<Page>


                       SECURITIES AND EXCHANGE COMMISSION


                             Washington, D.C. 20549


                                   FORM 8-K/A


                 Current Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934


                                  June 22, 2001
- --------------------------------------------------------------------------------
                Date of Report (Date of earliest event reported)


                             Arch Capital Group Ltd.
- --------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)


         Bermuda                    0-26456                         N/A
- --------------------------------------------------------------------------------
(State or other jurisdiction    (Commission File              (I.R.S. Employer
    of incorporation or              Number)                 Identification No.)
      organization)


                 20 Horseneck Lane, Greenwich, Connecticut 06830
- --------------------------------------------------------------------------------
               (Address of principal executive offices) (Zip Code)


               Registrant's telephone number, including area code:

                                 (203) 862-4300


                                 Not Applicable
- --------------------------------------------------------------------------------
          (Former name or former address, if changed since last report)

<Page>

ITEM 2.       ACQUISITION OR DISPOSITION OF ASSETS

         On June 22, 2001, Arch Capital Group Ltd., a Bermuda company ("ACGL"),
acquired all of the capital stock of Altus Holdings, Ltd. ("Altus"), a Cayman
Islands company, that it did not already own, pursuant to a reorganization
agreement (the "Reorganization Agreement") dated as of March 23, 2001, by and
among Altus, ACGL and the other shareholders of Altus, for a purchase price of
approximately $38.8 million. The purchase price consisted of approximately $38.4
million in cash and 24,200 ACGL Common Shares issued to employee shareholders
continuing in management positions. Prior to the acquisition, ACGL owned a
minority interest in Altus' common stock which was previously accounted for
under "fair value".

         Following the acquisition, Altus' name was changed to Arch Risk
Transfer Services Ltd. Arch Risk Transfer Services Ltd., through its
wholly-owned subsidiaries, including First American Insurance Company, an
admitted insurer with licenses in 49 states, provides insurance and alternative
risk transfer services through rent-a-captive and other facilities. The
conformed executed copy of the Reorganization Agreement and the press releases
relating to the transaction are filed as exhibits to ACGL's report on Form 8-K
filed with the SEC on July 6, 2001, and are incorporated herein by reference.









                                       1
<Page>

ITEM 7.       FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

(a)      FINANCIAL STATEMENTS OF BUSINESS ACQUIRED.

   Audited Consolidated Financial Statements of Altus:

     Independent Auditors' Report
     Consolidated Balance Sheets - December 31, 2000 and 1999
     Consolidated Statements of Operations - Years Ended December 31,
       2000 and 1999
     Consolidated Statements of Shareholders' Equity - Years Ended
       December 31, 2000 and 1999
     Consolidated Statements of Cash Flows - Years Ended December 31,
       2000 and 1999
     Notes to Consolidated Financial Statements - Years Ended
       December 31, 2000 and 1999

   Unaudited Consolidated Financial Statements of Altus:

     Unaudited Consolidated Balance Sheets - March 31, 2001 and 2000
     Unaudited Consolidated Statements of Operations - For the Three Months
       Ended March 31, 2001 and 2000
     Unaudited Consolidated Statements of Cash Flows - For the Three Months
       Ended March 31, 2001 and 2000
     Notes to the Unaudited Consolidated Financial Statements - For the Three
       Months Ended March 31, 2001 and 2000

(b)      PRO FORMA FINANCIAL INFORMATION.

   Unaudited Pro Forma Condensed Combined Financial Statements of ACGL
   and Altus:

     Unaudited Pro Forma Condensed Combined Balance Sheet - March 31, 2001
     Unaudited Pro Forma Condensed Combined Statement of Income - For the Three
       Months Ended March 31, 2001
     Unaudited Pro Forma Condensed Combined Statement of Income - For the Year
       Ended December 31, 2000
     Notes to the Unaudited Pro Forma Condensed Combined Financial Statements

(c)      EXHIBITS.

         10.1.    Reorganization Agreement, dated as of March 23, 2001, by and
                  among Altus Holdings, Ltd., The Trident Partnership, L.P.,
                  TRYCO II, Ltd., Marsh & McLennan Risk Capital Holdings, Ltd.,
                  Glenn L. Ballew, David G. May and Arch Capital Group Ltd.
                  ("ACGL") (filed as an exhibit to ACGL's Report on Form 8-K, as
                  filed with the SEC on July 6, 2001, and incorporated by
                  reference).

         23(a)    Consent of Independent Accountants.

         99.1.    Press Release, dated March 23, 2001 (filed as an exhibit to
                  ACGL's Report on Form 8-K, as filed with the Securities and
                  Exchange Commission on July 6, 2001, and incorporated by
                  reference).

         99.2.    Press Release, dated June 22, 2001 (filed as an exhibit to
                  ACGL's Report on Form 8-K, as filed with the Securities and
                  Exchange Commission on July 6, 2001, and incorporated by
                  reference).


                                       2
<Page>

                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934, as
amended, the registrant has duly caused this report to be signed on its behalf
by the undersigned thereunto duly authorized.


                             ARCH CAPITAL GROUP LTD.


Date:  August 7, 2001        By: /s/ Debra M. O'Connor
                                 ----------------------
                                 Debra M. O'Connor
                                 Senior Vice President, Controller and Treasurer







                                       3
<Page>


                                     ARCH CAPITAL GROUP LTD. AND SUBSIDIARIES
                                                       INDEX

<Table>
<Caption>
                                                                                                             Page
                                                                                                         -------------
                                                                                                             
FINANCIAL STATEMENTS OF BUSINESS ACQUIRED.

AUDITED CONSOLIDATED FINANCIAL STATEMENTS OF ALTUS:
Independent Auditors' Report                                                                                        5
Consolidated Balance Sheets - December 31, 2000 and 1999                                                          6-7
Consolidated Statements of Operations - Years Ended December 31, 2000 and 1999                                      8
Consolidated Statements Shareholders' Equity - Years Ended December 31, 2000 and 1999                            9-10
Consolidated Statements of Cash Flows - Years Ended December 31, 2000 and 1999                                     11
Notes to Consolidated Financial Statements - Years Ended December 31, 2000 and 1999                             12-23

UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS OF ALTUS:
Unaudited Consolidated Balance Sheet - March 31, 2001 and 2000                                                     24
Unaudited Consolidated Statement of Operations - For the Three Months Ended March 31, 2001 and 2000                25
Unaudited Consolidated Statement of Cash Flows - For the Three Months Ended March 31, 2001 and 2000                26
Notes to the Unaudited Consolidated Financial Statements - For the Three Months Ended March 31, 2001
and 2000                                                                                                           27

PRO FORMA FINANCIAL INFORMATION.

Unaudited Pro Forma Condensed Combined Financial Statements of ACGL and Altus:

Unaudited Pro Forma Condensed Combined Balance Sheet - March 31, 2001                                              29
Unaudited Pro Forma Condensed Combined Statement of Income - For the Three Months Ended March 31, 2001             30
Unaudited Pro Forma Condensed Combined Statement of Income - For the Year Ended December 31, 2000                  31
Notes to the Unaudited Pro Forma Condensed Combined Financial Statements                                        32-33

</Table>


                                       4
<Page>

ITEM 7.       FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

(a)      FINANCIAL STATEMENTS OF BUSINESS ACQUIRED.

      Audited Consolidated Financial Statements of Altus:





INDEPENDENT AUDITORS' REPORT


To the Shareholders
of Altus Holdings, Ltd.

We have audited the accompanying consolidated balance sheets of Altus Holdings,
Ltd. (the "Company") as of December 31, 2000 and 1999, and the related
consolidated statements of operations, stockholders' equity, and cash flows for
the years then ended. These consolidated financial statements are the
responsibility of the Company's management. Our responsibility is to express an
opinion on these consolidated financial statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States of America. Those standards require that we plan and
perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. An audit includes examining, on a
test basis, evidence supporting the amounts and disclosures in the financial
statements. An audit also includes assessing the accounting principles used and
significant estimates made by management, as well as evaluating the overall
financial statement presentation. We believe that our audits provide a
reasonable basis for our opinion.

In our opinion, such consolidated financial statements present fairly, in all
material respects, the financial position of the Company as of December 31, 2000
and 1999, and the results of its operations and its cash flows for the years
then ended in conformity with accounting principles generally accepted in the
United States of America.

/s/ Deloitte & Touche LLP

May 18, 2001


                                       5
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED BALANCE SHEETS
DECEMBER 31, 2000 AND 1999
(IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>

ASSETS                                                                       2000          1999
                                                                           --------      --------
                                                                                   
Investments:
  Securities available-for-sale, at fair value -
    Fixed maturities (amortized cost: 2000 - $49,868; 1999 - $46,914)      $ 50,272      $ 45,859
    Equities (cost: 1999 - $597)                                                 --           633
  Certificates of deposit                                                     3,325         1,078
                                                                           --------      --------
          Total investments                                                  53,597        47,570

Cash and cash equivalents                                                    13,204        10,576
Receivables - less allowance of $1,371 and $1,266                            17,235         4,022
Reinsurance assets:
  Paid losses and loss adjustment expenses recoverable                        2,977           989
  Unpaid losses and loss adjustment expenses recoverable                     21,874         1,924
  Prepaid reinsurance premiums                                               31,942         1,166
Deferred acquisition costs                                                    3,244         2,437
Furniture and equipment - at cost, less accumulated
  depreciation of $793 and $462                                               1,078           693
Accrued investment income                                                       815           982
Other assets                                                                    305           277
Assets held in separate accounts                                              2,552         1,057
                                                                           --------      --------
TOTAL                                                                      $148,823      $ 71,693
                                                                           ========      ========
</Table>

See notes to consolidated financial statements.


