Under the deal, a wholly owned subsidiary of Sompo International Holdings has acquired 100% of Aspen's issued class A ordinary shares. Aspen's class A stock has ceased trading on the New York Stock Exchange following the completion of the merger, while its preference shares will remain outstanding with their rights, terms and conditions unchanged and will continue to be listed. Sompo and Aspen may in future consider redeeming, repurchasing or delisting the preferred shares or associated depositary shares.
The deal, which was initially announced in August 2025, has a value of about $3.5 billion and represents a roughly 35% to 36% premium to the company's unaffected share price and about 1.3x tangible book value at announcement.
Following completion, Aspen comes under the Sompo Group umbrella and will transition to trading under the Sompo brand. Mark Cloutier, who led Aspen through its turnaround and sale process, will move into an advisory role with Sompo.
Strategic fit: specialty, reinsurance, and alternative capital
The deal brings Sompo a broader set of specialty and reinsurance capabilities.
Aspen wrote $4.6 billion of gross written premium in 2024 across its insurance and reinsurance franchises, reporting a combined ratio of 87.9% and an operating return on equity of 19.4% for the year. Its portfolio spans financial and professional lines, casualty, specialty and first-party business.
The company also adds Aspen Capital Markets (ACM), an alternative capital platform managing more than $2 billion in third‑party assets, with the majority of 2024 fee income generated from non‑catastrophe, longer‑tail lines. Sompo has identified ACM as a key attraction, expecting it to enhance its capital‑management options and provide more flexibility in handling risk and earnings volatility.
At Lloyd’s, Aspen Syndicate 4711 reported around £1.0 billion of gross written premium and an 82‑range combined ratio for 2024, with growth across specialty, financial and professional lines, and casualty. That Lloyd’s platform gives Sompo International additional capacity and distribution in London for complex specialty and reinsurance risks.
Sompo’s overseas growth agenda
Group CEO Mikio Okumura said the acquisition is an important step in Sompo’s strategy to build a more diversified property and casualty platform.
“Today marks an important milestone in our strategy to continue Sompo’s plans for profitable growth, to deploy capital strategically and to ensure a globally diversified Property & Casualty (P&C) platform. I am pleased to welcome the Aspen team to Sompo,” Okumura said.
Sompo has been using overseas M&A to help meet targets under its mid‑term management plan, which aims to lift adjusted consolidated ROE into the mid‑teens and increase the contribution from international business. The group previously bought Endurance Specialty Holdings in 2017 and has since consolidated its international P&C operations under Sompo International.
James Shea, CEO of Sompo P&C, said the Aspen deal reinforces the group’s commitment to growing its international footprint through the cycle.
“This transaction continues our commitment to invest in and grow our global P&C footprint through market cycles. The addition of Aspen’s reinsurance and insurance portfolios along with a more substantial presence in the UK enable us to accelerate our commitments to our customers, people and shareholders,” Shea said. “We look forward to welcoming our new colleagues and continuing to build our global portfolio through investments in people and technology. Aspen’s culture of underwriting and customer focus will ensure a smooth transition as we engage as one organization with our customers and partners.”
Integration and market implications
Aspen has undergone significant restructuring in recent years under Apollo Global's ownership. Those changes mean Sompo is acquiring a business that is already reporting stronger results, but integration will still be closely watched.
Key execution questions for Sompo include how quickly it can align underwriting appetites, operating platforms, and capital structures across Sompo International and Aspen, and how it uses Aspen’s alternative capital and Lloyd’s capabilities without disrupting existing portfolios.
