Exhibit 10.1

COMMITMENT INCREASE SUPPLEMENT

COMMITMENT INCREASE SUPPLEMENT, dated September 1, 2006 (this ‘‘Supplement’’),
to the Credit Agreement dated as of August 2, 2005 (as amended, supplemented or
otherwise modified from time to time, the ‘‘Credit Agreement’’), among Aspen
Insurance Holdings Limited, a Bermuda exempted limited liability company (the
‘‘Company’’), the Subsidiary Borrowers (as defined therein) (together with the
Company, collectively, the ‘‘Borrowers’’ and individually, a ‘‘Borrower’’), the
Lenders parties thereto, The Bank of New York, as Collateral Agent, Bank of
America, N.A. and Calyon, New York Branch, as Co-Syndication Agents, Credit
Suisse, Cayman Islands Branch and Deutsche Bank AG, New York Branch, as
Co-Documentation Agents, and Barclays Bank PLC, as Administrative Agent. Unless
otherwise defined herein, terms defined in the Credit Agreement and used herein
shall have the meanings given to them in the Credit Agreement.

W I T N E S S E T H:

WHEREAS, pursuant to Section 2.1(b) of the Credit Agreement, the Borrowers have
the right, subject to the terms and conditions thereof, to effectuate from time
to time an increase in the aggregate Commitments under the Credit Agreement by
requesting one or more Lenders to increase the amount of its Commitment;

WHEREAS, the Borrowers have given notice to the Administrative Agent and the
Issuing Lenders of their intention to increase the Total Commitments pursuant to
Sections 2.1(b) and (c) of the Credit Agreement; and

WHEREAS, pursuant to Sections 2.1(b) and (c) of the Credit Agreement, the
undersigned Lender now desires to increase the amount of its Commitment under
the Credit Agreement by executing and delivering to the Borrowers, the
Administrative Agent and the Issuing Lenders a supplement to the Credit
Agreement in substantially the form of this Supplement;

NOW THEREFORE, each of the parties hereto hereby agrees as follows:

[spacer.gif] [spacer.gif] [spacer.gif] 1.  The undersigned Lender agrees,
subject to the terms and conditions of the Credit Agreement, that on the date of
this Supplement it shall have its Commitment increased by $[        ], thereby
making the aggregate amount of its Commitment equal to $[            ].

[spacer.gif] [spacer.gif] [spacer.gif] 2.  This Supplement shall be governed by,
and construed in accordance with, the laws of the State of New York.

[spacer.gif] [spacer.gif] [spacer.gif] 3.  This Supplement may be executed in
any number of counterparts and by different parties hereto in separate
counterparts, each of which when so executed shall be deemed to be an original
and all of which taken together shall constitute one and the same document.

--------------------------------------------------------------------------------

Accepted and agreed to, for the Borrowers, as of the date first written above:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
ASPEN INSURANCE HOLDINGS LIMITED   [spacer.gif] [spacer.gif] By: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]  
[spacer.gif]

--------------------------------------------------------------------------------

Acknowledged and agreed to as of the date first written above:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
BARCLAYS BANK PLC, as Administrative Agent   [spacer.gif] [spacer.gif] By:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]   [spacer.gif]

[spacer.gif]

--------------------------------------------------------------------------------

Acknowledged and agreed to as of the date first written above:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
BARCLAYS BANK PLC, as Issuing Lender   [spacer.gif] [spacer.gif] By:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
BARCLAYS BANK PLC   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
BANK OF AMERICA, N.A.   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]
  [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
CALYON, NEW YORK BRANCH   [spacer.gif] [spacer.gif] By: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
CREDIT SUISSE, CAYMAN ISLANDS BRANCH   [spacer.gif] [spacer.gif] By:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]     [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
DEUTSCHE BANK AG, NEW YORK BRANCH   [spacer.gif] [spacer.gif] By: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
ABN AMRO BANK N.V.   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] By: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]     [spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
CITIBANK, N.A.   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
THE BANK OF NEW YORK   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
THE BANK OF N.T. BUTTERFIELD & SON LIMITED   [spacer.gif] [spacer.gif] By:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
HSBC BANK, USA, N.A.   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------

IN WITNESS WHEREOF, each of the undersigned has caused this Supplement to be
executed and delivered by a duly authorized officer on the date first above
written:

[spacer.gif]

[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]
[spacer.gif] [spacer.gif] [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]
UBS LOAN FINANCE LLC   [spacer.gif] [spacer.gif] By: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Name: [spacer.gif]
[spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif] [spacer.gif] Title:
[spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]     [spacer.gif]
[spacer.gif] By: [spacer.gif] [spacer.gif]   [spacer.gif] [spacer.gif]    
[spacer.gif] [spacer.gif] Name: [spacer.gif] [spacer.gif]   [spacer.gif]
[spacer.gif]     [spacer.gif] [spacer.gif] Title: [spacer.gif] [spacer.gif]  
[spacer.gif] [spacer.gif]   [spacer.gif]

--------------------------------------------------------------------------------