Document:

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                                                                   Exhibit 10.23

                                    AGREEMENT

                  This Agreement ("Agreement") is made by and among Alleghany
Corporation ("Alleghany"), Underwriters Reinsurance Company ("URC") and London
Life and Casualty Reinsurance Corporation ("London Life"). This Agreement is
effective as of the date of December 20, 2000 (the "Effective Date").

                               W I T N E S S E T H

                  WHEREAS, URC and London Life entered into the five in force
Aggregate Stop Loss Covers, including all addenda, listed on Exhibit A hereto
(the "Stop Loss Covers"); and

                  WHEREAS, URC is a wholly owned subsidiary of Underwriters Re
Group, Inc. ("URG"); and

                  WHEREAS, in connection with the sale of URG by Alleghany to
Swiss Re America Holding Corporation in May 2000, URC and London Life entered
into the Adverse Development Cover listed on Exhibit A hereto (the "ADC", and
together with the Stop Loss Covers, the "Reinsurance Treaties"); and

                  WHEREAS, as security for the performance by London Life of
obligations owed by it to URC under the ADC, London Life established a trust
(the "Trust Fund") for the benefit of URC pursuant to a trust agreement dated
May 9, 2000 (the "Trust Agreement") by and among URC, London Life and Bankers
Trust Company, as trustee (the "Trustee"); and

                  WHEREAS, Alleghany provided a letter of intention to London
Life dated December 20, 1999 in respect of certain matters arising under or
related to the Reinsurance Treaties (the "December 1999 Letter"); and

                  WHEREAS, URC and London Life desire to fully, finally and
forever determine, settle and commute all liabilities and obligations, known or
unknown, arising under or related to any and all of the Stop Loss Covers, and to
fully release each other from all past, present and future obligations arising
under or related to the said Stop Loss Covers (the "Commutation"); and

                  WHEREAS, URC and London Life desire to fully, finally and
forever rescind the ADC (the "Rescission"); and

                  WHEREAS, Alleghany and London Life desire to fully, finally
and forever determine, settle and commute all liabilities and obligations, known
or unknown, arising under or related to the December 1999 Letter or arising
under or related to any and all of the Reinsurance Treaties, and to fully
release each other from all past, present and future obligations arising under
or related to the said December 1999 Letter or the said Reinsurance Treaties
(the "Alleghany Release"); and

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                  WHEREAS, the parties have determined that it is necessary and
desirable to set forth in this Agreement the transactions required to effect the
Commutation, the Rescission and the Alleghany Release;

                  NOW, THEREFORE, in consideration of the mutual promises made
and releases granted herein, and intending to be legally bound hereby, the
parties hereto hereby agree as follows:

                  1. On the Effective Date, Alleghany will pay to London Life,
or, at the direction of London Life, Alleghany will pay to URC, an amount in
cash equal to $66,863,000 (the "Alleghany Payment"). London Life agrees that the
payment by Alleghany of the Alleghany Payment on the Effective Date will fully,
completely and forever extinguish all liabilities and obligations of Alleghany
arising under or related to the December 1999 Letter or the Reinsurance
Treaties.

                  2. On the Effective Date, URC will be paid an amount (the
"Settlement Payment") equal to $115,654,265 (one hundred fifteen million, six
hundred fifty four thousand, two hundred sixty five dollars). Of the Settlement
Payment, $86,000,000 represents the amount paid to commute and settle the Stop
Loss Covers (the "Commutation Amount"), and $29,654,265 represents the amount
paid in connection with the rescission of the ADC (the "Rescission Amount"). Of
the Rescission Amount, $28,607,040 represents the return of the ADC premium (net
of federal excise tax ("FET")), and $1,047,225 represents an interest credit on
the full amount of the ADC premium (including FET) at the rate of 6% per annum
from May 11, 2000 through the Effective Date.

                  3. The Settlement Payment will be paid to URC as follows: (i)
London Life hereby directs Alleghany to pay the Alleghany Payment in cash to URC
on the Effective Date; (ii) on the Effective Date, London Life and URC will
jointly instruct the Trustee to liquidate the assets held in the Trust Fund as
soon as reasonably possible and, upon completion of the liquidation, to pay the
proceeds of such liquidation up to $45,791,265 (the "Liquidation Amount") to
URC, with any proceeds in excess of the Liquidation Amount to be paid to London
Life; and (iii) on the Effective Date, London Life will pay to URC an amount in
cash equal to $3,000,000. In addition, following completion of the liquidation
and payment of the Liquidation Amount to URC, London Life will pay URC an
amount, such amount to represent interest on the Liquidation Amount, equal to
$7,500 per day from the Effective Date through the date that the Liquidation
Amount is paid to URC.

                  4. As of the Effective Date, London Life shall and does hereby
relinquish to and in favor of URC all of London Life's rights and interests in
respect of the Withheld Accounts, as defined in the Stop Loss Covers.

                  5. On the Effective Date, URC shall release and return to
London Life any Letters of Credit or other security held by URC under the Stop
Loss Covers as security for the performance by London Life of any of its
obligations arising under or related to the Stop Loss Covers, except as provided
in paragraph 4 above.