                                       6
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED BALANCE SHEETS
DECEMBER 31, 2000 AND 1999
(IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>

LIABILITIES AND SHAREHOLDERS' EQUITY                            2000            1999
                                                              ---------       ---------
                                                                        
LIABILITIES:
  Unearned premiums                                           $  47,817       $  11,934
  Losses and loss adjustment expenses                            25,505           5,092
  Claims payable                                                  2,277           1,054
  Reinsurance balances payable                                   17,239             356
  Other liabilities                                               6,907           5,110
  Liabilities related to separate accounts                        2,552           1,057
                                                              ---------       ---------
           Total liabilities                                    102,297          24,603
                                                              ---------       ---------

Commitments and contingencies

SHAREHOLDERS' EQUITY:
  Class A common shares, $.01 par value:
    Authorized: 200,000,000 Class A and B shares; issued
    and outstanding: 67,469,902 and 72,250,376                      674             722
  Class B common shares, $.01 par value: issued and
    outstanding: 1,002,000                                           10              10
  Additional paid-in capital                                     63,330          63,081
  Accumulated other comprehensive income (loss), net                295          (1,019)
  Accumulated deficit                                           (17,635)        (15,509)
  Deferred compensation                                            (148)           (195)
                                                              ---------       ---------
           Total shareholders' equity                            46,526          47,090
                                                              ---------       ---------

TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY                    $ 148,823       $  71,693
                                                              =========       =========
</Table>


See notes to consolidated financial statements.


                                       7
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED STATEMENTS OF OPERATIONS
YEARS ENDED DECEMBER 31, 2000 AND 1999
(IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>
                                                           2000           1999
                                                         --------       --------
                                                                  
REVENUES:
  Premiums earned                                        $ 19,136       $ 21,473
  Finance and service charges                                  74            214
  Commissions                                                  --            362
  Net investment income                                     3,280          3,090
  Realized gains (losses) on investments                       62           (242)
  Other                                                        --            375
                                                         --------       --------

          Total revenues                                   22,552         25,272
                                                         --------       --------
LOSSES AND EXPENSES:
  Losses and loss adjustment expenses                      10,986         12,785
  Underwriting, acquisition and insurance expenses         12,170         22,111
  Provision for bad debt                                      459            895
  Write-off of goodwill                                        --          1,887
  Loss on disposal of furniture and equipment                  --          2,299
  Corporate and other expense                               1,227            197
                                                         --------       --------
          Total losses and expenses                        24,842         40,174
                                                         --------       --------

Loss from continuing operations before income taxes        (2,290)       (14,902)
Income tax (expense) benefit                                   92           (116)
                                                         --------       --------

          Loss from continuing operations                  (2,198)       (15,018)

Gain from discontinued operations                              72            189
                                                         --------       --------

          Net loss                                       $ (2,126)      $(14,829)
                                                         ========       ========
</Table>


See notes to consolidated financial statements.


                                       8
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY
YEARS ENDED DECEMBER 31, 2000 AND 1999
(DOLLARS IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>
                                                       COMMON STOCK
                                ----------------------------------------------------------                     ACCUMULATED
                                         CLASS A                         CLASS B                ADDITIONAL        OTHER
                                --------------------------       -------------------------        PAID-IN      COMPREHENSIVE
                                  SHARES           AMOUNT          SHARES        AMOUNT           CAPITAL      INCOME (LOSS)
                                ----------      ----------       ---------      ----------      ---------       ----------
                                                                                              
BALANCE, DECEMBER 31, 1998      63,085,709      $      514       1,000,000      $       10      $   45,074      $      298

Comprehensive loss:
 Net loss
 Other comprehensive loss                                                                                           (1,317)
Comprehensive loss

Repurchase of Class A and B
  common shares                 (4,777,000)            (31)       (223,000)             (2)         (3,300)
Call on capital commitment               -             100               -                           9,900
Issuance of class A and B
  common shares                 13,941,667             139         225,000               2          14,025
Amortization of deferred
  compensation
Repurchase of FAFC shares of
  terminated officer                                                                                  (500)
Cancellation of FAFC deferred
  compensation                                                                                      (2,118)

BALANCE, DECEMBER 31, 1999      72,250,376             722       1,002,000              10          63,081          (1,019)

<Caption>

                                                                      TOTAL
                                  ACCUMULATED       DEFERRED       SHAREHOLDERS'
                                    DEFICIT        COMPENSATION       EQUITY
                                  ----------       ----------       ----------
                                                           
BALANCE, DECEMBER 31, 1998        $     (680)      $   (2,375)      $   42,841

Comprehensive loss:
 Net loss                            (14,829)                          (14,829)
 Other comprehensive loss                                               (1,317)
                                                                    ----------
Comprehensive loss                                                     (16,146)

Repurchase of Class A and B
  common shares                                                         (3,333)
Call on capital commitment                                              10,000
Issuance of class A and B
  common shares                                                         14,166
Amortization of deferred
  compensation                                             62               62
Repurchase of FAFC shares of
  terminated officer                                                      (500)
Cancellation of FAFC deferred
  compensation                                          2,118               --

BALANCE, DECEMBER 31, 1999           (15,509)            (195)          47,090

</Table>

See notes to consolidated financial statements.


                                       9
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (CONTINUED)
YEARS ENDED DECEMBER 31, 2000 AND 1999
(DOLLARS IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>
                                                                       COMMON STOCK
                                              ---------------------------------------------------------------
                                                       CLASS A                              CLASS B                ADDITIONAL
                                              ----------------------------         --------------------------       PAID-IN
                                                SHARES           AMOUNT             SHARES          AMOUNT          CAPITAL
                                              ----------       -----------         ---------      -----------      -----------
                                                                                                    
BALANCE, DECEMBER 31, 1999                    72,250,376       $       722         1,002,000      $        10      $    63,081

Comprehensive loss:
 Net loss
 Other comprehensive income

Comprehensive loss

Issuance of common stock and Warrants            193,156                 2                                                 173
Cancellation of common stock                  (5,000,000)              (50)                                                 50
Issuance of Class A common Shares award           26,370                 *                                                  26
Amortization of deferred Compensation

BALANCE, DECEMBER 31, 2000                    67,469,902       $       674         1,002,000      $        10      $    63,330
                                              ==========       ===========         =========      ===========      ===========

<Caption>
                                                  ACCUMULATED
                                                    OTHER                                                  TOTAL
                                                 COMPREHENSIVE      ACCUMULATED        DEFERRED         SHAREHOLDERS'
                                                 INCOME (LOSS)        DEFICIT        COMPENSATION         EQUITY
                                                 -------------      -----------      ------------       -----------
                                                                                            
BALANCE, DECEMBER 31, 1999                       $     (1,019)      $   (15,509)     $       (195)      $    47,090

Comprehensive loss:
 Net loss                                                                (2,126)                             (2,126)
 Other comprehensive income                             1,314                                                 1,314
                                                                                      -----------       -----------
Comprehensive loss                                                                                             (812)

Issuance of common stock and Warrants                                                                           175
Cancellation of common stock                                                                                     --
Issuance of Class A common Shares award                                                       (26)               --
Amortization of deferred Compensation                                                          73                73
                                                                                      -----------       -----------
BALANCE, DECEMBER 31, 2000                        $       295       $   (17,635)      $      (148)      $    46,526
                                                  ===========       ===========       ===========       ===========
</Table>


*   amount not shown due to rounding

See notes to consolidated financial statements.


                                       10
<Page>

ALTUS HOLDINGS, LTD.

CONSOLIDATED STATEMENTS OF CASH FLOWS
YEARS ENDED DECEMBER 31, 2000 AND 1999
(IN THOUSANDS)
- --------------------------------------------------------------------------------

<Table>
<Caption>
                                                                                    2000           1999
                                                                                  --------       --------
                                                                                           
CASH FLOWS FROM OPERATING ACTIVITIES:
  Net loss                                                                        $ (2,126)      $(14,829)
  Adjustments to reconcile net loss to net cash
    provided by (used in) operating activities:
    Depreciation, amortization and other                                               498            971
    Realized (gains) losses on investments                                             (62)           242
    Deferred income tax expense (benefit)                                             (109)           116
    Loss on disposition of furniture and equipment                                      --          2,299
    Write-off of goodwill                                                               --          1,887
    Changes in assets and liabilities:
      Receivables                                                                  (13,318)           671
      Reinsurance assets                                                           (52,714)         1,593
      Deferred policy acquisition costs                                               (807)           859
      Unearned premiums                                                             35,883         (7,579)
      Losses and loss adjustment expenses                                           20,413         (3,453)
      Claims payable                                                                 1,223             99
      Reinsurance balances payable                                                  16,883            391
      Other assets and liabilities                                                   1,936           (729)
                                                                                  --------       --------
           Net cash provided by (used in) operating activities                       7,700        (17,462)
                                                                                  --------       --------
INVESTING ACTIVITIES:
  Proceeds from securities available-for-sale, fixed
    maturities sold or matured                                                      31,870         33,270
  Proceeds from securities available-for-sale, equities                                644            494
  Purchases of securities available-for-sale, fixed maturities                     (34,782)       (34,387)
  Purchases of securities available-for-sale, equities                                  --            (64)
  Net maturities (purchases) of certificates of deposits                            (2,247)         2,455
  Proceeds from sale of furniture and equipment                                         --             39
  Purchase of furniture and equipment                                                 (732)        (1,713)
                                                                                  --------       --------
           Net cash provided by (used in) investing activities                      (5,247)            94
                                                                                  --------       --------
FINANCING ACTIVITIES:
  Issuance of common stock and capital contributions                                   175         24,166
  Payments on repurchase of common stock                                                --         (3,333)
  Proceeds from borrowings                                                              --         15,078
  Payments on borrowings                                                                --        (17,437)
  Repurchased shares of terminated officer                                              --           (500)
                                                                                  --------       --------
           Net cash provided by financing activities                                   175         17,974
                                                                                  --------       --------
Net increase in cash and cash equivalents                                            2,628            606
Cash and cash equivalents, beginning of year                                        10,576          9,970
                                                                                  --------       --------
Cash and cash equivalents, end of year                                            $ 13,204       $ 10,576
                                                                                  ========       ========

