Simpson Thacher & Bartlett has hired Clifford Chance (CC) M&A partner Amy Mahon for its London office, in the latest departure from the magic circle firm to US rivals.

Mahon, who has been a partner at CC since 2008, specialises in UK and cross-border M&A, leveraged buyouts, infrastructure and consortium transactions on behalf of financial sponsors including private equity firms, infrastructure funds and investment banks.

The move comes after a series of exits from the magic circle firm's corporate department to US firms in the City, including CC infrastructure M&A head Brendan Moylan, who moved to Latham & Watkins in the summer.

Simpson Thacher London managing partner Jason Glover – himself a former CC partner – said: “Amy is a perfect fit for our London team, having already worked on a number of market-leading transactions on behalf of longstanding Simpson Thacher private equity clients.

“Her impressive track record as a top M&A practitioner will further bolster our global M&A capabilities and add additional depth to our bench of exceptionally skilled London-based lawyers.”

Glover joined Simpson Thacher in 2010 to launch a City funds practice for the US firm, a year after corporate heavyweight Adam Signy also moved over.

Mahon added: “I am thrilled to have the opportunity to join the Simpson Thacher team and work with an outstanding group of lawyers, who represent market-leading clients on some of the most sophisticated transactions in the global M&A market.”

Mahon was listed as an M&A rising star by Legal Week in 2015 and was recently part of a CC team that advised EQT on Apax Partners’ $2bn sale of chemicals distribution company Azelis.

Other key deals she has worked on have included advising a consortium comprising CDPQ and Hermes on its acquisition of a 40% equity stake in Eurostar International, as well as Apax, Permira and New Look’s dual-track exit and sale to Brait.

Other corporate exits from CC in the past few years have included M&A partners David Walker and Tom Evans, Africa specialist Kem Ihenacho, and German duo Oliver Felsenstein and Burc Hesse, all of who have joined Latham & Watkins, while white-collar crime partner Judith Seddon left to join Ropes & Gray as co-head of its London international risk practice this January.

A CC spokesperson said: "We would like to thank Amy for her contribution to the firm and wish her well for the future."

• For more, see 'It’s not about egos' – CC's private equity practice looks to shape up after recent exits