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                  6. London Life agrees that, if the proceeds of liquidation of
the assets of the Trust Fund are less than the Liquidation Amount, then London
Life shall promptly pay to URC an amount in cash equal to the difference between
the Liquidation Amount and the proceeds of liquidation of the assets of the
Trust Fund.

                  7. All payments to be made to URC hereunder shall be made in
United States Dollars ($) and by wire transfer to the bank account of URC
designated by URC on Schedule I to this Agreement.

                  8. As of the Effective Date, each of London Life and URC does
hereby fully, finally and forever rescind the ADC in its entirety.

                  9. In consideration of the Settlement Payment and the release
by London Life of its rights and interests in the Withheld Accounts, and of the
mutual promises made and the mutual releases granted herein, London Life and URC
each does hereby release and forever discharge the other from any and all
liabilities and obligations arising under or related to any and all of the
Reinsurance Treaties, whether such liabilities or obligations are known or
unknown, reported or unreported, and whether currently existing or arising in
the future (the "Reinsurance Treaties Released Liabilities"). Such Reinsurance
Treaties Released Liabilities shall include but are not limited to all claims,
debts, demands, allegations, actions, causes of action, suits, duties, dues,
sums of money, accounts, reckonings, bonds, specialties, indemnities,
exonerations, covenants, contracts, controversies, agreements, promises,
omissions, trespasses, variances, damages, judgements, costs, expenses and
losses whatsoever arising under or related to the Reinsurance Treaties,
including but not limited to any common law or statutory claims for fraud and
misrepresentation, or any other claims whatsoever. It is the intention of the
parties that this release shall operate as a full and final settlement of all
past, present and future obligations and liabilities of URC to London Life and
of London Life to URC arising under or related to the Reinsurance Treaties and
shall completely discharge any claim whatsoever by either URC or London Life
against the other arising under or related to the Reinsurance Treaties. URC
specifically agrees and acknowledges that Alleghany has no obligations or
liabilities to URC arising under or related to the Reinsurance Treaties.

                  10. In consideration of Alleghany's payment at the direction
of London Life of the Alleghany Payment being paid to URC as part of the
Settlement Payment, and of the mutual promises made and the mutual releases
granted herein, Alleghany and London Life each does hereby release and forever
discharge the other from any and all liabilities and obligations arising under
or related to the December 1999 Letter or arising under or related to any and
all of the Reinsurance Treaties, whether such liabilities or obligations are
known or unknown, reported or unreported, and whether currently existing or
arising in the future (the "Alleghany Released Liabilities"). Such Alleghany
Released Liabilities shall include but are not limited to all claims, debts,
demands, allegations, actions, causes of action, suits, duties, dues, sums of
money, accounts, reckonings, bonds, specialties, indemnities, exonerations,
covenants, contracts, controversies, agreements, promises, omissions,
trespasses, variances, damages, judgements, costs, expenses and losses
whatsoever arising under or related to the December 1999 Letter or arising under
or related to the Reinsurance Treaties, including but not limited to any common
law or statutory claims for fraud and misrepresentation, or any other claims
whatsoever. It is the intention of the parties that this release shall operate
as a full and final settlement of all past,

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present and future obligations and liabilities of Alleghany to London Life and
of London Life to Alleghany arising under or related to the December 1999 Letter
or the Reinsurance Treaties, and shall completely discharge any claim whatsoever
by either Alleghany or London Life against the other arising under or related to
the December 1999 Letter or the Reinsurance Treaties.

                  11. London Life and URC specifically agree and acknowledge
that the Settlement Payment is being released to URC in good faith and
constitutes fair consideration for the discharge of amounts allegedly owing now
or potentially owing in the future by London Life to URC arising under or
related to the Reinsurance Treaties.

                  12. URC may seek to collect refunds of FET paid in connection
with the commutation of URC Aggregate Excess of Loss Treaty No. 348-9 and in
connection with the ADC premium. London Life agrees to cooperate with URC, at
London Life's own expense, in URC's efforts to collect such refunds of FET to
the extent reasonably requested by URC. London Life agrees that any such refunds
of FET collected by URC shall be retained by URC.

                  13. This Agreement shall have no effect upon any reinsurance
treaties in effect between URC and London Life other than the Reinsurance
Treaties listed on Exhibit A attached hereto. By entering into this Agreement,
URC expressly does not release, modify, compromise or waive any rights it may
have under any reinsurance agreements in effect between URC and London Life
other than the Reinsurance Treaties listed on Exhibit A attached hereto.

                  14. This Agreement is made by each party, and the releases
given hereunder are given by each party, on behalf of itself, its affiliates,
parents and subsidiaries, officers, directors, shareholders and agents and their
heirs, executors, administrators, predecessors, successors and assigns and such
releases given to a party hereunder shall also release and forever discharge
such party's affiliates, parents and subsidiaries, officers, directors,
shareholders and agents and their heirs, executors, administrators,
predecessors, successors and assigns. The rights, duties and obligations set
forth in this Agreement shall inure to the benefit of and be binding upon any
and all predecessors, parents, successors, affiliates, officers, directors,
employees, subsidiaries, stockholders, liquidators, receivers and assigns of
each of the parties hereto. Nothing in this Agreement is intended to benefit any
third party.