SUPPLEMENTAL DISCLOSURES:
  Interest paid                                                                   $     --       $    197
                                                                                  ========       ========
  Taxes paid                                                                      $      7       $     --
                                                                                  ========       ========
  Non-cash financing activities - Cancellation of FAFC deferred compensation      $     --       $  2,118
                                                                                  ========       ========
</Table>

                                       11
<Page>

ALTUS HOLDINGS, LTD.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
YEARS ENDED DECEMBER 31, 2000 AND 1999
- --------------------------------------------------------------------------------


1.     SIGNIFICANT ACCOUNTING POLICIES

       PRINCIPLES OF CONSOLIDATION AND NATURE OF OPERATIONS - The accompanying
       consolidated financial statements include the accounts and operations of
       Altus Holdings, Ltd. ("Altus"), a corporation organized in the Cayman
       Islands, and its wholly owned subsidiaries (the "Company").

       During 1999, Altus acquired First American Financial Corporation
       ("FAFC"), a Missouri corporation through an exchange of shares. The
       acquisition has been accounted for as a pooling of interests under
       accounting principles generally accepted in the United States of America
       ("U.S. GAAP"). Under pooling of interests accounting, it is assumed that
       Altus and FAFC have been merged from the date of incorporation of the
       Company.

       Altus and its wholly owned subsidiaries, Alternative Re Holdings Limited
       ("ARHL"), Alternative Re Limited ("ARL"), Alternative Insurance Company
       Limited ("AICL"), Altrisc Services, Inc. ("ASI") and Alternative
       Underwriting Services ("AUS") provide insurance, reinsurance, and
       alternative reinsurance solutions through rent a captive and other
       facilities.

       FAFC and its wholly owned subsidiaries, First American Insurance Agency,
       Inc. ("FAIA"), American First Insurance Agency II, Inc., First American
       Service Corporation, First American Warranty Corporation of Florida and
       First American Insurance Company ("FAIC") and its subsidiary, First
       American General Agency, Inc. ("FAGA"), underwrite program business,
       which is comprised primarily of insurance products for lending
       institutions, workers compensation, commercial auto, personal auto and
       general liability. FAFC's products are distributed through general
       agents.

       All significant intercompany accounts and transactions have been
       eliminated in consolidation.

       BASIS OF PRESENTATION - The accompanying consolidated financial
       statements have been prepared in accordance with U.S. GAAP. The
       significant accounting policies followed by the Company that materially
       affect financial reporting are summarized in this note. They include the
       acquisition of FAFC, which occurred in July 1999, and which has been
       accounted for as a pooling of interests under U.S. GAAP. The consolidated
       financial statements include FAFC as though it had always been a part of
       the Company.

       USE OF ESTIMATES - The preparation of consolidated financial statements
       of insurance companies requires management to make estimates and
       assumptions that affect amounts reported in the consolidated financial
       statements and accompanying notes. Such estimates and assumptions could
       change in the future, as more information becomes known that could impact
       the amounts reported and disclosed therein.

       INVESTMENTS - Investment securities are classified as held-to-maturity,
       available-for-sale or trading. Currently, all of the Company's securities
       are classified as available-for-sale. Securities classified as
       available-for-sale are carried at fair value, and changes in fair value,
       net of deferred income taxes, are reported as a component of accumulated
       other comprehensive income or loss and, accordingly, have no effect on
       the Company's net loss. Fair values for fixed maturities and equities
       (see Note 3) are based on quoted market prices. Certificates of deposit
       are reported at cost, which approximates fair value.


                                       12
<Page>

       The amortized cost of fixed maturities classified as available-for-sale
       or held-to-maturity is adjusted for amortization of premiums and
       accretion of discounts to maturity. Such amortization is included in net
       investment income. Realized gains and losses on sales of investments and
       declines in value judged to be other-than-temporary are recognized on the
       specific identification basis.

       PREMIUMS - Premiums are recognized as revenue principally pro rata over
       the terms of the policies. Certain warranty premiums are earned based on
       exposure patterns that increase over time. In addition, GAP premiums,
       which cover the difference between automobile loan values and underlying
       collateral, are earned in an accelerated manner based on a modified rule
       of 78ths method to reflect the increased initial exposure on these
       policies.

       DEFERRED ACQUISITION COSTS - Acquisition costs consisting of commissions,
       premium taxes and other underwriting expenses are deferred and amortized
       ratably over the term of the related policies. The method followed in
       computing deferred acquisition costs limits the amount of such costs to
       their expected realizable value. In determining expected realizable
       value, the computation gives effect to the premium to be earned, related
       investment income, losses, loss adjustment expenses and certain other
       costs expected to be incurred as the premium is earned.

       LOSSES AND LOSS ADJUSTMENT EXPENSES - Losses and loss adjustment expenses
       represent the estimated ultimate net cost of all reported and unreported
       losses incurred and are estimated using case-basis evaluations and
       statistical analyses, and are not discounted. Those estimates are subject
       to the effects of trends in loss severity and frequency, and variability
       is inherent in such estimates. Changes in estimates are reflected in
       current operations.

       REINSURANCE - Reinsurance premiums and losses and loss adjustment
       expenses recoverable are accounted for on bases consistent with those
       used in accounting for the original policies issued and the terms of the
       reinsurance contracts. The accompanying consolidated statements of
       operations reflect premiums, losses and loss adjustment expenses, and
       acquisition costs, net of reinsurance ceded (see Note 5). Those
       reinsurance arrangements provide for greater diversification of business,
       allow management to control exposure to potential losses arising from
       large risks and provide additional capacity for growth. The Company uses
       quota-share, surplus share and excess-of-loss reinsurance contracts.

       FAIR VALUE OF FINANCIAL INSTRUMENTS - The estimated fair value of
       financial instruments held by the Company approximates carrying value.

       EXCESS OF COST OVER NET TANGIBLE ASSETS ACQUIRED - In 1999 management
       reevaluated the carrying value of goodwill within the requirements of
       SFAS No. 121, "ACCOUNTING FOR IMPAIRMENT OF LONG-LIVED ASSETS AND
       LONG-LIVED ASSETS TO BE DISPOSED OF," and determined that it no longer
       had any value. As such, management reduced the carrying value of all
       goodwill to zero. The result was a loss of $1,887,000 recorded in the
       statement of operations in 1999.

       STATEMENTS OF CASH FLOWS - Cash and cash equivalents in the consolidated
       statements of cash flows represent cash balances and investments with
       initial maturities of three months or less.

       COMMISSION INCOME - The Company's active insurance agencies, ASI, FAIA
       and FAGA, record commissions as income when the related policies are
       written.

       INCOME TAXES - U.S. deferred taxes are determined based on the
       differences between the financial reporting and tax bases of assets and
       liabilities and are measured using enacted tax rates.


                                       13
<Page>

       Under current Cayman Islands law, Altus is not required to pay taxes in
       the Cayman Islands on either income or capital gains. Altus has received
       an undertaking from the Cayman Islands government that, in the event of
       income or capital gains taxes being imposed, the Company will be exempted
       from such taxes until the year 2018.

       Under current Bermuda law, ARHL, ARL, AICL, and AUS are not required to
       pay taxes in Bermuda on either income or capital gains. They have
       received an undertaking from the Bermuda government that, in the event of
       income or capital gains taxes being imposed, they will be exempted from
       such taxes until the year 2016.

       AICL has made the election under Internal Revenue Code Section 953(d) to
       be subject to U.S. income taxes as a domestic U.S. insurance company.
       AICL and ASI file separate U.S. federal income tax returns. FAFC files a
       consolidated U.S. federal income tax return.

       FURNITURE AND EQUIPMENT - Furniture and equipment are recorded at cost
       and are depreciated using the straight-line method over three to five
       years.

       SEPARATE ACCOUNTS - Under rent a captive arrangement, ARL maintains
       segregated cells in separate accounts for companies ("Program Holders"),
       whereby the Program Holder assumes investment, underwriting and exposure
       risk and ARL receives an administration fee for managing the program. The
       Program Holder owns preferred shares in ARHL under a Preferred
       Shareholders Agreement ("the Agreement"). The Agreement provides for the
       payment of dividends to the preferred shareholders based on the balance
       of net profits calculated from earned reinsurance premiums, investment
       income, expenses paid and losses and loss adjustment expenses incurred in
       each Program Holder's account. Any profits are to be paid to the
       preferred shareholders based upon a percentage of total profits to date,
       calculated on an annual basis, commencing after the third year of the
       Agreement. If the balance is a deficit at any time, additional letters of
       credit, cash or indemnifications will be due to ARL. The preferred shares
       are redeemable after five years. AICL is also permitted to maintain
       segregated cells.

