Top 200 US firm Armstrong Teasdale has expanded into the UK with the acquisition of London-based Kerman & Co, its first office outside of its home country.

The acquisition adds more than 50 lawyers to Armstrong Teasdale’s roster, boosting its fee-earner headcount to roughly 340 and a support staff of more than 300.

Armstrong Teasdale sits at 177 in the Am Law 200 and while the majority of Am Law 100 law firms have substantial offices in London, few firms of its size have ventured across the Atlantic.

David Braswell, Armstrong Teasdale’s managing partner, said: “We have long served clients around the world. The growth opportunity in London is tremendous, and it quickly became clear in conversations that Kerman & Co’s goals were well-aligned with Armstrong Teasdale’s strategic vision.”

Kerman & Co, which is based in The Strand in London's West End, ranks its specialisms as M&A, capital markets, sport and private client services, as well as offering expertise in IP, litigation, employment, immigration and real estate.

It achieves several rankings in the Legal 500 directory for mid-market work, including M&A deals up to £50m. The deal sees the UK firm's co-founder and managing partner, Daniel O’Connell, become head of Europe at Armstrong Teasdale with a brief to ‘lead the execution of strategic growth for the firm in Europe’.

He said: “We are excited about the opportunity to chart a new path for the firm in London, as well as broaden the offering we can provide to clients internationally. As you would imagine, this is not an opportunity taken lightly, and it has been carefully considered over a period of time. We are very much looking forward to further developing our London office, whilst building a strong bridge into Europe under the Armstrong Teasdale brand.”

The 120-year-old Armstrong Teasdale has 12 offices across the US, most recently opening in Delaware last month. It is headquartered in St. Louis and also has a presence in New York and Las Vegas.

According data published by Law.com, Armstrong Teasdale recorded revenue of $136.9m against profits per equity partner of $615k in 2019.

Other US firms of comparable size with a significant presence in London  include litigation specialists Kobre King, which sits at 160 in the Am Law 200 ranking, and Curtis (183), which has had a London office since the mid-1970s and offers UK and US law advice across a range of practice areas, including corporate, projects and litigation.