                  15. Each party hereto expressly warrants and represents that
it is a company in good standing in its jurisdiction of incorporation; that the
execution of this Agreement is fully authorized by it; that the person executing
this Agreement on its behalf has the necessary and appropriate authority to do
so; that the execution, delivery and performance by it of this Agreement does
not and will not contravene any law, governmental rule or regulation, judgment
or order applicable to it, and does not and will not contravene any provision
of, or constitute a default under, any agreement or instrument to which it is a
party or by which its properties are bound; and that no authorization, consent
or approval of any government entity is required to make this Agreement valid
and binding upon them.

                  16. The failure of any party to enforce any provision of this
Agreement shall not be construed as a waiver by such party of such provision or
any other provision of this Agreement. No waiver of any provision of this
Agreement by any party shall be deemed a waiver of any of its other terms, nor
shall such waiver constitute a continuing waiver.

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                  17. In the event that any court of competent jurisdiction
renders a final, non-appealable order or ruling declaring this Agreement null,
void, illegal or unenforceable, it is mutually agreed by URC, London Life and
Alleghany that this Agreement shall be immediately rescinded, that the Alleghany
Payment shall be refunded by URC to Alleghany, and that the portion of the
Settlement Payment paid by London Life (including the proceeds of liquidation of
the assets of the Trust Fund paid to URC as provided in paragraph 3 above) shall
be refunded by URC to London Life, so that each of the parties hereto shall be
restored to the position it was in just prior to the making of this Agreement.

                  18. Each party to this Agreement represents and warrants to
the other parties hereto that the drafting and negotiation of this Agreement has
been participated in by each of the parties or their counsel, or both, and for
all purposes this Agreement shall be deemed to have been drafted jointly by all
parties.

                  19. Each party to this Agreement represents and warrants to
the other parties hereto that this Agreement is entered into freely, without
duress, in good faith, at arms' length, in the regular course of business and in
reliance on its own independent investigations and analyses of the facts
underlying the subject matter of this Agreement, and that except as set forth in
writing in this Agreement, the decision to execute the Agreement is not
predicated upon or influenced by any declarations, representations, warranties
or promises of any kind made directly or indirectly by the other party, or any
predecessors in interest, successors, assigns, officers, directors, employees or
agents of same.

                  20. The parties, as between and among themselves, understand
that they may have sustained damages or incurred obligations that may not yet be
manifest and that are presently unknown, but nevertheless, URC deliberately
intends and does hereby release each of London Life and Alleghany to the extent
that this Agreement so provides, and London Life deliberately intends and does
hereby release each of Alleghany and URC to the extent that this Agreement so
provides. Furthermore, the parties expressly accept and assume the risk that the
factual or legal assumptions made by either party in connection with this
Agreement may be found hereafter to be different from the true facts or law, and
the parties agree that this Agreement shall be and remain in full force and
effect notwithstanding such differences in facts or law. In this regard, the
parties specifically waive the provisions of the California Civil Code, Section
1542, which provides as follows:

                  "A general release does not extend to claims which the
                  creditor does not know or suspect to exist in his favor at the
                  time of executing the release, which, if known by him, must
                  have materially affected his settlement with the debtor."

                  21. This Agreement shall constitute the entire Agreement among
the parties as respects its subject matter and supersedes all prior or
contemporaneous discussions, understandings or agreements. No supplement,
modification, waiver or termination of this Agreement shall be binding or
enforceable unless executed in a writing signed by all of the parties hereunder,
and this provision cannot be orally waived.

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                  22. This Agreement may be executed in multiple counterparts,
each of which, when so executed and delivered, shall be an original, but such
counterparts shall together constitute one and the same instrument and
agreement.

                  23. This Agreement shall be interpreted and governed by the
laws of the State of California.

                  IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be executed by their duly authorized representatives as of the
dates indicated below.

Signed in New York, New York, this      20th     day of December 2000,
                                     -----------
For and on behalf of Alleghany Corporation

By:          /s/ David B. Cuming
             ---------------------
Title:       Senior Vice President
             ---------------------

Signed in Calabasas, California, this   20th     day of December 2000,
                                      ----------
For and on behalf of Underwriters Reinsurance Company

By:          /s/ Stephen C. Kolakowski
             ------------------------
Title:       Senior Vice President
             ------------------------

Signed in St. Michael, Barbados, W.I., this    20th    day of December 2000,
                                            ----------
For and on behalf of London Life and Casualty Reinsurance Corporation

By:          /s/ Philip S. Young
             -------------------
Title:       President & CEO
             -------------------

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                                    EXHIBIT A

                          TO THE AGREEMENT BY AND AMONG
             ALLEGHANY CORPORATION, UNDERWRITERS REINSURANCE COMPANY
              AND LONDON LIFE AND CASUALTY REINSURANCE CORPORATION,
                        EFFECTIVE AS OF DECEMBER 20, 2000

