Exhibit 10.5

FIRST AMENDMENT

THIS FIRST AMENDMENT dated as of June 22, 2007 (this “Amendment”) amends the
Credit Agreement dated as of December 13, 2005 (the “Credit Agreement”) among
ACE European Holdings No.2 Limited (the “Borrower”), ACE Limited (the
“Guarantor”), various financial institutions and The Royal Bank of Scotland plc,
as Agent. Capitalized terms used but not defined herein have the respective
meanings set forth in the Credit Agreement.

Pursuant to the Guarantor’s request, the parties have agreed to amend the Credit
Agreement to delete the Restricted Payments covenant set forth in Section 16.5.
Accordingly, the parties hereto agree as follows:

SECTION 1. Amendment to Credit Agreement. Section 16.5 is amended in its
entirety to read as follows:

16.5 [Intentionally Deleted].

SECTION 2. Representations and Warranties. Each Obligor represents and warrants
as follows:

2.1 Authorization. The execution, delivery and performance by such Obligor of
this Amendment are within its corporate powers, have been duly authorized by all
necessary action, and do not: (i) contravene its organizational documents or any
contractual restriction, law or governmental regulation or court decree or order
that is binding on such Obligor or (iii) require any consent, approval,
authorization or other action by, or notice to, or registration or filing with,
any governmental authority or other Person.

2.2 Enforceability. This Amendment constitutes the legal, valid and binding
obligation of such Obligor enforceable against such Obligor in accordance with
its terms, subject to applicable bankruptcy, insolvency and similar laws
affecting creditors’ rights and general equitable principles.

2.3 Representations and Warranties; No Default. After giving effect to this
Amendment: (i) each of the representations and warranties of the Obligors
contained in the Credit Agreement (excluding the representation and warranty set
forth in Section 14.6) is true and correct on and as of the date hereof with the
same effect as if made on and as of the date hereof (except to the extent any
such representation or warranty is expressly stated to have been made as of a
specific date, in which case such representation or warranty was true and
correct as of such date) and (ii) no Default or Event of Default has occurred
and is continuing.

SECTION 3. Effectiveness. This Amendment shall become effective as of the date
set forth above when the Agent has received counterparts hereof signed by
Obligors and the Majority Banks.

SECTION 4. Miscellaneous.

4.1 Effect of Amendment. After the effectiveness hereof, all references to the
Credit Agreement set forth in any other agreement or instrument shall, unless
otherwise specifically provided, be references to the Credit Agreement as
amended hereby. Except as so amended, the Credit Agreement shall remain in full
force and effect in accordance with its terms.

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4.2 Governing Law. This Amendment shall be governed by and construed and
enforced in accordance with English law.

4.3 Successors and Assigns. This Amendment shall be binding upon, inure to the
benefit of and be enforceable by the respective successors and assigns of the
parties hereto.

4.4 Construction. Headings used herein are for convenience of reference only and
shall not affect the meaning of this Amendment.

4.5 Counterparts. This Amendment may be executed in any number of counterparts
and by different parties hereto on separate counterparts, each of which shall be
an original and all of which taken together shall constitute one and the same
agreement. Delivery to the Agent of a signed counterpart hereof, or signature
page hereto, by facsimile or e-mail (in a .pdf or similar file) shall be
effective as delivery of an original manually-signed counterpart.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed
by their duly authorized officers as of the date first above written.

 

ACE EUROPEAN HOLDINGS NO.2 LIMITED

By:  

 

Title:  

 

ACE LIMITED

By:  

 

Title:  

 

(signatures continue on the following page)

 

Signature Page to First Amendment to ACE European Holdings No.2 Limited Credit
Agreement

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THE ROYAL BANK OF SCOTLAND PLC, as Agent and as a Bank

By:  

 

Title:  

 

(signatures continue on the following page)

 

Signature Page to First Amendment to ACE European Holdings No.2 Limited Credit
Agreement

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[Type or Print Name of Financial Institution]

By:

 

 

Name:  

 

Title:  

 

 

Signature Page to First Amendment to ACE European Holdings No.2 Limited Credit
Agreement