A wholly owned subsidiary of Japan’s Sompo International Holdings has reached a definitive agreement to acquire Aspen Insurance for an aggregate consideration of around $3.5bn (£2.59bn). 

The transaction will involve Sompo purchasing all the issued Class A ordinary shares of Aspen at $37.50 each, in cash. 

The price marks a 35.6% premium to Aspen’s unaffected share price on 19 August 2025.  

Sompo anticipates significant cost and capital synergies from the acquisition and expects the deal to be “immediately accretive” to return on equity upon completion. 

Aspen Insurance, with operations spanning Bermuda, Canada, Singapore, Switzerland, the UK and the US, is known for its specialty insurance and reinsurance offerings.  

The company focuses on specialty lines including cyber, credit, political risk and various forms of property and liability insurance. 

It also specialises in casualty reinsurance, property catastrophe reinsurance and specialty reinsurance, with its Lloyd’s syndicate offering access to “complex risks” as well as reinsurance licensing across untapped markets. 

In 2024, the company reported annual gross written premiums of $4.6bn. 

Sompo believes that the acquisition will improve the diversification of its portfolio, widen revenue streams and bolster its financial profile.  

The insurer plans to integrate Aspen with its overseas insurance operations and drive further expansion across developed markets. 

Additionally, Aspen’s involvement in the alternative reinsurance market through its Aspen Capital Markets platform is seen as a potential asset for Sompo, allowing for improved capital management and risk exposure strategies. 

The deal is expected to be finalised in the first half of 2026, contingent on regulatory approvals and standard closing conditions.  

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

“We look forward to welcoming the team from Aspen as we bring our organisations together, recognising that the property/casualty market continues to value platforms that can underwrite and manage capital and risk at scale – and with exceptional skill.” 

Aspen Group executive chairman and Group CEO Mark Cloutier stated: “This transaction represents an excellent outcome for Aspen and our shareholders, while Sompo’s scale and capital strength will create significant opportunities for our customers, trading partners and colleagues.”  

Aspen returned to the public market earlier this year. The company first went public on the New York Stock Exchange in 2003 and added a secondary listing on the Bermuda Stock Exchange in 2004.  

Its shares were traded on both exchanges until 2019, when Apollo acquired the company for $2.6bn.