<TABLE>
<CAPTION>

URC TREATY NO.               REINSURANCE TREATY                              EFFECTIVE DATE
-------------                ------------------                              --------------
<S>                          <C>                                             <C>
349-9                        Aggregate Excess of Loss                        July 1, 1995
                             Addendum No. 1                                  January 1, 1998
                             Addendum No. 2                                  April 30, 2000

352-9                        Aggregate Excess of Loss                        July 1, 1996
                             Addendum No. 1                                  January 1, 1998
                             Addendum No. 2                                  April 30, 2000

354-9                        Aggregate Excess of Loss                        July 1, 1997
                             Addendum No. 1                                  January 1, 1998
                             Addendum No. 2                                  July 1, 1997
                                                                             April 30, 2000

355-9                        Aggregate Excess of Loss                        July 1, 1998
                             Addendum No. 1                                  April 30, 2000

356-9                        Aggregate Excess of Loss                        July 1, 1999
                             Addendum No. 1                                  April 30, 2000

ADC00                        Aggregate Excess of Loss (ADC)                  May 10, 2000

</TABLE>

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                                   SCHEDULE I

                          TO THE AGREEMENT BY AND AMONG
             ALLEGHANY CORPORATION, UNDERWRITERS REINSURANCE COMPANY
              AND LONDON LIFE AND CASUALTY REINSURANCE CORPORATION,
                        EFFECTIVE AS OF DECEMBER 20, 2000

                          URC BANK ACCOUNT INFORMATION

   The Bank of New York
   ABA 021000018
   Credit Acct:  GLA111565
   Account Name:  Institutional Custody Insurance Division

   For Further Credit to:  Underwriters Reinsurance Company
   Account #367599<PAGE>   1

                                                                Exhibit 10.25(c)

                       FIRST AMENDMENT TO CREDIT AGREEMENT

                  THIS FIRST AMENDMENT TO CREDIT AGREEMENT, dated as of February
1, 2001 (this "Amendment"), by and among Alleghany Underwriting Ltd ("AUL"),
Alleghany Underwriting Capital Ltd ("AUCL"), Talbot Underwriting Limited
("Talbot"), Alleghany Underwriting Capital (Bermuda) Ltd ("AUCBL"), Alleghany
Corporation ("Alleghany" or the "Guarantor"), Alleghany Insurance Holdings LLC
("AIHL" or the "Pledgor"), the Banks and Agents which have signed the signature
pages hereto, and Mellon Bank, N.A., as a Bank, as Issuing Bank and as
Administrative Agent for the Banks and the Issuing Bank ("Mellon").

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

                  WHEREAS, AUL, AUCL, Talbot, AUCBL, the Guarantor, the Banks
and Agents listed on the signatures pages hereof and Mellon are parties to a
Credit Agreement, dated as of August 14, 2000 (the "Original Credit Agreement"),
pursuant to which the Banks and the Issuing Bank have agreed, on the terms and
subject to the conditions described therein, to extend credit to AUL, AUCL,
Talbot and AUCBL;

                  WHEREAS, AIHL is a wholly-owned Subsidiary of the Guarantor
and AIHL owns all or substantially all of the outstanding capital stock of AUL,
AUCL, Talbot and AUCBL;

                  WHEREAS, in connection with the Original Credit Agreement, and
to provide security for the repayment of the Obligations (as that term is
defined in the Original Credit Agreement), the Guarantor, as pledgor, entered
into a Pledge Agreement, dated as of August 14, 2000 (the "Original Pledge
Agreement"), with the Administrative Agent, pursuant to which the Guarantor
granted to the Administrative Agent a security interest in all outstanding
shares of the capital stock (the "Designated Pledged Shares") of Alleghany Asset
Management, Inc.
("AAM");

                  WHEREAS, the Guarantor desires that the Designated Pledged
Shares be released from the security interest under the Original Pledge
Agreement so that they may be sold to a third party;

                  WHEREAS, the Original Credit Agreement contemplates that the
Guarantor may propose for the consent of the Required Banks, and the Guarantor
and AIHL have proposed, a "Substitution of Eligible Substitute Collateral" (as
that term is defined in the Original Credit Agreement) whereby different
collateral would be substituted for the Designated Pledged Shares pursuant to,
among other things, an amendment to the Original Pledge Agreement;

                  WHEREAS, as contemplated by the Original Credit Agreement in
connection with a Substitution of Eligible Substitute Collateral, concurrently
with the execution and delivery of this Amendment the Guarantor and AIHL are
executing and delivering to the Administrative

<PAGE>   2

Agent an Amended and Restated Pledge Agreement, pursuant to which AIHL is
pledging Eligible Substitute Collateral to the Administrative Agent for the
benefit of the Banks;

                  WHEREAS, in connection with the Substitution of Eligible
Substitute Collateral, the Guarantor and the other Credit Parties have requested
the Banks, the Issuing Bank and the Agents to make certain changes to the
Original Credit Agreement and the Required Banks, the Issuing Bank, the
Administrative Agent and the Agents signing this Amendment are willing to amend
the Original Credit Agreement as set forth below;

                  WHEREAS, AIHL desires to become a party to the Original Credit
Agreement, as amended hereby, as a guarantor and as Grantor under such Amended
and Restated Pledge Agreement; and

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

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

                  SECTION 1.  AMENDMENTS TO ORIGINAL CREDIT AGREEMENT.

