Dual Group, the underwriting arm of London-based brokerage Howden Group Holdings Ltd., on Thursday agreed to acquire Align Financial Holdings, a San Diego-based general agency and underwriting management group, for $800 million.

The deal will create an international underwriting group with over $2 billion in gross written premiums and 1,000 employees operating in 16 countries, according to a statement announcing the deal.

Kieran Sweeney, founder and CEO of Align, will lead the combined U.S. business, supported by Jim O’Connor, CEO of Dual North America Inc. and John Johnson, president of Align, the statement said.

Mr. Sweeney will also become executive chairman of Dual Group globally and a member of the Howden Group executive committee. 

Align, which has 290 employees in the U.S., all of whom will be joining Dual, writes over $630 million in gross written premium on an annualized basis through its commercial casualty, commercial property catastrophe, personal property and surety businesses.

Richard Clapham, CEO of Dual Group, said in an interview that the acquisition gives Dual a significant presence and scale in the U.S. market, creating “an operation writing over $1 billion in gross written premium in the U.S. in what is a $60 billion market.”

The deal also adds underwriting product expertise, Mr. Clapham said. “The scale of the combined businesses will open more doors to attracting new talent, new capacity, and enhancing data and analytical capabilities,” he said.

Align CEO Mr. Sweeney said once the deal is complete some 50% of the combined group’s business will come from the Americas, with the rest from Asia-Pacific, the United Kingdom, and continental Europe. Until now, Align has operated solely in the U.S.

The deal will give Align the “ability to cross-fertilize our expertise in the U.S. more as we gain a greater understanding of Dual’s international business,” he said.

“We’re a significant $200 million player in the property catastrophe space in the U.S. The analytics and modeling capabilities and technologies we have built are … highly leveragable across the combined operation,” Mr. Sweeney said.

The acquisition includes all four of Align’s general agency operating businesses: Align General Insurance Agency LLC, a casualty general insurance agency; Catalytic Risk Managers & Insurance Agency LLC, a property catastrophe program underwriting manager; Nalico General Agency, Inc., a specialty personal property underwriter; and its surety business, Deposit Choice; as well as its claims adjusting firms Align Claims Services Inc. and Catalytic Claims Services Inc.

Subject to regulatory approval, the transaction is scheduled to be completed Oct. 1.