Willkie Farr & Gallagher boosted London revenues by almost 50% during 2017, a year in which the US firm posted record results across all key financial metrics.

The City office generated $53m (£38m) in revenue over the calendar year, up 47% from $36m (£26m) in 2016, the firm said. The London base has more than 50 lawyers focused on compliance and enforcement, insurance, asset management, restructuring, private equity and competition.

Recent high-profile mandates have included advising Barclays on fraud charges brought by the Serious Fraud Office relating to the bank’s capital raising arrangements with Qatari investors during the 2008 financial crisis.

The firm also recently bolstered its London partnership ranks with the hire of Slaughter and May associate Simon Osborn-King, who is joining as a partner after more than 10 years at the magic circle firm.

Firmwide revenues rose nearly 12% to $772m (£548m) during 2017, while profit per equity partner rose 13% to $2.97m (£2.1m) and revenue per lawyer (RPL) rose 5% to $1.2m (£852,000), according to preliminary ALM reporting.

The firm increased its profitability even as it boosted its size, with total lawyer headcount rising 6% to 644 lawyers. The firm’s equity partnership ranks increased by three to 145.

Gartner said private equity and M&A work were key drivers of the growth, but litigation, restructuring and asset management were also “big contributors.” As well as London, he said there was substantial contributions from the firm’s Frankfurt and Paris offices.

Fresh off the record results, Willkie Farr has added a string of partners in the first quarter of 2017.