                  1.1. AMENDMENTS TO DEFINITIONS. Section 1.01 of the Original
Credit Agreement is hereby amended by changing the definitions of the following
defined terms to read as follows:

                           "Covered Subsidiary" shall mean AIHL, Alleghany
         Underwriting Holdings Ltd, each of the AUHL Entities and each
         Subsidiary of any of the AUHL Entities, of Alleghany Underwriting
         Holdings Ltd or of AIHL.

                           "Credit Parties" means the Account Parties, the
         Borrowers, the Guarantor and the Pledgor, and "Credit Party" means any
         of them.

                           "Pledge Agreement" shall mean the Amended and
         Restated Pledge Agreement, dated as of February 1, 2001, between the
         Pledgor, Alleghany and the Administrative Agent, as the same shall be
         amended from time to time in accordance with the requirements of this
         Agreement.

                           "Transaction Document" or "Transaction Documents"
         shall mean this Agreement, the Pledge Agreement, the Control Agreement,
         the Continuing Letter of Credit Agreement, each Letter of Credit
         Application, each Letter of Credit, each Note, each amendment to any of
         the foregoing and any other documents or instruments executed and
         delivered in connection herewith or therewith.

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                  1.2 ADDITIONS TO DEFINITIONS. Section 1.01 of the Original
Credit Agreement is hereby further amended by adding thereto, in appropriate
alphabetical sequence, the following definitions:

                           "AIHL" shall mean Alleghany Insurance Holdings LLC, a
         Delaware limited liability company and a wholly-owned Subsidiary of
         Alleghany.

                           "Collateral Value Requirement" shall have the meaning
         ascribed to that term in Section 2.2 of the Pledge Agreement.

                           "Control Agreement" shall mean the Account Control
         Agreement, dated as of February 1, 2001, among the Pledgor, Alleghany,
         Mellon Bank, N.A., as Custodian, and the Administrative Agent, as the
         same may be amended from time to time in accordance with the
         requirements of this Agreement.

                           "Pledged Securities Available Amount" shall have the
         meaning ascribed to that term in the Pledge Agreement (i.e., "Pledged
         Securities Available Amount" at any time shall mean the amount which is
         equal to 90% of the value of the Qualifying Pledged Securities (as
         determined as a Dollar Equivalent at such time) maintained as security
         entitlements in the Pledged Account).

                           "Pledged Account" shall have the meaning ascribed to
         that term in the Pledge Agreement.

                           "Pledgor" shall mean AIHL.

                           "Pledgor Guaranteed Obligations" shall have the
         meaning ascribed to that term in Section 9A.01 hereof.

                           "Qualifying Pledged Securities" shall have the
         meaning ascribed to that term in the Pledge Agreement.

                           "Required Pledged Securities" shall have the meaning
         ascribed to that term in the Pledge Agreement.

                  1.3 AMENDMENT TO SECTION 2.01. Section 2.01(a) of the Original
Credit Agreement is hereby amended by adding thereto, as a new last sentence
thereof, the following:

         The Issuing Bank shall have no obligation to issue any Letter of Credit
         if, after such Letter of Credit were issued, the aggregate Total Credit
         Exposure of the Banks upon such issuance would exceed the Pledged
         Securities Available Amount.

                  1.4 AMENDMENT TO SECTION 3.01. Section 3.01(a) of the Original
Credit Agreement is hereby amended by adding thereto, as a new last sentence
thereof, the following:

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         A Bank shall have no obligation to make any Loan if the aggregate Total
         Credit Exposure of the Banks upon the making of such Loan would exceed
         the Pledged Securities Available Amount.

                  1.5 AMENDMENT TO SECTION 7.01(c). Section 7.01(c) of the
Original Credit Agreement is hereby amended by deleting the phrase "Alleghany
shall default in the observance, performance or fulfillment of any covenant
contained in Section 4.2 or 4.3 of the Pledge Agreement or" and by inserting in
lieu of such deleted phrase the following:

         The Pledged Securities Available Amount shall at any time be less than
         the aggregate Total Credit Exposure after the Pledgor or Alleghany
         shall have received at least one Business Day's notice thereof from the
         Administrative Agent, or the Pledgor or Alleghany shall default in the
         observance, performance or fulfillment of any covenant contained in
         Section 2.2 of the Pledge Agreement after the Pledgor or Alleghany
         shall have received at least one Business Day's notice thereof from the
         Administrative Agent, or the Pledgor or Alleghany shall default in the
         observance, performance or fulfillment of any covenant contained in
         Section 4.2, 4.3 or 4.4 of the Pledge Agreement or

                  1.6 AMENDMENT TO SECTION 7.01(l). Section 7.01(l) of the
Original Credit Agreement is hereby amended in its entirety to read as follows:

                           (l) The Pledge Agreement or either of the guarantees
         contained in Article IX and IXA hereof shall terminate or cease, in
         whole or material part, to be a legally valid and binding obligation of
         Alleghany or AIHL, as the case may be, or Alleghany, AIHL or any other
         Credit Party or any Person acting for or on behalf of any of such
         parties contests such validity or binding nature of the Pledge
         Agreement or the validity, perfection or priority of the security
         interest thereunder, or any such Person shall assert any of the
         foregoing;

