered into Stock Option Agreement with each other, each dated December
        19, 1999 and  Trenwick and certain  shareholders  of LaSalle Re Holdings
        Limited  and  LaSalle  Re  Limited  had  entered  into  a   Shareholders
        Agreement.  The Report on Form 8-K also stated that Trenwick and LaSalle
        Re  Holdings  Limited had issued a joint press  release  announcing  the
        signing of the agreements.


                                       33




                                   SIGNATURES

Pursuant to the  Requirements of Section 13 or 15(d) of Securities  Exchange Act
of 1934,  the  registrant has duly caused this report to be signed on its behalf
by the undersigned, thereunto duly authorized.

                               TRENWICK GROUP INC.
                                  (Registrant)

                               By /s/ James F. Billett, Jr.
                                 ---------------------------------
                                  James F. Billett, Jr.
                                 Chairman, President and
                                 Chief Executive Officer

Dated: March 30, 2000

Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following  persons on behalf of the  registrant and
in the capacities and on the dates indicated.



Signature                                       Title                               Date
- - ---------                                       -----                               ----
                                                                         
  /s/James F. Billett, Jr.             Chairman of the Board,                  March 30, 2000
- - -------------------------------         President and Chief
     James F. Billett, Jr.              Executive Officer and
                                        Director (Principal
                                        Executive Officer)

  /s/Alan L. Hunte                     Vice President and                      March 30, 2000
- - -------------------------------         Treasurer (Principal
     Alan L. Hunte                      Financial Officer and
                                        Accounting Officer)

  /s/W. Marston Becker                 Director                                March 30, 2000
- - -------------------------------
     W. Marston Becker

  /s/Anthony S. Brown                  Director                                March 30, 2000
- - -------------------------------
     Anthony S. Brown

  /s/Richard E. Cole                   Director                                March 30, 2000
- - -------------------------------
     Richard E. Cole



                                       34




                                                                         

  /s/Robert M. DeMichele               Director                                March 30, 2000
- - -------------------------------
     Robert M. De Michele

  /s/Neil Dunn                         Director                                March 30, 2000
- - -------------------------------
     Neil Dunn

  /s/Frank E. Grzelecki                Director                                March 30, 2000
- - -------------------------------
     Frank E. Grzelecki

  /s/P. Anthony Jacobs                 Director                                March 30, 2000
- - -------------------------------
     P. Anthony Jacobs

  /s/Joseph D. Sargent                 Director                                March 30, 2000
- - -------------------------------
     Joseph D. Sargent

  /s/Frederick D. Watkins              Director                                March 30, 2000
- - -------------------------------
     Frederick D. Watkins

  /s/Stephen R. Wilcox                 Director                                March 30, 2000
- - -------------------------------
     Stephen R. Wilcox



                                       35


                      TRENWICK GROUP INC. AND SUBSIDIARIES

                   INDEX TO FINANCIAL STATEMENTS AND SCHEDULES



                                                                                                  Pages
                                                                                                  -----
                                                                                               
Financial Statements:

  Report of Independent Accountants
  on Consolidated Financial Statements...........................................................    *

  Consolidated Balance Sheet at December 31, 1999 and 1998 ......................................    *

  Consolidated Statement of Income and Comprehensive Income
       for the years ended December 31, 1999, 1998 and 1997......................................    *

  Consolidated Statement of Changes in Stockholders' Equity
       for the years ended December 31, 1999, 1998 and 1997......................................    *

  Consolidated Statement of Cash Flows
       for the years ended December 31, 1999, 1998 and 1997......................................    *

  Notes to Consolidated Financial Statements.....................................................    *


Financial Statement Schedules:

     II   -   Condensed Financial Information of Registrant ..................................... S-1-S-3

     III  -   Supplementary Insurance Information ...............................................   S-4

     IV   -   Valuation and Qualifying Accounts..................................................   S-5

Report of Independent Accountants on Financial Statement
     Schedules ..................................................................................   S-6



*    Incorporated by reference to Trenwick's 1999 Annual Report to Stockholders.

Schedules  other than those listed  above are omitted  since they are either not
required or are not applicable or the  information  required is presented in the
consolidated financial statements, including the notes thereto.





                      TRENWICK GROUP INC. AND SUBSIDIARIES
            SCHEDULE II-CONDENSED FINANCIAL INFORMATION OF REGISTRANT

                               TRENWICK GROUP INC.
                                  BALANCE SHEET
                              (Parent Company Only)

                                                                 December 31,
                                                             1999         1998
                                                           --------     --------
                                                                (in thousands)
Assets:
     Investments in consolidated subsidiaries              $607,343     $532,069
     Cash and cash equivalents                                2,331          523
     Due from consolidated subsidiaries                         177        4,287
     Deferred debt issuance costs                             6,388        2,463
     Accrued investment income                                  128          125
     Net deferred income taxes                               15,000        4,198
     Goodwill                                               153,824        1,605
     Other assets                                            17,578            9
                                                           --------     --------

