Sullivan & Cromwell has ended its long hunt for a UK corporate partner after recruiting Allen & Overy (A&O) partner Vanessa Blackmore.

Blackmore, who is expected to join after the summer, will be the elite Wall Street firm's third UK partner and the first with equity capital markets and M&A experience, as partners Jamie Logie and Craig Jones both focus on finance work.

Blackmore will work across a range of areas, including equity and debt capital markets, M&A and corporate restructurings, in a move that finally takes Sullivan into the City corporate market.

Sullivan London head William Plapinger told Legal Week: "She brings a very versatile practice, and that is very important for us as we are not as specialised as the magic circle firms. We have seen a rising demand from clients to provide the advice that Vanessa can give."

Sullivan voted on the appointment late last week and is expecting to add further English law associates to work with Blackmore, who has been a partner at A&O since 1999. The US firm rarely makes lateral hires and, according to Plapinger, still intends to build its UK-law practice largely through organic growth rather than lateral partner appointments.

The move ends a prolonged hunt by Sullivan for a UK corporate partner. The firm was known to be eager to replicate its success in Paris, where Sullivan has scooped up lucrative work with a lean practice staffed by lawyers like former Clifford Chance rainmaker Dominique Bompoint, who joined the US firm in late 2004.

The entry of one of American's top firms into the City corporate market will be watched warily by London firms coming after three years in which Sullivan was acknowledged to have made substantial in-roads in the European deal market.

Blackmore's departure is also the latest in a stream of defections from A&O to US firms in London. In recent weeks, finance partner Stephen Gillespie has resigned to join Kirkland & Ellis and corporate partner Michael McDonald quit to join Cleary Gottlieb Steen & Hamilton.

Other losses over the last 12 months include Tony Keal, who joined Simpson Thacher & Bartlett, Clive Wells, who left for Skadden Arps Slate Meagher & Flom, and Julian Tucker, who left for Shearman & Sterling.