                  1.7 AMENDMENT TO SECTION 9.01. The first sentence of Section
9.01 of the Original Credit Agreement is hereby amended to read as follows:

         The Guarantor hereby irrevocably, unconditionally and absolutely
         guarantees to the Agents, the Issuing Bank and the Banks, and becomes
         surety for, the prompt payment of the Obligations of the Account
         Parties and the Borrowers and the prompt payment and performance of the
         obligations of the Pledgor under the Pledge Agreement (the Obligations
         and such payment and performance obligations being collectively
         referred to herein as the "Guaranteed Obligations") in full when due
         (whether at stated maturity, by acceleration, or otherwise) strictly in
         accordance with the terms thereof.

                  1.8 AMENDMENT TO SECTIONS 9.02 AND 9.06. Each of Section 9.06
and the second sentence of Section 9.02 is hereby amended by inserting therein,
after the words "any Account Party" each time such words appear therein, the
words "or AIHL".

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                  1.9 ADDITION OF GUARANTEE BY AIHL. The Original Credit
Agreement is amended by adding thereto, between Articles IX and X thereof, a new
Article IXA to read as set forth in Exhibit A to this Amendment.

                  SECTION 2. CONDITIONS TO EFFECTIVENESS. This Amendment shall
become effective upon (i) the execution and delivery hereof by the Required
Lenders, the Administrative Agent, the Issuing Bank, Alleghany, AIHL, the
Borrowers and the Account Parties and (ii) the satisfaction of the following
conditions:

                  (a) The Administrative Agent shall have received, with
sufficient copies for all of the Banks, an opinion of U.S. counsel to the Credit
Parties to substantially the same effects, with respect to this Amendment, the
Original Credit Agreement as hereby amended and the other Transaction Documents
being delivered in connection herewith, as set forth in the opinion of such
counsel on the Closing Date;

                  (b) The Administrative Agent shall have received executed
copies of the Amended and Restated Pledge Agreement, the Account Control
Agreement related thereto and the Custody Agreement related thereto, and each of
the foregoing shall be in full force and effect;

                  (c) The Administrative Agent shall have received with respect
to Alleghany and AIHL documentation of the type contemplated by Section 5.01(a)
and (b) of the Original Credit Agreement;

                  (d) All legal details and proceedings in connection with the
transactions contemplated by this Amendment shall be reasonably satisfactory to
the Required Banks and each Bank shall have received all such counterpart
originals or certified or other copies of such documents and proceedings in
connection with such transactions, in form and substance satisfactory to the
Required Banks, as the Required Banks shall have reasonably requested; and

                  (e) There shall have been delivered to the Administrative
Agent with sufficient copies for each Bank such other certificates, opinions or
documents as may be reasonably requested by the Administrative Agent.

                  SECTION 3. DIRECTIONS TO ADMINISTRATIVE AGENT. The Required
Banks and the Issuing Bank hereby authorize and direct the Administrative Agent
to execute and deliver the Amended and Restated Pledge Agreement and the Account
Control Agreement, in substantially the respective forms of Exhibits B and C to
this Amendment, and to release the Designated Pledged Shares.

                  SECTION 4. REPRESENTATIONS AND WARRANTIES. Each of the Credit
Parties (including, for this purpose, AIHL) represents and warrants that the
representations and warranties contained in Article IV of the Original Credit
Agreement as amended hereby are true and correct on and as of the date of this
Amendment with the same effect as though made on and as of such date and no
Default and no Unmatured Default has occurred and is continuing or exists.

                                       5
<PAGE>   6

                  SECTION 5. EFFECT OF AMENDMENT. The Original Credit Agreement,
as amended by this Amendment, is in all respects ratified, approved and
confirmed and shall, as so amended, remain in full force and effect.

                  SECTION 6. GOVERNING LAW. This Amendment and the rights and
obligations of the parties hereto shall for all purposes be governed by and
construed and enforced in accordance with the substantive law of the State of
New York without giving effect to conflict of laws principles.

                  SECTION 7. COUNTERPARTS. This Amendment may be executed in any
number of counterparts and by the different parties hereto on separate
counterparts, each of which, when so executed and delivered, shall be an
original, but all such counterparts shall together constitute one and the same
instrument.

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

ALLEGHANY CORPORATION

By: /s/ David B. Cuming
    ----------------------------------------------------------
      (Signature)

Name:  David B. Cuming
       -------------------------------------------------------

Title:  Senior Vice President
        ------------------------------------------------------

ALLEGHANY INSURANCE HOLDINGS LLC

By:  /s/ David B. Cuming
  ------------------------------------------------------------
      (Signature)

Name:  David B. Cuming
    ----------------------------------------------------------

Title:  Manager
        ------------------------------------------------------

ALLEGHANY UNDERWRITING LTD

By:  /s/ Jane S. Clouting
  ------------------------------------------------------------
      (Signature)

Name:  Jane S. Clouting
       -------------------------------------------------------

Title:  Director/Secretary
     ---------------------------------------------------------

                                       6
<PAGE>   7

ALLEGHANY UNDERWRITING CAPITAL LTD

By:  /s/ Jane S. Clouting
  ------------------------------------------------------------
      (Signature)

Name:  Jane S. Clouting
       -------------------------------------------------------

Title:  Director/Secretary
     ---------------------------------------------------------

TALBOT UNDERWRITING LIMITED

By:  /s/ Jane S. Clouting
  ------------------------------------------------------------
      (Signature)

Name:  Jane S. Clouting
       -------------------------------------------------------

Title:  Director/Secretary
     ---------------------------------------------------------

ALLEGHANY UNDERWRITING CAPITAL (BERMUDA) LTD.

