Aspen Insurance Holdings Updates Loss Estimate for New Zealand Earthquake

Hamilton, Bermuda – 17 December, 2010 — Aspen Insurance Holdings Limited (the “Company”; NYSE:AHL) announced that it has updated its pre-tax loss estimate for the New Zealand earthquake, which occurred in September 2010, from US$20 million to US$53 million, net of reinstatement premiums. This equates to US$47 million post tax. Aspen’s current loss estimate is consistent with an industry loss of NZ$5.5 billion (US$4.1 billion) from the New Zealand earthquake.

The upward revision reflects new information and is mainly due to one large domestic New Zealand cedant, which comprises approximately 81% of Aspen’s total loss estimate for this event. Aspen’s initial estimate of a NZ$2.2 billion loss for this cedant included a margin for conservatism above the top end of the client’s original estimated range of NZ$1-2 billion. The latest information from this client indicates a substantial increase with a wide range of possible outcomes. Given the continuing uncertainty associated with this loss, Aspen has now concluded that it is prudent to reserve at a total loss for Aspen’s shares on this program, which assumes a loss of at least NZ$3.5 billion for this client. Aspen has also reserved at a total loss for all other domestic New Zealand placements.  The balance of Aspen’s loss is $5 million and comprises shares on programs for clients domiciled outside of New Zealand which include some New Zealand exposure.

About Aspen Insurance Holdings Limited

The Company provides reinsurance and insurance coverage to clients in various domestic and global markets through wholly-owned subsidiaries and offices in Bermuda, France, Germany, Ireland, Singapore, Switzerland, the United Kingdom and the United States. For the twelve months ended December 31, 2009, The Company reported gross written premiums of $2,067.1 million, net income of $473.9 million and total assets of $8.3 billion. Its operating subsidiaries have been assigned a financial strength rating of “A” (“Strong”) by Standard & Poor's, an “A” (“Excellent”) by A.M. Best and an “A2” (“Good”) by Moody's Investors Service.

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