     Total assets                                          $802,769     $545,279
                                                           ========     ========

Liabilities:
     6.70% Senior notes due 2003                           $ 75,000     $ 75,000
     Junior subordinated debentures                         113,403      113,403
     Contingent interest notes                               34,699           --
     Due to consolidated subsidiaries                        10,965        2,700
     Accrued interest expense                                 5,497        5,424
     Chase syndicated senior credit facilities               94,501           --
     Other liabilities                                        6,455          723
                                                           --------     --------

     Total liabilities                                      340,520      197,250

Stockholders' equity                                        462,249      348,029
                                                           --------     --------

     Total liabilities and stockholders' equity            $802,769     $545,279
                                                           ========     ========


                                      S-1




                      TRENWICK GROUP INC. AND SUBSIDIARIES
     SCHEDULE II--CONDENSED FINANCIAL INFORMATION OF REGISTRANT-(continued)

                               TRENWICK GROUP INC.
                               STATEMENT OF INCOME
                              (Parent Company Only)



                                                           Year ended December 31,
                                                      --------------------------------
                                                        1999        1998        1997
                                                      --------    --------    --------
                                                               (in thousands)
                                                                     
Revenues:
Consolidated subsidiary dividends                     $ 46,100    $ 26,600    $  8,250
Net investment income                                      358       1,500       4,974
Net realized investment gains                               --         778          --
Other income                                                 1          12          --
                                                      --------    --------    --------

     Total revenues                                     46,459      28,890      13,224

Interest and operating expenses                         16,938      13,950      10,090
Amortization expense                                     1,423          33          --

Income before income taxes, equity in undistributed
     income of unconsolidated subsidiaries and
     extraordinary item                                 28,098      14,907       3,134
Income tax benefit                                      (5,077)     (3,942)     (1,239)
                                                      --------    --------    --------
Income before equity in undistributed income of
     consolidated subsidiaries                          33,175      18,849       4,373
Equity in undistributed income (loss) of consolidated
     subsidiaries                                      (44,223)     15,943      31,916
                                                      --------    --------    --------
Income (loss) before extraordinary loss on
     debt redemption                                   (11,048)     34,792      36,289
Extraordinary loss on debt redemption, net of $558
     income tax benefit                                     --          --       1,037
                                                      --------    --------    --------
Net income (loss)                                     $(11,048)   $ 34,792    $ 35,252
                                                      =========   ========    ========



                                      S-2





                      TRENWICK GROUP INC. AND SUBSIDIARIES
     SCHEDULE II--CONDENSED FINANCIAL INFORMATION OF REGISTRANT-(continued)

                               TRENWICK GROUP INC.
                             STATEMENT OF CASH FLOWS
                              (Parent Company Only)



                                                                             Year ended December 31,
                                                                 -----------------------------------------------
                                                                    1999              1998               1997
                                                                 ---------          ---------          ---------
                                                                                 (in thousands)
                                                                                              
Cash flows from operating activities:
     Dividends and net investment income received                $  46,466          $  28,548          $  12,642
     Interest and operating expenses paid                          (14,979)           (11,786)            (4,983)
     Income taxes received                                           3,669              5,035                794
                                                                 ---------          ---------          ---------

     Cash provided by operating activities                          35,156             21,797              8,453
                                                                 ---------          ---------          ---------
Cash flows from investing activities:
     Purchases of debt securities                                       --            (16,637)           (72,932)
     Sales of debt securities                                           --             88,190                 --
     Maturities of debt securities                                      --                911             16,050
     Investment in subsidiaries                                    (57,474)          (130,582)            (3,403)
                                                                 ---------          ---------          ---------

     Cash used for investing activities                            (57,474)           (58,118)           (60,285)
                                                                 ---------          ---------          ---------
Cash flows from financing activities:
     Issuance of senior notes                                           --             75,000                 --
     Issuance of junior subordinated debentures                         --                 --            113,403
     Issuance costs of senior notes and capital securities          (4,055)              (922)            (1,669)
     Long term debt proceeds                                        94,473                 --                 --
     Redemption of convertible debentures                               --                 --            (46,997)
     Issuance of common stock                                           --              1,536                956
     Repurchase of common stock                                    (44,604)           (34,880)              (171)
     Dividends paid                                                (12,787)           (11,698)           (11,546)
     Intercompany loans                                             (8,901)             2,700                 --
                                                                 ---------          ---------          ---------

     Cash provided by financing activities                          24,126             31,736             53,976
                                                                 ---------          ---------          ---------

Change in cash and cash equivalents                                  1,808             (4,585)             2,144

Cash and cash equivalents, beginning of year                           523              5,108              2,964
                                                                 ---------          ---------          ---------

Cash and cash equivalents, end of year                           $   2,331          $     523          $   5,108
                                                                 =========          =========          =========



                                      S-3






                      TRENWICK GROUP INC. AND SUBSIDIARIES
               SCHEDULE III -- SUPPLEMENTARY INSURANCE INFORMATION

                                 (in thousands)