       ACCOUNTING PRONOUNCEMENT - The Company adopted Statement of Financial
       Accounting Standards ("SFAS") No. 133, "Accounting for Derivative
       Instruments and Hedging Activities" in 2001. The Company does not engage
       in hedging activities or invest in derivative instruments, including
       derivatives embedded in other contracts. Accordingly, adoption of SFAS
       No. 133 did not affect the financial statements.

       RECLASSIFICATIONS - Certain 1999 amounts have been reclassified to
       conform to the 2000 presentation.

2.     BUSINESS COMBINATION

       On June 18, 1999, Altus acquired FAFC in an all-stock transaction.
       Shareholders of FAFC (the Trident Partnership, L.P. ("Trident") and Risk
       Capital Reinsurance Company ("Risk Capital") (which, in May, 2000 was
       renamed Arch Reinsurance Company) received 28,780,476 newly issued Class
       A common shares. Trident was and remains a majority shareholder in Altus
       and was also a majority shareholder in FAFC. In connection with the
       acquisition by Altus, FAFC received a capital infusion of $28,000,000.
       Also as a result of the purchase, all Class A, $7 par, common stock of
       FAFC was retired and 1,000 shares of Class A, $.10 par, common stock was
       reissued to Altus. Proceeds from the capital infusion were used to make a
       capital contribution of $15,000,000 to FAIC and to repay note borrowings
       of $11,000,000. The remaining proceeds of $2,000,000 were retained by
       FAFC for internal operating and investing purposes. The transaction has
       been accounted for as a pooling of interest under U.S. GAAP. No
       adjustments were necessary to conform FAFC's accounting policies.


                                       14
<Page>

       The following table presents the revenues and loss for the combining
       companies and subsidiaries for the period from the beginning of 1999 to
       the date the acquisition was consummated (in thousands): All significant
       intercompany transactions have been eliminated.

                                             ALTUS          FAFC

               Revenues                     $  167         $ 6,334
               Loss                         $ (903)        $(2,675)


       A post closing adjustment to the acquisition related to losses required
       that effective December 31, 1999 up to 5,000,000 of the Company's Class A
       common shares issued as part of the acquisition be cancelled on a pro
       rata basis between the individual shareholders. One Class A common share
       of the Company was cancelled for every $1 of defined losses subject to a
       $5,000,000 maximum.

       Defined losses were the sum of the operating losses or expenses incurred
       or reserved during the period from April 1, 1999 to December 31, 1999
       primarily related to portions of FAIC's cancelled or exited business.
       These losses exceeded $5,000,000, and therefore 5,000,000 Class A common
       shares were cancelled in 2000 on a pro rata basis between the individual
       shareholders and the related par value of $50,000 was transferred to
       additional paid-in-capital.

3.     INVESTMENTS

       Investments are summarized as follows (in thousands):

<Table>
<Caption>
                                          COST/        GROSS       GROSS
                                        AMORTIZED    UNREALIZED   UNREALIZED     FAIR
                                          COST         GAINS       LOSSES        VALUE
                                        ---------    ---------    ----------    -------
                                                                    
       December 31, 2000:
         U.S. government bonds           $34,741      $   236      $    79      $34,898
         Industrial bonds                 10,648          184           85       10,747
         U.S. mortgage backed bonds        4,479          148           --        4,627
                                         -------      -------      -------      -------
       Total fixed maturities            $49,868      $   568      $   164      $50,272
                                         =======      =======      =======      =======

<Caption>

                                          COST/        GROSS       GROSS
                                        AMORTIZED    UNREALIZED   UNREALIZED     FAIR
                                          COST         GAINS       LOSSES        VALUE
                                        ---------    ---------    ----------    -------
                                                                    
       December 31, 1999:
         U.S. government bonds           $43,326      $     7      $   814      $42,519
         Industrial bonds                  3,146           --          245        2,901
         U.S. mortgage backed bonds          442           --            3          439
                                         -------      -------      -------      -------
       Total fixed maturities             46,914            7        1,062       45,859
       Equities                              597           36           --          633
                                         -------      -------      -------      -------
                                         $47,511      $    43      $ 1,062      $46,492
                                         =======      =======      =======      =======
</Table>


                                       15
<Page>

       The following amounts were included in accumulated other comprehensive
       income (loss) for the years ended December 31, 2000 and 1999 (in
       thousands):

<Table>
<Caption>
                                                                        2000         1999
                                                                      -------      -------
                                                                             
       Unrealized holding gains (losses) arising during the year      $ 1,485      $(1,671)
       Less realized gains (losses)                                        62         (242)
                                                                      -------      -------

       Other comprehensive (loss) income, before deferred taxes         1,423       (1,429)
       Deferred income tax (expense) benefit                             (109)         118
       Other                                                               --           (6)
                                                                      -------      -------
       Other comprehensive income (loss), net                         $ 1,314      $(1,317)
                                                                      =======      =======
</Table>

       Contractual maturities of fixed maturities at December 31, 2000 are
       summarized as follows (in thousands):

<Table>
<Caption>
                                                   AMORTIZED       FAIR
                                                     COST          VALUE
                                                   ---------      -------
                                                            
       Due within one year                          $13,081       $13,124
       Due after one through five years              25,155        25,237
       Due after five through ten years              11,156        11,424
       Due after ten years                              476           487
                                                    -------       -------
                                                    $49,868       $50,272
                                                    =======       =======
</Table>

       The expected maturities in the foregoing table will differ from
       contractual maturities because certain issuers may have the right to call
       or prepay obligations with or without call or prepayment penalties.

       Major sources of the Company's investment income are summarized as
       follows (in thousands):

<Table>
<Caption>
                                                                 2000           1999
                                                                -------       -------
                                                                        
       Fixed maturities                                         $ 3,024       $ 2,460
       Equities                                                      --            63
       Certificates of deposit and other                            346           675
                                                                -------       -------
                                                                  3,370         3,198
       Investment expenses                                          (90)          (54)
                                                                -------       -------
       Net investment income                                      3,280         3,144
       Less investment income from discontinued operations           --           (54)
                                                                -------       -------
       Net investment income from continuing operations         $ 3,280       $ 3,090
                                                                =======       =======
</Table>

                                       16
<Page>

       Proceeds from the sale of equity securities were $645,000 and $494,000 in
       2000 and 1999, respectively. The Company had gross realized gains of
       $47,000 in 2000 and gross realized losses of $61,000 in 1999 on those
       sales.

       Proceeds from sales, maturities and redemptions of investments in bonds
       during 2000 and 1999 were $31,869,000 and $33,270,000, respectively. In
       2000 and 1999, the Company had gross realized gains of $162,000 and
       $36,000, respectively and gross realized losses of $147,000 and $217,000,
       respectively.

       At December 31, 2000, cash and cash equivalents of $646,000 and fixed
       maturity securities with a carrying amount of $5,325,000 were on deposit
       with state insurance departments to satisfy regulatory requirements. Also
       at December 31, 2000, fixed maturity securities and cash and cash
       equivalents with a carrying amount of $3,784,000 and $254,000,
       respectively, were on deposit in various trusts securing unearned premium
       reserves and loss reserves on insurance assumed from other companies.

4.     INCOME TAXES

       For financial reporting purposes, loss from continuing operations before
       income taxes includes the following components (in thousands):

<Table>
<Caption>
                                                        2000           1999
                                                      --------       --------
                                                               
       Income (loss) from continuing operations:
          United States                               $ (2,442)      $(11,935)
          Puerto Rico                                      392         (2,545)
          Other countries                                 (240)          (422)
                                                      --------       --------
                                                      $ (2,290)      $(14,902)
                                                      ========       ========
</Table>

       The components of income tax (expense) benefit are as follows (in
       thousands):

<Table>
<Caption>
                                                   2000            1999
                                                  -----            -----
                                                             
       Current - Federal                            (10)               2
       Current - State                               (7)              --
       Deferred - Federal                           109             (118)
                                                  -----            -----
                                                  $  92            $(116)
                                                  =====            =====
</Table>

       U.S. deferred income taxes at December 31 consist of the following
       amounts (in thousands):

<Table>
<Caption>
                                                 2000             1999
                                               --------         --------
                                                          
       Deferred tax asset                      $ 10,877         $  9,896
       Deferred tax liability                    (1,220)            (859)
       Valuation allowance                       (9,657)          (9,037)
                                               --------         --------
       Net deferred tax asset                  $     --         $     --
                                               ========         ========
</Table>

                                       17
<Page>

       The deferred tax asset relates principally to net operating loss ("NOL")
       carryforwards, alternative minimum tax ("AMT") credit carryforwards,
       unearned premium reserves, loss reserve discounting and depreciation
       expense. The deferred tax liability relates principally to deferred
       policy acquisition costs. The Company maintains a full valuation
       allowance in respect of the net deferred tax asset since it is more
       likely than not that the benefit will not be utilized.

       The income tax benefit in 2000 and expense in 1999 is not proportional to
       loss before federal income taxes principally due to the change in the
       valuation allowance, as discussed above.

       FAFC has NOL carryforwards of $20,442,000 that expire beginning in 2011
       and an AMT credit carryforward of $307,000 that has an unlimited
       carryforward period. ASI has NOL carryforwards of $4,334,000 that expire
       beginning in 2012. AICL has an AMT credit carryforward of $7,000.

