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.