Aspen Appoints Stuart Sinclair President and Chief Operating Officer

Hamilton, Bermuda: August 7, 2006 - Aspen Insurance Holdings Limited ("Aspen") (NYSE: AHL) (BSX: AHL.BH) today announced the appointment of Stuart Sinclair as President and Chief Operating Officer of Aspen.  In connection with his appointment, it is expected that Mr. Sinclair also will join the company's Board of Directors. 

As President and Chief Operating Officer, Mr. Sinclair will be responsible for Aspen's internal performance and efficiency.  He will report directly to Aspen's Chief Executive Officer, Chris O'Kane, and will be based in London.  Mr. Sinclair's appointment will further Aspen's operations management at a time when the company continues to diversify its portfolio. 

"I am pleased to welcome Stuart to Aspen.  He brings a wealth of leadership experience in large international organizations and has an impressive financial services background," said Mr. O'Kane.  "I am confident that Stuart's contributions will be felt immediately, as we remain focused on enhancing our performance internally and across our business lines."

Mr. Sinclair, 53, was most recently President and CEO, Greater China, GE Financial Services, which is part of GE Capital.  Previously, he served as President and UK Chief Executive of GE Consumer Finance.  Prior to joining GE Capital, Mr. Sinclair held several positions at Royal Bank of Scotland, including CEO of Tesco Personal Finance. 

Mr. Sinclair commented: "I look forward to working closely with Chris, Aspen's management and the Board to leverage improved efficiency and communication across our diversified business lines and strategic geographic locations." 

In addition to his recent work experience, Mr. Sinclair has held a number of management consultancy roles at firms based in the United States, including Mercer Management Consulting.  He was also an International Economist, lecturing at the University of Reading and advising the Saudi Arabian Foreign Ministry. Mr. Sinclair holds an MBA from UCLA, an MA in Economic Development from Rutgers University and an MA in Economics from the University of Aberdeen.

About Aspen Insurance Holdings Limited

Aspen Insurance Holdings Limited was established in June 2002. Aspen is a Bermudian holding company that provides property and casualty reinsurance in the global market, property and liability insurance principally in the United Kingdom and the United States and specialty insurance and reinsurance consisting mainly of marine and energy and aviation worldwide. Aspen's operations are conducted through its wholly-owned subsidiaries located in London, Bermuda and the United States: Aspen Insurance UK Limited, Aspen Insurance Limited and Aspen Specialty Insurance Company. Aspen has four operating segments: property reinsurance, casualty reinsurance, specialty insurance and reinsurance and property and casualty insurance. Aspen's principal existing founding shareholders include The Blackstone Group, Candover Partners Limited and Credit Suisse First Boston Private Equity.

For more information about Aspen, please visit Aspen's website at http://www.aspen.bm.