US law firm Kirkland & Ellis has overtaken Latham & Watkins as the world's richest law firm, data from US legal media company ALM shows.
The firm, which has its City headquarters in the Gherkin, grew its revenue by 19 per cent last year to $3.165bn (£2.24bn).
This puts it ahead of rival Latham, currently embroiled in a sex scandal, which became the first law firm in the world to break the $3bn barrier this year, with revenue of $3.065bn, ALM data showed.
The report said that the firm's London office, which has expanded rapidly in recent years, accounts for $316.5m, around 10 per cent of total revenue.
In London Kirkland has moved to challenge the "magic circle", the five UK-headquartered law firms that traditionally dominated the City legal market.
Kirkland's profit per partner this year stands at $4.7m (£3.32m), easily outstripping magic circle firms such as Freshfields Bruckhaus Deringer on £1.547m, Linklaters on £1.568m and Allen & Overy on £1.51m.
That profitability has allowed Kirkland to expand aggressively in the London market, hiring trophy partners from the magic circle.
In December Freshfields private equity heavyweight David Higgins quit the firm to join Kirkland on a reported $10m a year salary.
The firm had previously hired Linklaters rising private equity stars David Holdsworth, Roger Johnson and Stuart Boyd as it makes a big push into London's legal private equity space.
Other key hires include competition partner Paula Riedel who joined from Linklaters and restructuring partner Sean Lacey and debt finance partner Jonathan Birks who joined from Freshfields.
London is now the firm's third largest office with 230 lawyers, around 10 per cent of the firm's total headcount.
Kirkland does not officially release revenue or profit numbers and declined to comment on the figures.
Its US rival Latham is currently in the midst of a sex scandal after its chair Bill Voge quit the firm this week after "sexting" a woman he had contacted through a Christian outreach programme.