5.     REINSURANCE

       Premiums written and earned are summarized as follows (in thousands):

<Table>
<Caption>
                                         2000                         1999
                                WRITTEN        EARNED         WRITTEN        EARNED
                               --------       --------       --------       --------
                                                                
       Direct and assumed      $ 87,571       $ 51,685       $ 16,265       $ 23,844
       Ceded                    (63,328)       (32,549)        (2,156)        (2,371)
                               --------       --------       --------       --------
       Net premiums            $ 24,243       $ 19,136       $ 14,109       $ 21,473
                               ========       ========       ========       ========
</Table>

       Losses and loss adjustment expenses are summarized as follows (in
       thousands):

<Table>
<Caption>
                                                                             2000           1999
                                                                           --------       --------
                                                                                    
       Direct and assumed                                                  $ 38,724       $ 14,333
       Ceded                                                                (27,810)        (1,682)
                                                                           --------       --------

       Total losses and loss adjustment expenses                             10,914         12,651
       Decrease in losses and loss adjustment expenses
         from discontinued operations                                            72            134
                                                                           --------       --------
       Losses and loss adjustment expenses from continuing operations      $ 10,986       $ 12,785
                                                                           ========       ========
</Table>

       Reinsurance ceded contracts do not relieve the Company from its
       obligations to policyholders. In the unlikely event that any reinsurer
       does not meet its obligations under the reinsurance agreements, the
       Company remains liable to its policyholders for the portion reinsured. At
       December 31, 2000 and 1999, all amounts recoverable by FAIC under
       agreements with unauthorized reinsurers are fully secured by letters of
       credit, except for $463,000 and $113,000 of unsecured balances at those
       respective dates.

                                       18
<Page>

6.    FURNITURE AND EQUIPMENT

       Furniture and equipment are summarized as follows (in thousands):

<Table>
<Caption>
                                                    2000            1999
                                                   ------          ------
                                                             
       Furniture and fixtures                      $  497          $  660
       Information systems                            581              33
                                                   ------          ------
                                                   $1,078          $  693
                                                   ======          ======
</Table>

7.     LOSSES AND LOSS ADJUSTMENT EXPENSES

       The following table provides a reconciliation of the beginning and ending
       reserve balances, net of reinsurance, for the years ended December 31 (in
       thousands):

<Table>
<Caption>
                                                                               2000           1999
                                                                             --------       --------
                                                                                      
       Reserve for losses and loss adjustment expenses ("LAE"), net of
         reinsurance, at January 1                                           $  3,168       $  4,821
                                                                             --------       --------
       Add incurred related to:
         Current year                                                          11,178         13,167
         Prior years                                                             (192)          (516)
                                                                             --------       --------
       Total incurred                                                          10,986         12,651
                                                                             --------       --------
       Deduct paid related to:
         Current year                                                           8,292         10,373
         Prior years                                                            2,231          3,931
                                                                             --------       --------
       Total paid                                                              10,523         14,304
                                                                             --------       --------
       Reserve for losses and LAE, net of reinsurance, at December 31           3,631          3,168
       Reinsurance recoverable on unpaid losses and LAE, at December 31        21,874          1,924
                                                                             --------       --------
       Reserve for unpaid losses and LAE, gross of reinsurance, at
         December 31                                                         $ 25,505       $  5,092
                                                                             ========       ========
</Table>

       The incurred amounts for prior years' claims relate to changes in
       estimates of loss reserves. Such amounts are the result of using
       actuarial data and other information in establishing loss reserves and
       will vary from year to year.

                                       19
<Page>

8.     SHARE CAPITAL

       On March 19, 1998, warrants to purchase a total of 3,500,000 shares of
       the Company's Class A common shares at $1.00 per share were issued to
       certain shareholders. These warrants are exercisable immediately, and
       include 3,000,000 that expire on March 19, 2008. The 500,000 balance of
       warrants were redistributed among certain shareholders and expire on
       March 5, 2008. During 2000, warrants on 7,500 Class A common shares
       expiring on December 29, 2010 were purchased by a senior executive
       officer. Together with warrants discussed in Note 9, warrants for
       3,538,023 and 3,530,523 were outstanding at December 31, 2000 and 1999,
       respectively.

       In the event that the Company enters into an initial public offering, or
       a change in control, these warrants are callable by the Company, in their
       entirety, or partially. The Company can redeem these warrants for $.01
       each. Any partial redemption by the Company will be made on a pro rata
       basis on the total outstanding warrants at the time of redemption.

       See Note 18 - Subsequent Event.

9.     STOCK COMPENSATION

       The Company has elected to follow Accounting Principles Board ("APB")
       Opinion No. 25, "ACCOUNTING FOR STOCK ISSUED TO EMPLOYEES," in accounting
       for its employee stock awards, employee stock options and stock
       appreciation rights.

       Pursuant to APB Opinion No. 25, compensation expense for stock awards,
       options and grants is recognized as follows: (1) nonperformance awards -
       measured at the fair value of the shares at the date of grant and
       recognized as the awards vest; (2) performance-based stock awards and
       stock options - periodically remeasured based on the fair value of the
       stock and recognized only when it is probable that an amount will be
       earned; and (3) stock options - recognized only if the exercise price of
       the stock options is below the market price of the underlying stock on
       the date of grant.

       1998 STOCK OPTION PLAN - During 1998, the Company adopted the Management
       Share Option Plan (the "Plan"), which permits the Board of Directors of
       the Company to grant stock options to employees, officers and directors
       of the Company. A total of 2,543,605 shares were authorized under the
       Plan. Generally, the Company grants stock options with an exercise price
       equal to the fair market value of the common share on the date of the
       grant, as determined by the Company's Board of Directors. Stock options
       generally vest ratably over a five-year period, and expire in March 2008.
       Options to purchase 300,000 and 450,000 Class A common shares were
       granted for $1.00 per share in 2000 and 1999, respectively. No options
       were exercised in 2000 or 1999. Options forfeited or cancelled totaled
       250,000 and nil in 2000 and 1999, respectively. At December 31, 2000 and
       1999, options outstanding totaled 2,072,674 and 2,022,674, respectively,
       of which 1,048,449 and 524,225, respectively were vested.

       WARRANT AWARDS - During 1998, in consideration for entering into an
       employment agreement with the Company, a senior executive of the Company
       was granted warrants to purchase 30,523 Class A common shares for $1.00
       per share. These warrants are exercisable by the holder from March 19,
       1998 until they expire on March 19, 2008. These warrants are subject to
       the same terms and conditions as the 1998 Stock Option Plan discussed
       previously in this note.


                                       20
<Page>

       1998 AND 1999 STOCK AWARDS - During 1998, the Company entered into an
       employment agreement with a senior executive that provided for stock
       awards. Nonperformance awards for 305,233 Class A common shares under a
       restricted share grant were granted to the senior executive. The shares
       vest equally over a five-year period. In addition, as part of the
       acquisition of FAFC, 26,370 non-performance common shares were awarded to
       an officer. These shares vest equally over three years. The Company has
       charged expenses of $73,000 and $62,000 in 2000 and 1999, respectively,
       relating to compensation on these restricted share grants.

       During 1999, the Company entered into a consulting agreement with a
       senior non-executive that provided for stock options. The individual
       agreed to purchase 250,000 Class A common shares for $1.00 per share by
       January 1, 2001. Pursuant to this purchase, options to purchase by
       January 1, 2001, 750,000 Class A common shares were granted for $1.00 per
       share, under the same terms and conditions as the Plan. The
       aforementioned purchase did not occur and, accordingly, the related
       options were forfeited.

       See Note 18 - Subsequent Event.

       Certain performance-based stock awards and stock options issued in
       conjunction with investments in FAFC by Trident and Risk Capital were
       cancelled in 1999 as part of the acquisition of FAFC by the Company.

       PRO FORMA NET INCOME - Pro forma information regarding net income is
       required by SFAS No. 123, "ACCOUNTING FOR STOCK-BASED COMPENSATION," as
       if the Company had accounted for its employee stock options, stock
       warrants, and stock awards under the fair value method of that statement.
       Had compensation cost for the Company's employee stock options, stock
       warrants, and stock awards been determined based upon the fair value, as
       determined by the board of directors, at the grant date for awards under
       these plans consistent with the methodology prescribed under SFAS No.
       123, the Company's loss for the years ended December 31, 2000 and 1999
       would have been as follows (in thousands):

<Table>
<Caption>
                                                    2000           1999
                                                   -------        -------
                                                            
       Net loss as reported                        $ 2,126        $14,829
                                                   =======        =======

       SFAS No. 123 proforma loss                  $ 2,229        $15,080
                                                   =======        =======
</Table>

       The Black-Scholes Option Pricing Model was used to estimate the fair
       values of options granted during 2000 and 1999. The assumptions used for
       these grants included the following:

       Volatility factor of expected market price of the
         Company's shares                                         0%
       Dividend yield                                             0%
       Weighted average expected life of stock options      10 years
       Risk free interest rate                                    6%

10.    CREDIT AGREEMENTS

       As part of the acquisition of FAFC by Altus, all outstanding debt was
       repaid in 1999 and an existing line-of-credit was cancelled. No debt was
       outstanding at December 31, 2000 and 1999.