By:  /s/ Jane S. Clouting
  ------------------------------------------------------------
      (Signature)

Name:  Jane S. Clouting
       -------------------------------------------------------

Title:   Assistant Secretary
     ---------------------------------------------------------

MELLON BANK, N.A., AS A BANK, AS ISSUING BANK AND AS ADMINISTRATIVE AGENT

By:  /s/ Karla K. Maloof
     ---------------------------------------------------------
      (Signature)

Name:  Karla K. Maloof
       -------------------------------------------------------

Title:  Vice President
        ------------------------------------------------------

NATIONAL WESTMINSTER BANK, PLC, AS A BANK AND AS SYNDICATION AGENT

By:  /s/ John Mallett
  ------------------------------------------------------------
      (Signature)

Name:  John Mallett
    ----------------------------------------------------------

Title:  Senior Manager
     ---------------------------------------------------------

                                       7
<PAGE>   8

ING BANK, N.V., LONDON BRANCH., AS A BANK AND AS MANAGING AGENT

By:
   -----------------------------------------------------------
      (Signature)

Name:
     ---------------------------------------------------------

Title:
      --------------------------------------------------------

CREDIT LYONNAIS NEW YORK BRANCH, AS A BANK

By:  /s/ Sebastian Rocco
  ------------------------------------------------------------
      (Signature)

Name:  Sebastian Rocco
       -------------------------------------------------------

Title:  Senior Vice President
     ---------------------------------------------------------

FLEET NATIONAL BANK, AS A BANK

By:
   -----------------------------------------------------------
      (Signature)

Name:
     ---------------------------------------------------------

Title:
      --------------------------------------------------------

ABN AMRO BANK, N.V., AS A BANK

By:
   -----------------------------------------------------------
      (Signature)

Name:
     ---------------------------------------------------------

Title:
      --------------------------------------------------------

PNC BANK, NATIONAL ASSOCIATION., AS A BANK

By:
   -----------------------------------------------------------
      (Signature)

Name:
     ---------------------------------------------------------

Title:
      --------------------------------------------------------

                                       8
<PAGE>   9
                                                                       EXHIBIT A

                                   ARTICLE IXA

                              GUARANTEE OF PLEDGOR

         9A.01. The Guarantee of Pledgor. The Pledgor hereby irrevocably,
unconditionally and absolutely guarantees to the Agents, the Issuing Bank and
the Banks, and becomes surety for, the prompt payment of the Obligations of the
Account Parties and the Borrowers (the "Pledgor Guaranteed Obligations") in full
when due (whether at stated maturity, by acceleration, or otherwise) strictly in
accordance with the terms thereof. The Pledgor hereby further agrees, as a
primary obligor, that if any of the Pledgor Guaranteed Obligations are not paid
in full when due (whether at stated maturity, by acceleration, or otherwise and
whether or not such payments would not be permitted under any applicable
bankruptcy or similar law), the Pledgor will promptly pay the same, without any
demand or notice whatsoever (except as expressly provided herein), and that in
the case of any extension of time of payment or renewal of any of the Pledgor
Guaranteed Obligations, the same will be promptly paid in full when due (whether
at extended maturity, by acceleration or otherwise) in accordance with the terms
of such extension or renewal. Without limiting the generality of the foregoing,
the Pledgor Guaranteed Obligations shall include the obligations of the Account
Parties under Section 7.03 hereof.

         Notwithstanding any provision to the contrary contained herein or in
any other of the Transaction Documents, to the extent the obligations of the
Pledgor shall be adjudicated to be invalid or unenforceable for any reason
(including, without limitation, because of any applicable law, including the
insolvency laws, relating to fraudulent conveyances or transfers) then the
obligations of the Pledgor hereunder automatically shall be limited to the
maximum amount that is permissible under applicable law.

