Herbert Smith is set to lose a second US securities partner to Morrison & Foerster (MoFo) in Hong Kong, marking the fourth partner to leave the firm's US securities practice globally since the summer.

Melody Chen resigned from the UK firm in recent weeks and is set to join MoFo's Hong Kong office as a partner after serving out a notice period.

Chen was made up to partner at Herbert Smith in May this year and specialises in securities offerings, debt offerings as well as private equity investments, M&A, cross-border joint ventures and financings.

Her resignation marks the latest in a string of departures from the practice, taking the partner count in the US securities team from nine partners to five since July.

Asia head of US capital markets John Moore left the firm's Hong Kong office to join MoFo over the summer, while Jim Wickenden – the global head of Herbert Smith's capital markets practice – and Adam Wells, are set to leave the firm's City base to join Allen & Overy (A&O).

Herbert Smith has since appointed London-based US securities partner Steve Thierbach as global head of capital markets and Moscow-based CIS managing partner Allen Hanen as head of its US securities practice.

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. Both are still working at Herbert Smith.

Herbert Smith has seen a number of partner departures over the current year, including a three-partner Paris litigation team which resigned in June to join A&O.