U.S.-headquartered law firms in London hired nearly twice as many partners from other U.S. law firms as they did from their U.K. competitors in 2019, Legal Week analysis of lateral hire data has found.

In total, nearly 30% of all lateral partner hires in London involved U.S partners defecting to other U.S rivals.

Key examples included mass partner moves from Squire Patton Boggs to Crowell & Moring while Akin Gump also hired a raft of partners from fellow U.S. firms Weil Gotshal & Manges, White & Case, O'Melveny & Myers and Orrick, Herrington & Sutcliffe.

Other notable U.S. to U.S transfers in the capital have included hires by Kirkland & Ellis' of Andrew Shore and David Irvine from Proskauer Rose and Weil respectively, while Kirkland in turn lost private equity duo partner David Arnold and Gavin Gordon to Willkie Farr & Gallagher.

The data, which was compiled using ALM's intelligence arm, Legal Compass, and reporting by Legal Week across the year, identified nearly 340 lateral partner hires in London by Am Law 100 and UK Top 50 firms.

Across the year, U.S.-based firms comprised seven of the top 10 lateral hirers, but also five of the top 10 targets, with the data suggesting growing inter-competition between U.S firms to build up their London offices.

"It's going to be more of the same next year," said Seamus Hoar, a partner at legal recruiter Major Lindsey & Africa.

"It's the intention of the US firms is to continue to grow – and a lot of them have had spectacularly good years."

Moves from U.K firms to U.S firms were only marginally higher than the other way round – the former accounting for 13% of moves compared to the latter on 11%.

The U.S. threat was still potent however. The Magic Circle lost eleven partners in lateral moves this year, ten of whom moved to U.S firms. These included Freshfields Bruckhaus Deringer's Adrian Maguire to Kirkland & Ellis, Linklaters' Victoria Sander to Latham & Watkins and David Avery-Gee to Weil.

The one exception to this was Allen & Overy's Michael Castle, who joined Deloitte Legal.

Despite the hire of Castle, the Big Four had a very quiet recruitment year overall, gaining just five partners – almost exclusively from U.S. firms – while losing four partners to other law firms.

"Next year is going to be a busy lateral market – all the indicators are that it will continue to grow," Hoar told Legal Week.

"In my 25 years, it's the most active in terms of people talking about moving."