         9A.02. Obligations Unconditional. The obligations of the Pledgor under
this Article are irrevocable, absolute and unconditional (to the fullest extent
permitted by applicable law), irrespective of the value, genuineness, validity,
regularity or enforceability of any of the Transaction Documents, or any other
agreement or instrument referred to therein, or any substitution, release or
exchange of any other guarantee of or security for any of the Pledgor Guaranteed
Obligations, and, to the fullest extent permitted by applicable law,
irrespective of any other circumstance whatsoever which might otherwise
constitute a legal or equitable discharge or defense of a surety or guarantor,
it being the intent of this Article that the obligations of the Pledgor
hereunder shall be absolute and unconditional under any and all circumstances.
The Pledgor agrees that it shall have no right of subrogation, indemnity,
reimbursement or contribution against any other Credit Party for amounts paid
under this Article IXA until such time as the Banks have been paid in full, no
Pledgor Guaranteed Obligation is outstanding, the Letter of Credit Participating
Interest Commitments under this Agreement have been terminated and no Person or
Official Body shall have any right to request any return or reimbursement of
funds from any Bank in connection with monies received under the Transaction
Documents. Without limiting the generality of the foregoing, it is agreed that,
to the fullest extent permitted

                                      A-1
<PAGE>   10
by applicable law, the occurrence of any one or more of the following shall not
alter or impair the liability of the Pledgor hereunder which shall remain
irrevocable, absolute and unconditional as described above:

                  (i) at any time or from time to time, without notice to the
         Pledgor, the time for any performance of or compliance with any of the
         Pledgor Guaranteed Obligations shall be extended, or such performance
         or compliance shall be waived;

                  (ii) any of the acts mentioned in any of the provisions of any
         of the Transaction Documents, or any other agreement or instrument
         referred to in the Transaction Documents shall be done or omitted;

                  (iii) the maturity of any of the Pledgor Guaranteed
         Obligations shall be accelerated, or any of the Pledgor Guaranteed
         Obligations shall be modified, supplemented or amended in any respect,
         or any right under any of the Transaction Documents, or any other
         agreement or instrument referred to in the Transaction Documents shall
         be waived or any other guarantee of any of the Pledgor Guaranteed
         Obligations or any security therefor shall be released or exchanged in
         whole or in part or otherwise dealt with;

                  (iv) any Lien granted to, or in favor of, any Agent or any
         Bank as security for any of the Pledgor Guaranteed Obligations shall be
         void or voidable, or shall fail to attach or be perfected or any Agent
         or any Bank shall fail to realize on any collateral security; or

                  (v) any of the Pledgor Guaranteed Obligations shall be
         determined to be void or voidable (including, without limitation, for
         the benefit of any creditor of the Pledgor) or shall be subordinated to
         the claims of any Person (including, without limitation, any creditor
         of the Pledgor).

With respect to its obligations hereunder, the Pledgor hereby expressly waives
diligence, presentment, demand of payment, protest and all notices whatsoever
(except notices expressly required hereunder), and any requirement that the
Banks exhaust any right, power or remedy or proceed against any Person under any
of the Transaction Documents, or any other agreement or instrument referred to
in the Transaction Documents, or against any other Person under any other
guarantee of, or security for, any of the Pledgor Guaranteed Obligations. This
is a guarantee of payment and not merely of collection.

         9A.03. Reinstatement. The obligations of the Pledgor under this Article
shall be automatically reinstated if and to the extent that for any reason any
payment by or on behalf of any Person in respect of the Pledgor Guaranteed
Obligations is rescinded or must be otherwise restored by any holder of any of
the Pledgor Guaranteed Obligations, whether as a result of any proceedings in
bankruptcy, receivership, or reorganization or otherwise, and the Pledgor agrees
that it will indemnify the Agents and the Banks on demand for all reasonable
out-of-pocket costs and expenses (including, without limitation, reasonable fees
and expenses of counsel) incurred by any Agent or any Bank in connection with
such rescission or restoration, including any such reasonable costs and expenses
incurred in defending against any claim alleging that such

                                      A-2
<PAGE>   11
payment constituted a preference, fraudulent transfer or similar payment under
any bankruptcy, insolvency, receivership, reorganization or similar law.

         9A.04. Remedies. The Pledgor agrees that, to the fullest extent
permitted by applicable law, as between the Pledgor, on the one hand, and the
Agents and the Banks, on the other hand, the Pledgor Guaranteed Obligations may
be declared to be forthwith due and payable as provided in Section 7.02 hereof
(and shall be deemed to have become automatically due and payable in the
circumstances provided in said Section 7.02) for purposes of Section 9A.01
hereof notwithstanding any stay, injunction or other prohibition preventing such
declaration (or preventing the Pledgor Guaranteed Obligations from becoming
automatically due and payable) as to any other Person and that, in the event of
such declaration (or Pledgor Guaranteed Obligations being deemed to have become
automatically due and payable), the Pledgor Guaranteed Obligations (whether or
not due and payable by any other Person) shall forthwith become due and payable
by the Pledgor for purposes of said Section 9A.01.

         9A.05. Continuing Guarantee. The guarantee in this Article is a
continuing guarantee, and shall apply to all of the Pledgor Guaranteed
Obligations whenever arising.

         9A.06. No Restrictions. Except for restrictions under the Transaction
Documents, the Pledgor shall not be or become subject to any restriction of any
nature (whether arising by operation of Law, by agreement, by its articles of
incorporation, by-laws or other constituent documents, or otherwise) on the
right of the Pledgor from time to time to (x) pay any indebtedness, obligations
or liabilities from time to time owed to any Account Party or any Borrower, (y)
make loans or advances to any Account Party or any Borrower, or (z) transfer any
of its properties or assets to any Account Party or any Borrower.

                                      A-3

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