Aspen Reshapes Insurance Segment Leadership

Hamilton, Bermuda – 25 June, 2012 – Aspen Insurance Holdings Limited (“Aspen” or the “Company”; Ticker: NYSE:AHL; BSX: AHL.BH) today announces changes to the management of its Insurance segment.

Effective 01 July, 2012, Rupert Villers (co-CEO, Aspen Insurance) will assume a new position as Chairman of Aspen Insurance and President of Aspen International Insurance. Mario Vitale (co-CEO Aspen Insurance) will become CEO of Aspen Insurance globally and remain President of Aspen US Insurance.

Rupert Villers has agreed to extend his service with Aspen until the end of 2014. He will serve as Chairman of Aspen Insurance, advising and supporting the development and execution of Aspen Insurance’s business strategy. He will also serve as President of International Insurance, where he will support the development of strategy for Aspen’s International Insurance business and continue to be responsible for the day-to-day management of Aspen Insurance’s International underwriting teams.

Mario Vitale will become CEO of Aspen Insurance. In this capacity he will develop, establish and execute Aspen Insurance’s business strategy and manage the day-to-day business of Aspen Insurance globally. He will also continue to serve as President of US Insurance, managing Aspen Insurance’s US underwriting teams and its US insurance operating platform.

Commenting on the changes, Aspen’s CEO, Chris O’Kane said: “Since early 2011, Aspen Insurance has had considerable success in realizing its strategic objectives under the combined leadership of Rupert Villers and Mario Vitale. As a result of the changes, Aspen will continue to benefit from Rupert Villers’ expertise and has put in place a firm foundation for the future strategic leadership and direction of our Insurance business under Mario Vitale.”

About Aspen Insurance Holdings Limited (“Aspen”)

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 Kingdom and the United States. For the year ended December 31, 2011, Aspen reported $9.5 billion in total assets, $4.5 billion in gross reserves, $3.2 billion in shareholders’ equity and $2.2 billion in gross written premiums. Its operating subsidiaries have been assigned a rating of “A” (“Strong”) by Standard & Poor’s (“S&P”), an “A” (“Excellent”) by A.M. Best and an “A2” (“Good”) by Moody’s Investors Service (“Moody’s”).

For further information please visit www.aspen.co or contact:

Investors

Kerry Calaiaro, Senior Vice President, Investor Relations, Aspen

Kerry.Calaiaro@aspen.co

+1 646 502 1076