Japanese insurer Sompo Holdings unveiled a landmark deal Wednesday to acquire Aspen Insurance Holdings Ltd. in a transaction valued at $3.5 billion in cash. The agreement, unanimously approved by both companies’ boards, will see Aspen shareholders receive $37.50 per Class A share—a 35.6% premium over its unaffected price of $27.66 on Aug. 19.

Aspen’s stock surged nearly 14% on the news by Wednesday afternoon, signaling investor enthusiasm for the deal.

Strategic Expansion at the Right Market Moment

The acquisition, slated to close in the first half of 2026 pending regulatory approvals, is being executed through Sompo P&C, the insurer’s property and casualty arm.

“Strategic acquisitions have been a key part of our growth plan to build a robust and diversified global P&C platform, and Aspen represents an excellent opportunity at the right time in the market cycle,” said James Shea, CEO of Sompo P&C.

Aspen, which only went public last year, generates over $4.6 billion in annual gross written premiums across operations in the U.S., U.K., Canada, Singapore, and Switzerland.

Aspen’s Journey: From Apollo to Sompo

Aspen remains majority-owned by Apollo Global Management, which purchased the company in 2019 for $2.6 billion. Earlier this year, Aspen re-listed on the New York Stock Exchange, raising $397.5 million through the sale of 13.25 million shares at $30 each.

For Sompo, the acquisition not only enhances its property and casualty footprint but also deepens its specialty and reinsurance capabilities in cyber, credit and political risk, inland marine, U.K. property and construction, and U.S. management liability.

The deal also secures Sompo entry into Aspen Capital Markets, which manages more than $2 billion in third-party capital.

Leadership Praise and Strategic Alignment

“Aspen is a highly regarded brand, and through this process it has become clear that they represent a long-term owner for Aspen that respects our business and shares our values and ethos,” said Mark Cloutier, Aspen Group executive chair and Group CEO.

The Advisors Behind the Deal

Legal advisers for the deal include:

• Skadden Arps Slate Meagher & Flom LLP, representing Sompo, with a team led by partners Todd Freed, Patrick Lewis, Joseph Penko, Dwight Yoo, Danielle Li, Jared Binstock, Kenneth Schwartz, David Schwartz, and Oren Epstein.

• Sidley Austin LLP, advising Aspen, with partners Sean Carney, Jonathan Blackburn, David Perkins, and Jessica Day.

On the financial side, Morgan Stanley is advising Sompo, while Goldman Sachs and Insurance Advisory Partners are working with Aspen.

A Defining Move in the Insurance Landscape

The Sompo to acquire Aspenl deal marks a defining moment in the global insurance industry, combining Japanese financial power with Aspen’s international specialty and reinsurance expertise. If successful, the acquisition will reshape Sompo’s presence worldwide and intensify competition in the high-stakes world of global risk management.