Herbert Smith is set to lose two US-qualified capital markets partners to Allen & Overy (A&O), with the forthcoming departure of Jim Wickenden and Adam Wells marking the latest in a string of partner exits from the City firm.

Wickenden – the global head of Herbert Smith's capital markets practice – and Wells both handed in their notice in recent weeks and are set to join A&O after serving a notice period.

Both hires have been voted through by A&O; however, their exit terms remain under discussion.

Wickenden has been a partner at Herbert Smith since 1999 when he joined from JP Morgan, where he was EMEA head of legal and compliance.

Wells, meanwhile, was promoted to partner at Herbert Smith in 2007, having previously worked in the New York and London offices of Davis Polk & Wardwell.

In a statement, Herbert Smith said that Allen Hanen (pictured), – the firm's CIS managing partner, would now head up the global US securities practice, while the London-based US team will continue to be led by partners Steve Thierbach and Alex Bafi.

Herbert Smith global head of corporate James Palmer said: "We wish Jim and Adam success in their future endeavours. Steve and Alex are both experienced capital markets practitioners and have acted on a wide range of matters in numerous jurisdictions.

"We are very confident in the depth of our team and in the ongoing success of this practice: this confidence is further enhanced by the quality of the associates in the practice."

David Krischer, A&O's global head of international capital markets, commented: "Jim and Adam are the perfect complement to our international capital markets practice, combining their senior equity capital markets expertise with our debt capital markets and corporate coverage."

News of the departures comes after Herbert Smith's Asia head of US capital markets, John Moore, quit to join the Hong Kong office of Morrison & Foerster over the summer.

Separately, a three-partner Paris litigation team also quit to join A&O in June this year and are still negotiating their start dates with A&O. Herbert Smith is able to hold equity partners to up to 12 months' notice.

At A&O, City partner hires have been a rare occurrence for the firm in recent years. Last year the firm added just two London laterals, with energy partners John Geraghty and Paul Griffin joining, also from Herbert Smith.

The magic circle firm's most recent hire of a US-qualified partner in London was that of high-yield specialist partner Kevin Muzilla, who joined from the London office of Milbank Tweed Hadley & McCloy in 2009.

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