- 21 percent premium to Aspen's closing share price on April 11, 2014;

- 15 percent premium to Aspen's all-time high share price of $41.43 on December 31, 2013;

- 1.16x Aspen's December 31, 2013 diluted book value per share; and

- 13.4x 2014 consensus Street earnings estimates for Aspen.

Each Aspen shareholder would have the right to receive for their Aspen shares, at their election: all cash ($47.50 per Aspen share); all Endurance common shares (0.8826 Endurance shares for each Aspen share); or a combination of cash and Endurance common shares.

John R. Charman, Endurance's chairman and chief executive officer, said, “This transaction is, quite simply, a unique opportunity to deliver value to shareholders of both Aspen and Endurance, while creating a new global leader in the industry. The proposal offers up-front value for Aspen's shareholders, who will receive a substantial premium for their shares, as well as the opportunity to participate – along with Endurance's shareholders – in future value created by a stronger and more profitable company.

“The specialized businesses of Endurance and Aspen, such as Endurance's market-leading agriculture insurance business and Aspen's Lloyd's operations, are highly complementary, and together we will create a company with increased scale, an attractive diversified platform across products and geographies, and greater market presence and relevance. The combined company will have a strong balance sheet and capital position, with an enhanced ability to pursue growth opportunities and to withstand volatility. Further, we believe the combined company will enjoy increased profitability driven by a strong management team comprised of industry-leading talent and world-class underwriting expertise from both companies, as well as meaningful transaction synergies,” Mr. Charman said.

“Despite our repeated attempts since late January to engage in confidential and friendly discussions, Aspen's board and management have rebuffed our proposal and refused to engage with us, thereby denying Aspen's shareholders the ability to understand and attain the clear financial, operational, and strategic benefits of this transaction. We are fully committed to this transaction and are confident that Aspen's shareholders will recognize the value of our proposal and actively encourage their board to begin constructive discussions with Endurance without delay, with the goal of reaching a negotiated transaction,” Mr. Charman added.

Mr. Charman concluded, “Endurance shareholders will also significantly benefit from bringing these two leading companies together. Reflecting my own deep conviction about the future of Endurance and the benefits of the combination, I will purchase $25 million of Endurance common shares in connection with this transaction in addition to the $30 million of personal capital I have already invested in Endurance.”

Aspen's board of directors has rejected the Endurance proposal.

In a statement, Glyn Jones, chairman of the Aspen board of directors, said, “After careful review and deliberation, the board of directors unanimously determined that Endurance's proposal is not in the best interests of Aspen or its shareholders. Endurance's ill-conceived proposal undervalues our company, represents a strategic mismatch, carries significant execution risk, and would result in substantial dis-synergies. Furthermore, most of the consideration to Aspen shareholders would be in a stock that would reflect these problems.

“Aspen has a proven track record of performance and a clear strategy to increase shareholder value. Endurance has a mixed operating track record, new leadership, an unproven strategy, and no experience with large acquisitions. Moreover, this transaction would be highly disruptive to Aspen's corporate culture, which has proven to be a significant competitive advantage in the marketplace.”

In making its determination, the Aspen board said that it considered, among other factors, the following:

- Aspen is executing a clear strategy to deliver superior value for shareholders, while Endurance's proposal undervalues the company and carries significant risks.

- A combination would burden Aspen with Endurance's unproven underwriting teams with no clear strategy; an unprofitable insurance business; and a volatile and challenged crop business.

- Endurance has shown a public disdain for Lloyd's, which is the growth engine of Aspen's well-established international insurance business.

- Endurance has a mixed operating track record, no experience with large acquisitions, new leadership and an unproven strategy.

- The proposed transaction jeopardizes Aspen's corporate culture, which Aspen believes is a significant component of its franchise value because it differentiates Aspen with clients and allows Aspen to recruit and retain outstanding professionals.

- The disruption of market and underwriting relationships likely would result in material loss of business.

- The proposal involves a number of substantial execution risks, including financing uncertainty, due diligence outcome, regulatory approvals, the need for favorable votes by the shareholders of both companies, and integration risk.

Endurance commented on Aspen's rejection. “That's a lot of value to leave on the table,” said Endurance Chairman and CEO Charman. “Cut through the rhetoric, and this transaction is all about value and the fact that Aspen shareholders are being denied the opportunity to realize that value. We believe shareholders will see the limitations of the Aspen 'go-it-alone' plan, which they have been pursuing unsuccessfully, and will recognize the value of the transaction we are proposing – and, in so doing, will make their views known to the Aspen board of directors.”

Endurance's financial advisors in connection with the proposed transaction are Morgan Stanley & Co. LLC and Jefferies LLC, and its legal counsel is Skadden, Arps, Slate, Meagher & Flom LLP and ASW Law Limited.

Goldman, Sachs & Co. is acting as financial advisor and Wachtell, Lipton, Rosen & Katz and Willkie Farr & Gallagher LLP are acting as legal advisors to Aspen.