                                       21
<Page>

11.    RESTRUCTURING

       During 1999, FAFC restructured its operations, which resulted in a charge
       of $2,227,000 consisting of severance costs, lease termination penalties
       and moving expenses. These expenses are included in underwriting,
       acquisition and insurance expenses in the consolidated statement of
       operations. Additionally, FAFC wrote off $2,299,000 of assets primarily
       related to information systems as a result of the restructuring. The
       restructuring was a result of the acquisition.

12.    CANCELLATION OF BUSINESS

       Prior to August 31, 1999 FAIC wrote vendors' single interest insurance
       policies in Puerto Rico through the Jose Baldrich Jr. Inc. Agency (the
       "Agency"). The Agency was FAIC's exclusive agency for business in Puerto
       Rico. FAIC granted the Agency processing, claims adjudication and claims
       payment authority as it related to these policies.

       FAIC ceased writing business in Puerto Rico and cancelled all business in
       effect as of August 31, 1999. An unrelated domestic insurance company
       already doing business in Puerto Rico rewrote this in force business.
       Unearned premiums refunded due to the cancellation, net of agent
       commissions, totaled $7,857,000. In addition, FAIC made a final
       termination payment to the agent of $463,000 in 1999.

13.    DISCONTINUED OPERATIONS

       In October 1995, FAIC adopted a plan to dispose of its commercial auto
       line of business. Accordingly, the consolidated financial statements
       report separately the operating results of this line of business, which
       is treated as a discontinued operation. There was no gain or loss
       associated with the disposal of this business.

       A summary of balances and operating results of the discontinued
       operations for the years ended December 31 is as follows (in thousands):

<Table>
<Caption>
                                                               2000          1999
                                                             -------       -------
                                                                     
       Reserve for losses and loss adjustment expenses:
         Direct                                              $ 1,423       $ 1,960
         Ceded                                                (1,019)       (1,417)
       Investment income                                          --            54
       Gain                                                       72           189
</Table>

14.    STATUTORY AND REGULATORY MATTERS

       The Company's ability to pay dividends is subject to certain regulatory
       restrictions on the payment of dividends by ARL, AICL and FAIC.

       Under the Insurance Act 1978 of Bermuda, amendments thereto and related
       regulations, ARL and AICL are required to maintain certain measures of
       solvency and liquidity. At December 31, 2000 these requirements were met.
       Declaration of dividends from retained earnings and distributions from
       additional paid-in-capital is subject to these requirements being met.

       As of December 31, 2000, FAIC had statutory capital and surplus of
       $36,478,000 and statutory net income of $727,000 for the year then ended.
       Payment of dividends by FAIC to the Company, its ultimate parent, is
       limited to the lesser of 10% of surplus or 100% of net investment income.
       At December 31, 2000, FAIC can pay $2,679,000 in dividends to FAFC
       without prior approval of the Missouri Department of Insurance ("MDI").


                                       22
<Page>

       FAIC's statutory-basis financial statements are prepared in accordance
       with accounting practices prescribed or permitted by MDI. In 1998, the
       National Association of Insurance Commissioners adopted codified
       statutory accounting principles ("Codification"). Codification will
       change, to some extent, prescribed statutory accounting practices. The
       State of Missouri adopted Codification as the prescribed basis of
       accounting on which domestic insurers must report their statutory-basis
       results to MDI, effective the first quarter of 2001. Adoption of
       Codification in the first quarter of 2001 did not have a material effect
       on FAIC's statutory surplus or statutory net income.

15.    BENEFIT PLANS

       ASI has a 401(k) plan for which substantially all employees are eligible.
       ASI's contributions to the plan were $101,000 and $50,000 during 2000 and
       1999, respectively. ASI also has a deferred compensation plan. ASI's
       contributions to the plan were $25,000 in 2000 and nil in 1999. Effective
       January 1, 2001 the ASI 401(k) plan was renamed the ASI/FAFC 401(k). All
       employees of FAFC are eligible to join the plan.

       Through December 31, 2000, FAFC had a defined benefit plan for which
       substantially all employees were eligible. FAFC's contributions to the
       plan were $31,000 and $46,000 during 2000 and 1999, respectively. The
       plan was terminated on December 31, 2000.

       FAFC also had an employee stock ownership plan for which all shares in
       the plan were sold when Altus purchased FAFC. The plan assets consist
       entirely of cash. No contributions were made to the plan during 2000 and
       1999. The plan terminated on December 31, 2000.

16.    LEASE COMMITMENTS

       The Company and its subsidiaries lease building space and certain office
       equipment under noncancellable leases. Future minimum payments for these
       leases are: 2001 - $422,000; 2002 - $382,000; 2003 - $175,000 and 2004
       and later years - $80,000. The Company entered into an assignment
       agreement with an unrelated company effective January 1, 2000 with
       respect to certain of its leases. Payment of the lease expenses by the
       unrelated company will reduce the payments for 2001 by $68,000. Total
       rent expense was $428,000 and $725,000 for 2000 and 1999, respectively.

17.    CONTINGENCIES

       The Company is subject to litigation of disputes in the normal course of
       its business. Management does not believe that any pending litigation or
       arbitration to which it is a party, or of which any of its assets are
       subject, is likely to have a material adverse effect on its current
       financial position or results of operations.

18.    SUBSEQUENT EVENT

       On March 23, 2001, Arch Capital Group Ltd., ("Arch Capital") (formerly
       Risk Capital Holdings, Inc.) announced that it had entered into a
       definitive agreement to acquire all of the capital stock of the Company.
       Arch Capital is a Bermuda-based diversified financial services holding
       company with an emphasis on the insurance sector. Arch Capital is a
       publicly held company listed on the NASDAQ Exchange and currently owns a
       minority interest in the Company.

       Upon closing, all warrants and stock options on the Company's common
       shares will be permanently cancelled and retired.


                                       23
<Page>

ITEM 7.  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

(a) FINANCIAL STATEMENTS OF BUSINESS ACQUIRED.

    Unaudited Consolidated Financial Statements of Altus:


ALTUS HOLDINGS, LTD.
UNAUDITED CONSOLIDATED BALANCE SHEETS
(IN THOUSANDS)

<Table>
<Caption>
                                                               MARCH 31,
                                                        ------------------------
                                                          2001            2000
                                                        --------        --------
                                                                  
ASSETS
Investments:
Fixed maturities                                        $ 56,197        $ 47,614
Equities                                                                     620
Short-term investments                                       525             567
                                                        --------        --------
Total investments                                         56,722          48,801
                                                        --------        --------

Cash                                                       7,864          10,257
Accrued investment income                                    688             588
Premiums receivable                                       15,461           3,975
Unpaid losses and loss expenses recoverable               33,147           2,460
Prepaid reinsurance premiums                              31,777           5,867
Reinsurance balances receivable                            3,153             358
Deferred policy acquisition costs                          2,505           2,397
Other assets                                               3,945           2,798
                                                        --------        --------
TOTAL ASSETS                                            $155,262        $ 77,501
                                                        ========        ========

LIABILITIES
Claims and claims expenses                              $ 37,585        $  5,757
Unearned premiums                                         46,378          16,298
Reinsurance balances payable                              15,855           3,447
Other liabilities                                          9,038           5,865
                                                        --------        --------
TOTAL LIABILITIES                                        108,856          31,367
                                                        --------        --------

SHAREHOLDERS' EQUITY                                      46,406          46,134

                                                        --------        --------
TOTAL LIABILITIES & SHAREHOLDERS' EQUITY                $155,262        $ 77,501
                                                        ========        ========
</Table>

          See notes to the unaudited consolidated financial statements.

                                       24
<Page>

ALTUS HOLDINGS, LTD.
UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS
 (IN THOUSANDS)

<Table>
<Caption>
                                                      FOR THE THREE MONTHS ENDED
                                                              MARCH 31,
                                                      -------------------------
                                                        2001              2000
                                                      -------           -------
                                                                  
REVENUES
Net premiums written                                  $ 4,495           $ 3,854
Decrease in unearned premiums                           1,274               340
                                                      -------           -------
Net premiums earned                                     5,769             4,194
Net investment income                                     973               766
Net investment gains (losses)                             279               (24)
Fee income                                              1,078               194
                                                      -------           -------
Total revenues                                          8,099             5,130
                                                      -------           -------

OPERATING COSTS AND EXPENSES
Claims and claims expenses                              4,637             2,287
Commissions and brokerage                               2,024             1,412
Other operating expenses                                2,145             2,383
                                                      -------           -------
Total operating costs and expenses                      8,806             6,082
                                                      -------           -------

Income (Loss) Before Income Taxes                        (707)             (952)
                                                      -------           -------

Income taxes:
Current
Deferred                                                 (178)
                                                      -------           -------
Income tax expense (benefit)                             (178)                0
                                                      -------           -------

Net Income (Loss)                                     ($  529)          ($  952)
                                                      =======           =======
</Table>

          See notes to the unaudited consolidated financial statements.