                                                                               1999        1998       1997
                                                                            ---------    -------     -------
                                                                                            
Deferred policy acquisition costs     Trenwick America Re                     $34,757    $21,023     $22,524
                                      Canterbury Financial Group                3,215         --          --
                                      Trenwick International                   19,982     14,238          --
                                      Chartwell Managing Agents                20,942         --          --
                                                                            ---------    -------     -------
                                                                               78,896     35,261      22,524

Unpaid claims and claim expenses      Trenwick America Re                   1,201,954    546,292     518,387
                                      Canterbury Financial Group              142,215         --          --
                                      Trenwick International                  164,264    136,136          --
                                      Chartwell Managing Agents               455,706         --          --
                                                                            ---------    -------     -------
                                                                            1,964,139    682,428     518,387

Unearned premium income               Trenwick America Re                     110,909     75,206      87,020
                                      Canterbury Financial Group               63,133
                                      Trenwick International                  100,336     76,845          --
                                      Chartwell Managing Agents               105,306
                                                                            ---------    -------     -------
                                                                              379,684    152,051      87,020

Net premiums earned                   Trenwick America Re                     166,906    174,443     190,156
                                      Canterbury Financial Group               10,343
                                      Trenwick International                  107,911     71,118          --
                                      Chartwell Managing Agents                39,954
                                                                            ---------    -------     -------
                                                                              325,114    245,561     190,156

Net Investment Income                 Trenwick America Re                      49,315     44,490      43,692
                                      Canterbury Financial Group                1,722
                                      Trenwick International                   11,253     10,614          --
                                      Chartwell Managing Agents                 3,845
                                      Unallocated                                 259      1,212       4,710
                                                                            ---------    -------     -------
                                                                               66,394     56,316      48,402

Claims and claims expenses incurred   Trenwick America Re                     130,603    105,478     109,554
                                      Canterbury Financial Group                5,766
                                      Trenwick International                   80,866     47,657          --
                                      Chartwell Managing Agents                37,303
                                                                            ---------    -------     -------
                                                                              254,538    153,135     109,554

Policy acquisition costs              Trenwick America Re                      61,633     58,310      58,549
                                      Canterbury Financial Group                  916
                                      Trenwick International                   22,627     15,887          --
                                      Chartwell Managing Agents                10,919
                                                                            ---------    -------     -------
                                                                               96,095     74,197      58,549

Underwriting expenses                 Trenwick America Re                      13,790     13,789      15,425
                                      Canterbury Financial Group                2,687
                                      Trenwick International                   15,364     10,006          --
                                      Chartwell Managing Agents                 5,548
                                                                            ---------    -------     -------
                                                                               37,389     23,795      15,425

Net premiums written                  Trenwick America Re                     155,108    169,112     195,230
                                      Canterbury Financial Group                5,641
                                      Trenwick International                  129,399     81,107          --
                                      Chartwell Managing Agents                64,462
                                                                            ---------    -------     -------
                                                                              354,610    250,219     195,230



                                      S-4





                      TRENWICK GROUP INC. AND SUBSIDIARIES
                 SCHEDULE V - VALUATION AND QUALIFYING ACCOUNTS
                  YEARS ENDED DECEMBER 31, 1999, 1998 AND 1997
                                 (in thousands)


                                        Balance at    Charged to      Balance at
                                       Beginning of    Costs and       End of
                                          Period       Expenses        Period
                                       ------------   ----------      ----------
Year Ended December 31, 1999
Reinsurance recoverable:
  Allowance for Uncollectible
      Reinsurance (1) ..............     $6,402         $  167         $6,569


Year Ended December 31, 1998
Reinsurance recoverable:
  Allowance for Uncollectible
      Reinsurance (1) ..............     $6,394         $    8         $6,402


Year Ended December 31, 1997
Reinsurance recoverable:
  Allowance for Uncollectible
      Reinsurance (1) ..............     $5,731         $  663         $6,394


(1)  Trenwick has a reinsurance  agreement which protects  Trenwick from certain
     uncollectible  reinsurance balances.  Uncollectible amounts have been ceded
     to said  contract  and are  reflected  as  reinsurance  recoverable  in the
     balance sheet.  Deductions to reserve represent  subsequent  collections of
     amounts deemed uncollectible.


                                      S-5





                      Report of Independent Accountants on
                          Financial Statement Schedules

To the Board of Directors of
Trenwick Group Inc.

Our audits of the consolidated  financial  statements  referred to in our report
dated February 29, 2000,  appearing in the 1999 Annual Report to Stockholders of
Trenwick  Group Inc.  (which report and  consolidated  financial  statements are
incorporated  by reference in the Annual  Report on Form 10-K) also  included an
audit of the  financial  statement  schedules  listed in this Form 10-K.  In our
opinion,  these financial  statement  schedules  present fairly, in all material
respects,  the information  set forth therein when read in conjunction  with the
related consolidated financial statements.

PricewaterhouseCoopers  LLP

New York, New York
February 29, 2000

                                      S-6