Aspen Insurance Holdings Announces Preliminary Deepwater Horizon Loss Estimate

Hamilton, Bermuda – 10 June, 2010 — Aspen Insurance Holdings Limited ("Aspen"; Tickers: NYSE:AHL & AHL.BH) today announced its preliminary loss estimate for claims arising from the Deepwater Horizon disaster.  It is not yet possible to estimate the environmental and economic consequences of the disastrous oil spill at Deepwater Horizon and we remain deeply disturbed by the ecological and human consequences as this event continues to unfold.

Having monitored events in recent weeks, Aspen believes, however, that it is now more feasible to estimate the insurance consequences of this event and has evaluated a range of scenarios concerning the ultimate insurance liabilities for the different parties involved. The results suggest that Aspen’s loss from this event, net of tax and reinstatement premiums is unlikely to exceed $25 million.  Aspen also believes that the majority of scenarios including those which are most likely to occur will cost Aspen substantially less than $25 million.

About Aspen Insurance Holdings Limited

Aspen 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 States and the United Kingdom. For the twelve months ended December 31, 2009, Aspen 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 rating of “A” (“Strong”) by Standard & Poor’s, an “A” (“Excellent”) by A.M. Best and an “A2” (“Good”) by Moody’s Investors Service. For more information about Aspen, please visit www.aspen.bm.

As additional loss information becomes available and as greater clarity is achieved in respect of the uncertainties enumerated below and the complex nature of this loss, the Company may revise this estimate.

All forward-looking statements address matters that involve risks and uncertainties.  Accordingly, there are or will be important factors that could cause actual results to differ materially from those indicated in these statements. Aspen believes these factors include, but are not limited to, in respect of the losses from the explosion of Deepwater Horizon, significant uncertainties concerning the likely contractual relationships between the parties involved and their impact on apportionment of liability, any intervening legislative or governmental action, developing information available from brokers, the receipt of actual loss reports,  forecasts of losses relating to the Deepwater Horizon explosion for the industry as a whole and for individual companies,  changes in the total industry losses or the Company's share of such losses, the actual number of the Company’s insureds incurring losses from these events, the effectiveness of the Company’s loss limitation methods, and the amount and timing of reinsurance recoverables and reimbursements actually received by the Company from its reinsurers, if any, as are due from this loss.  For a more detailed description of these uncertainties and other factors which could cause results to differ materially, please see the "Risk Factors" section in Aspen's Annual Report on Form 10-K as filed with the U.S. Securities and Exchange Commission on February 26, 2010.  Aspen undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the dates on which they are made.

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