Bingham McCutchen is to lose its most senior London litigation partner, Neil Micklethwaite.

Micklethwaite, who joined Bingham in November 2004 from legacy firm DLA, is leaving to set up a niche firm with former Gouldens colleague Roger Gherson.

The pair will work in Gherson's immigration boutique, Gherson & Co, which will rebrand in September as simply Gherson.

The duo will initially be the only equity partners at the firm, which will focus on litigation and regulation alongside immigration and human rights work. However, they are in the process of hiring two more litigation partners and expect to have around 20 fee earners when the firm relaunches.

Micklethwaite's practice focuses on cross-border investigations of businesses affected by fraud and corporate failures. He advised on the investigations of companies including Guinness, Enron and TXU Europe. In addition, he gives asset protection advice to foreign companies – particularly in Russia and the Middle East – and high net worth individuals. He recently represented biotech entrepreneur Sir Christopher Evans in the high-profile cash-for-honours enquiry.

Micklethwaite told Legal Week: "Human rights work – which will primarily involve preventing the confiscation of property assets – will be an important area, but the core of the firm will be complex litigation."

Gherson added: "I have been trying to convince Neil to join with me for many years. We share a very similar view of how the market is developing and both of us have strong client connections in the main emerging economies and with international businessmen operating in London."

Micklethwaite's decision to leave Bingham comes four months after finance partner Sarah Coucher quit for DLA Piper. The departures leave the US law firm with 11 partners in London, including litigation partner Natasha Harrison.