                                       25
<Page>

ALTUS HOLDINGS, LTD.
UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS
 (IN THOUSANDS)

<Table>
<Caption>
                                                           FOR THE THREE MONTHS ENDED
                                                                   MARCH 31,
                                                            -----------------------
                                                              2001           2000
                                                            --------       --------
                                                                      
OPERATING ACTIVITIES
Net income (loss)                                            $  (529)       $  (952)
Adjustments to reconcile net income (loss) to net cash
  provided by (used for) operating activities:
  Unpaid claims and claims expenses                           12,080            664
  Unearned premiums                                           (1,439)         4,362
  Premiums receivable                                          1,586           (807)
  Accrued investment income                                      127            394
  Prepaid reinsurance premiums                                   165         (4,703)
  Reinsurance balances recoverable                           (11,449)            95
  Reinsurance balances payable                                (1,384)         2,844
  Deferred policy acquisition costs                              739             41
  Net realized investment (gains)/losses                        (230)            25
  Other liabilities                                           (2,696)          (683)
  Other items, net                                                39           (365)
                                                            --------       --------
NET CASH PROVIDED BY (USED FOR) OPERATING ACTIVITIES          (2,991)           915
                                                            --------       --------
INVESTING ACTIVITIES
Investment activity, net                                      (2,296)        (1,207)
Property and equipment activity, net                             (53)          (105)
                                                            --------       --------

NET CASH PROVIDED BY (USED FOR) INVESTING ACTIVITIES          (2,349)        (1,312)
                                                            --------       --------

NET CASH PROVIDED BY (USED FOR) FINANCING ACTIVITIES               0              0
                                                            --------       --------

Increase (decrease) in cash                                   (5,340)          (397)
Cash beginning of period                                      13,204         10,654
                                                            --------       --------
Cash end of period                                          $  7,864       $ 10,257
                                                            ========       ========
</Table>

          See notes to the unaudited consolidated financial statements.

                                       26
<Page>

ALTUS HOLDINGS, LTD.
NOTES TO THE UNAUDITED CONSOLIDATED FINANCIAL STATEMENTS


(1)    The consolidated financial statements have been prepared by Altus
       Holdings, Ltd. ("Altus") without audit, in accordance with generally
       accepted accounting principles and pursuant to the rules and regulations
       of the Securities and Exchange Commission. In the opinion of the
       management of Altus, the accompanying financial statements include all
       adjustments which are necessary for a fair presentation of the results
       for the interim periods presented, such adjustments being of a normal
       recurring nature. Certain information and footnote disclosures have been
       condensed or omitted pursuant to such rules and regulations. It is
       suggested that these consolidated financial statements and the notes
       thereto be read in conjunction with the financial statements and notes
       thereto of Altus as of December 31, 2000 and 1999 and for the years then
       ended included in this Form 8-K/A. Results of operations in interim
       periods are not necessarily indicative of results to be expected for a
       full year.

(2)    On June 22, 2001, Arch Capital Group Ltd. ("ACGL") acquired all of the
       capital stock of Altus that it did not already own, pursuant to the
       Reorganization Agreement dated as of March 23, 2001, by and among Altus,
       ACGL and the other shareholders of Altus. Prior to the acquisition, ACGL
       owned a 27.9% minority interest in Altus' common stock. Following the
       acquisition, Altus' name was changed to Arch Risk Transfer Services Ltd.


                                       27
<Page>

ITEM 7.  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

(b) PRO FORMA FINANCIAL INFORMATION.

OVERVIEW

       On June 22, 2001, ACGL acquired all of the capital stock of Altus, a
Cayman Islands company, that it did not already own, pursuant to the
Reorganization Agreement dated as of March 23, 2001, by and among Altus, ACGL
and the other shareholders of Altus, for a purchase price of approximately $38.8
million. The purchase price consisted of approximately $38.4 million in cash and
24,200 ACGL Common Shares issued to employee shareholders continuing in
management positions. Prior to the acquisition, ACGL owned a 27.9% minority
interest in Altus' common stock. Following the acquisition, Altus' name was
changed to Arch Risk Transfer Services Ltd.

       Upon the closing of ACGL's acquisition of Altus, ACGL was required under
generally accepted accounting principles governing a "step acquisition" of an
investee company to retroactively adopt the equity method of accounting for its
original 27.9% ownership interest in Altus for the periods prior to the
acquisition and to restate its historical financial results. Such restatement
resulted in a reduction in ACGL's book value at March 31, 2001 in the amount of
$3.1 million, or $0.24 per share. After ACGL's acquisition of its initial 27.9%
ownership interest in Altus in March 1998, the investment was carried at its
estimated fair value from the initial purchase through March 31, 2001 in
accordance with generally accepted accounting principles. ACGL accounted for its
initial interest in Altus under "fair value" because ACGL did not have the
ability to exercise significant influence over this investment due to ACGL's
limited voting and consent rights.

       Subsequent to this Form 8-K/A report, ACGL will file with the Securities
and Exchange Commission ("SEC") an amended Form 10-K (10-K/A) for the year ended
December 31, 2000 and an amended Form 10-Q (10-Q/A) for the quarter ended March
31, 2001 to reflect the required restatement. See note 5 to the unaudited pro
forma financial statements contained in this report.

       The following unaudited pro forma condensed combined financial statements
as of and for the quarter ended March 31, 2001 and for the year ended December
31, 2000 are based on the historical financial statements of Altus included
elsewhere in this Form 8-K/A, and the historical financial statements of ACGL
included in its Annual Report on Form 10-K for the year ended December 31, 2000
and its Quarterly Report on Form 10-Q for the quarter ended March 31, 2001 (See
note 5 to the unaudited pro forma financial statements). The unaudited pro forma
financial statements give effect to the transactions consummated pursuant to the
Reorganization Agreement.

       The unaudited pro forma condensed combined statements of income have been
prepared to reflect the acquisition of Altus by ACGL as if the acquisition had
occurred as of January 1, 2000. The unaudited pro forma condensed combined
statement of financial condition reflects the acquisition as if it had occurred
on March 31, 2001. The pro forma adjustments made in connection with the
development of the pro forma information are preliminary and have been made
solely for the purposes of developing such pro forma information. The final
allocation may be different from these estimates and there can be no assurances
that such differences, if any, will not be material.

       The pro forma information does not purport to be indicative of the
results of operations that would have occurred had the transaction been
consummated on the assumed dates, nor is the information intended to be a
projection for any future period. The unaudited pro forma financial information
should be read in conjunction with the related notes thereto and the historical
financial statements of Altus included herein, and the historical financial
statements of ACGL.


                                       28
<Page>

UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET
(IN THOUSANDS)

<Table>
<Caption>
                                                                           MARCH 31, 2001
                                                   -----------------------------------------------------------------
                                                                                              PRO FORMA
                                                                                  ----------------------------------
                                                     ACGL          ALTUS          ADJUSTMENTS               COMBINED
                                                   --------       --------        -----------               --------
                                                                                                
ASSETS
Investments:
Fixed maturities                                    $90,400        $56,197                                  $146,597
Publicly traded equity securities                    28,224                                                   28,224
Privately held securities                            52,080                         ($16,000)   (2)           36,080
Securities held in escrow                            21,373                                                   21,373
Short-term investments                               72,421            525           (38,398)   (3)           34,548
                                                   --------       --------          --------                --------
Total investments                                   264,498         56,722           (54,398)                266,822
                                                   --------       --------          --------                --------

Cash                                                 20,290          7,864                                    28,154
Accrued investment income                             2,405            688                                     3,093
Premiums receivable                                  39,459         15,461                                    54,920
Unpaid claims and claims expenses recoverable        34,520         33,147                                    67,667
Prepaid reinsurance premiums                         31,735         31,777                                    63,512
Reinsurance balances receivable                       9,654          3,153                                    12,807
Goodwill                                             20,381                            5,343  (1), (4)        25,724
Deferred income tax asset                             7,980                                                    7,980
Deferred policy acquisition costs                     2,485          2,505                                     4,990
Other assets                                          6,829          3,945                                    10,774
                                                   --------       --------          --------                --------
TOTAL ASSETS                                       $440,236       $155,262          ($49,055)               $546,443
                                                   ========       ========          ========                ========

LIABILITIES
Claims and claims expenses                          $53,413        $37,585                                   $90,998
Unearned premiums                                    44,133         46,378                                    90,511
Reinsurance balances payable                         34,282         15,855                                    50,137
Reserve for contingent loss of escrowed assets       15,000                                                   15,000
Investment accounts payable                           5,792                                                    5,792
Other liabilities                                    15,135          9,038                                    24,173
                                                   --------       --------          --------                --------
TOTAL LIABILITIES                                   167,755        108,856                                   276,611
                                                   --------       --------          --------                --------

SHAREHOLDERS' EQUITY                                272,481         46,406           (49,055)   (5)          269,832
                                                   --------       --------          --------                --------

TOTAL LIABILITIES & SHAREHOLDERS' EQUITY           $440,236       $155,262          ($49,055)               $546,443
                                                   ========       ========          ========                ========
</Table>

     The accompanying notes are an integral part of the unaudited pro forma
                    condensed combined financial statements.


