Endurance Sends Letter Urging Fellow Aspen Shareholders to Make Their Voices Heard: "Tell Aspen It's Time to Put Entrenched Interests Aside and Focus on the Clear Benefits of Endurance's Offer"

Aspen`s Performance Under Current Board and Management Has Significantly Lagged Endurance

Aspen`s Board and Management Have Not Shown That They Can or Will Deliver Value to Aspen Shareholders

Aspen Shareholders Should Vote FOR Endurance`s Two Proposals by Signing, Dating and Returning the WHITE Card by July 25th

PEMBROKE, Bermuda, July 10, 2014 - Endurance Specialty Holdings Ltd. ("Endurance") (ENH) is urging fellow shareholders of Aspen Insurance Holdings Limited ("Aspen") (AHL) to make their voices heard and tell Aspen`s board and management it`s time to put entrenched interests aside and focus on the clear benefits of Endurance`s offer.

In a letter being sent to Aspen shareholders, Endurance requests that Aspen shareholders vote FOR its proposals to requisition a special general meeting of shareholders in connection with Endurance`s proposal to increase the size of Aspen`s board of directors from 12 to 19 directors and to authorize support for the proposal of a Scheme of Arrangement by Endurance. By voting FOR Endurance`s two proposals on the WHITE card, Aspen shareholders would be taking concrete action towards realizing the significant upfront premium and opportunity for long-term value of Endurance`s offer.

In its letter, Endurance reminds Aspen shareholders that it has set July 25, 2014 as the target date for voting on its two proposals.

The letter being mailed to Aspen common shareholders reads as follows:

Dear Fellow Aspen Shareholder:

Nearly half a year has gone by since Endurance first proposed to acquire all of the common shares of Aspen for a highly attractive premium and a compelling opportunity for future value creation. By now one would have expected Aspen`s board and management to have acted upon Endurance`s offer, thereby realizing significant value for Aspen shareholders. Instead, Aspen`s board and management have consistently taken actions to entrench their position and try to prevent the true owners of Aspen from realizing the significant benefits of Endurance`s offer - none of these actions is in the best interests of Aspen`s shareholders.

Don`t be fooled by Aspen`s dubious assurances about its "standalone plan." Under the stewardship of its current board and management, Aspen`s performance has lagged that of Endurance across key metrics, including underwriting profitability (i.e., combined ratio), diluted book value per share growth and share price performance. Despite the efforts of Aspen`s board and management to distort the truth and confuse shareholders, there is no denying the facts:

What has been the response of Aspen`s board and management to their chronic underperformance? Actions that we believe are not in the best long-term interests of Aspen`s shareholders.