Charlie Geffen, the former senior partner of Ashurst and one of the pre-eminent private equity lawyers in London, is to join Gibson Dunn & Crutcher's London office along with fellow Ashurst corporate partner Mark Sperotto.

Geffen (pictured), whose next move had been the subject of intense year-long market speculation since he lost Ashurst's chairman election last October, is to join the US firm as it looks to build a corporate practice in the City.

For Gibson Dunn, the hire is internally viewed as the largest coup for the London office since the 2008 appointment of Lord Falconer, the former UK Chancellor and Justice Secretary.

Legal Week understands that Geffen, who resigned from Ashurst this morning, entertained roles both in and outside of private practice until recently.

Sperotto, who became an Ashurst partner in 2007, works in both mainstream cross-border and domestic M&A and private equity in both the City and the Italian markets.

He was touted as a replacement for former corporate head Stephen Lloyd, after the latter stepped down from the post in the wake of last year's chairman election, and later joined Allen & Overy (A&O).

Gibson Dunn is also understood to be in advanced discussions to hire another private equity partner from a separate firm.

Much of the speculation has focused on what marks something of a return to practice for Geffen, after several years in management, including the brokering of a major Anglo-Australian merger between Ashurst and Blake Dawson.

Prior to taking up the senior partner role in 2008, his list of clients included many of the largest names in the UK private equity funds industry, including Apax Partners, Cinven, Warburg Pincus and Blackstone.

At the time, Geffen was head of Ashurst's buyout team, having spent his entire career at the firm, joining as a trainee in 1982 and making partner nine years later.

Gibson Dunn's capture of a brand name private equity partner nonetheless marks a significant coup for the firm's practice in the City.

While boasting one of the leading private equity practices in the US, the firm has not made the same splash in the practice as leading transatlantic buyout teams at Simpson Thacher, Weil Gotshal & Manges and Kirkland & Ellis.

"It's a great firm, but its reputation in the UK has primarily been built on litigation," commented one senior private equity partner, who told Legal Week he had "been taken to school by Charlie on several occasions" when working opposite the former Ashurst leader on deals.

"They've really managed to slowly turn that aircraft around in the last couple of years, and are starting to make some smart investments."

Earlier this year, Gibson Dunn hired two Ashurst corporate partners in as many months, with Jonathan Earle and Nigel Stacey both moving to the firm this summer.

The Ashurst men were the latest in a string of exits from the UK firm's corporate team, including private equity partner Karan Dinamani, who left the firm in March to join Stephen Lloyd at A&O.

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