                                       29
<Page>



UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF INCOME
(IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)

<Table>
<Caption>
                                                                FOR THE THREE MONTHS ENDED MARCH 31, 2001
                                                         ---------------------------------------------------------
                                                                                             PRO FORMA
                                                                                    ------------------------------
                                                           ACGL         ALTUS       ADJUSTMENTS           COMBINED
                                                         --------     --------      -----------           --------
                                                                                                
REVENUES
Net premiums written                                       $2,837       $4,495                              $7,332
(Increase) decrease in unearned premiums                   (1,204)       1,274                                  70
                                                         --------     --------        --------            --------
Net premiums earned                                         1,633        5,769                               7,402
Net investment income                                       3,160          973                               4,133
Net investment gains                                        9,004          279                               9,283
Equity in net income of investees                           1,036                                            1,036
Fee income                                                  1,715        1,078                               2,793
Net commission income                                         482                                              482
                                                         --------     --------        --------            --------
Total revenues                                             17,030        8,099                              25,129
                                                         --------     --------        --------            --------

OPERATING COSTS AND EXPENSES
Claims and claims expenses                                  1,545        4,637                               6,182
Commissions and brokerage                                                2,024                               2,024
Other operating expenses                                    4,038        2,145             $89   (7)         6,272
                                                         --------     --------        --------            --------
Total operating costs and expenses                          5,583        8,806              89              14,478
                                                         --------     --------        --------            --------

Income (Loss) Before Income Taxes                          11,447         (707)           (89)              10,651
                                                         --------     --------        --------            --------

Income taxes:
Current                                                       201                                              201
Deferred                                                    3,105         (178)                  (8)         2,927
                                                         --------     --------        --------            --------
Income tax expense (benefit)                                3,306         (178)                              3,128
                                                         --------     --------        --------            --------

Net Income (Loss)                                          $8,141        ($529)           ($89)             $7,523
                                                         ========     ========        ========            ========

AVERAGE SHARES OUTSTANDING
Basic                                                      12,787                           24   (9)        12,811
Diluted                                                    12,792                           24   (9)        12,816

PER SHARE DATA
Net Income - Basic                                          $0.64                                            $0.59
Net Income - Diluted                                        $0.64                                            $0.59
</Table>

     The accompanying notes are an integral part of the unaudited pro forma
                    condensed combined financial statements.


                                       30
<Page>

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF INCOME
(IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)

<Table>
<Caption>
                                                                  FOR THE YEAR ENDED DECEMBER 31, 2000
                                                         ---------------------------------------------------------
                                                                                              PRO FORMA
                                                                                    ------------------------------
                                                           ACGL         ALTUS       ADJUSTMENTS           COMBINED
                                                         --------     --------      -----------           --------
                                                                                              
REVENUES
Net premiums written                                     ($10,604)     $24,243                             $13,639
(Increase) decrease in unearned premiums                   98,134       (5,107)                             93,027
                                                         --------     --------        --------            --------
Net premiums earned                                        87,530       19,136                             106,666
Net investment income                                      15,923        3,280                              19,203
Gain on sale of reinsurance operations                      2,191                                            2,191
Net investment gains                                       16,872           62          $3,173   (6)        20,107
Equity in net income of investees                           2,539                                            2,539
Fee income                                                                  74                                  74
                                                         --------     --------        --------            --------
Total revenues                                            125,055       22,552           3,173             150,780
                                                         --------     --------        --------            --------

OPERATING COSTS AND EXPENSES
Claims and claims expenses                                 76,263       10,986                              87,249
Commissions and brokerage                                  26,756       12,170                              38,926
Reserve for contingent loss of escrowed assets             15,000                                           15,000
Other operating expenses                                    7,953        1,686             356   (7)         9,995
Foreign exchange loss                                       1,159                                            1,159
                                                         --------     --------        --------            --------
Total operating costs and expenses                        127,131       24,842             356             152,329
                                                         --------     --------        --------            --------

Income (Loss) Before Income Taxes and
Discontinued Operations                                   (2,076)       (2,290)          2,817              (1,549)
                                                         --------     --------        --------            --------

Income taxes:
Current                                                                     17                                  17
Deferred                                                    6,665         (109)                  (8)         6,556
                                                         --------     --------        --------            --------
Income tax expense (benefit)                                6,665          (92)                              6,573
                                                         --------     --------        --------            --------

Loss From Continuing Operations                           ($8,741)     ($2,198)         $2,817             ($8,122)
                                                         ========     ========        ========            ========

AVERAGE SHARES OUTSTANDING
Basic                                                      13,198                           24   (9)        13,222
Diluted                                                    13,198                           24   (9)        13,222

PER SHARE DATA
Net Loss - Basic                                           ($0.66)                                          ($0.61)
Net Loss - Diluted                                         ($0.66)                                          ($0.61)
</Table>

     The accompanying notes are an integral part of the unaudited pro forma
                    condensed combined financial statements.

                                       31
<Page>

NOTES TO THE UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

       The acquisition of Altus has been accounted for as a business combination
using the purchase method. The purchase price for this acquisition is the sum of
consideration paid and the transaction costs incurred by ACGL. Under the
purchase method of accounting for business combinations, the purchase price is
allocated to the assets and liabilities based on their fair values, with the
excess of the acquisition costs over the fair value of the net assets recorded
as goodwill.

(1)    Preliminary analyses have been performed in order to identify intangible
       assets and to allocate purchase price to identifiable assets and
       liabilities, with the excess of purchase price over net tangible and
       intangible assets recorded as goodwill. The fair values of reserves for
       claims and claims expenses and related reinsurance recoverables for
       Altus' subsidiary, First American Insurance Company, were estimated based
       on the present value of the expected underlying cash flows of the
       reserves and reinsurance recoverables using a risk free interest rate,
       and include an adjustment for a risk factor and a profit margin. The
       following table summarizes the calculation and allocation of purchase
       price of the most recent acquisition:

<Table>
<Caption>
       (in thousands)                                                              ALTUS
                                                                                  -------
                                                                               
       PURCHASE PRICE:
       Consideration paid in cash                                                 $37,985
       Consideration paid in stock                                                    404
       Transaction costs                                                              413
                                                                                  -------
         Total Purchase Price                                                      38,802
       Original ACGL 27.9% investment (after adjustment described in notes 2
       and 5)                                                                      12,947
                                                                                  -------
         Total Investment                                                         $51,749
                                                                                  =======
       PURCHASE PRICE ALLOCATION:
       Fair value of net assets acquired                                           33,459
       Goodwill                                                                     5,343
                                                                                  -------
         Total Allocation of Purchase Price                                        38,802
       Original ACGL 27.9% investment (after adjustment described in notes 2
       and 5)                                                                      12,947
                                                                                  -------
         Total Investment                                                         $51,749
                                                                                  =======
</Table>

(2)    To eliminate ACGL's original minority investment in Altus, which was
       carried at estimated fair value prior to the closing of the acquisition
       on June 22, 2001.

(3)    To record consideration paid to Altus' shareholders of $38.0 million and
       acquisition expenses, consisting primarily of transaction fees and
       professional services in the amount of $0.4 million.

(4)    To record the value of goodwill (as described in note 1) of $5.3 million.


                                       32
<Page>

(5)    To reflect the elimination of Altus' shareholders' equity of $46.4
       million, the issuance of 24,200 shares of ACGL Common Shares valued at
       $0.4 million, and ACGL's 27.9% portion of equity in the net loss of Altus
       occurring prior to March 31, 2001 in the amount of $3.1 million.

       Upon the closing of ACGL's acquisition of Altus, ACGL was required under
       generally accepted accounting principles governing a "step acquisition"
       of an investee company to retroactively adopt the equity method of
       accounting for its original 27.9% ownership interest in Altus for the
       periods prior to the acquisition and to restate its historical financial
       results. Such restatement resulted in a reduction in ACGL's book value at
       March 31, 2001 in the amount of $3.1 million, or $0.24 per share. After
       ACGL's acquisition of its initial 27.9% ownership interest in Altus in
       March 1998, the investment was carried at its estimated fair value from
       the initial purchase through March 31, 2001 in accordance with generally
       accepted accounting principles. ACGL accounted for its initial interest
       in Altus under "fair value" because ACGL did not have the ability to
       exercise significant influence over this investment due to ACGL's limited
       voting and consent rights.

       Subsequent to this Form 8-K/A report, ACGL will file with the Securities
       and Exchange Commission ("SEC") an amended Form 10-K (10-K/A) for the
       year ended December 31, 2000 and an amended Form 10-Q (10-Q/A) for the
       quarter ended March 31, 2001 to reflect the required restatement. ACGL's
       historical financial statements have not been restated herein. However,
       the cumulative result of retroactively adopting the equity method of
       accounting for the original investment in Altus is included as a pro
       forma adjustment to shareholders' equity as follows:

<Table>
                                                                                         
       Elimination of Altus' shareholders' equity                                           ($46,406)
       Issuance of ACGL Common Shares to employee shareholders of Altus                          404
       Cumulative net result of retroactively adopting the equity method of accounting        (3,053)
                                                                                            --------
         Pro Forma Adjustment                                                               ($49,055)
                                                                                            ========
</Table>

(6)    To eliminate the $3.2 million realized loss recorded in the first quarter
       2000 historical financial statements as an adjustment to the fair value
       of ACGL's investment in Altus. This item would not be recorded under the
       equity method. See note 5 above regarding the step acquisition.

(7)    To record the amortization of goodwill related to the acquisition of
       Altus as if the transaction occurred on January 1, 2000. Goodwill in
       relation to the acquisition was $5.3 million (see note 1) and will be
       amortized on a straight-line basis over fifteen years.

(8)    The amortization of goodwill related to the Altus acquisition is not
       deductible for tax purposes; therefore, no tax effect has been included.

(9)    Weighted average shares used to calculate pro forma basic and diluted net
       income (loss) per share for the periods presented are computed using the
       historical weighted average number of common shares outstanding for the
       period presented and the shares issued in conjunction with the
       acquisition of Altus as if such issued shares were outstanding as of
       January 1, 2000.

                                       33
<Page>

                                  EXHIBIT INDEX


EXHIBIT NO.                       DESCRIPTION
- -----------       ---------------------------------------------

23(a)             Consent of Deloitte & Touche LLP