Kirkland & Ellis has been rocked by the resignations of London managing partner Stuart Mills and corporate partner Nigel Dunmore.
Mills, who was one of the two founding partners of Kirkland's London office in 1994, confirmed that he is retiring from the Chicago-based firm and returning to the US in order to "pursue other interests".
Dunmore, who previously headed up Kirkland's UK law group, also left the firm a fortnight ago in mysterious circumstances.
Kirkland London partner Jim Learner said it was not known where Dunmore had gone, but that he had left for "personal reasons".
The losses coincide with a massive hiring spree by Kirkland's London office, which included the appointments of former Linklaters private equity partners Graham White and Raymond McKeeve. Allen & Overy leveraged finance star Stephen Gillespie is also due to join Kirkland.
But both Learner and Mills denied speculation that the losses were related to the recent hires. Mills, a corporate M&A specialist, said he planned to retire from the law and work for his family's real estate investment company from North Carolina. He also plans to take on a director's role at one of Kirkland's publicly listed clients.
His replacement as London chief has not yet been decided, although Learner is understood to be the most likely candidate.