Shearman & Sterling is losing high-profile M&A partner Jonathan Coppin to US rival Hogan & Hartson.

Shearman announced his departure internally today. He will become the second corporate partner to leave Shearman's London office in recent months following Adrian Knight's move to Skadden Arps Slate Meagher & Flom in November last year.

Coppin joined Shearman in November 2002 from Norton Rose. He focuses on domestic and cross-border M&A and has been involved in deals including last month's £13.6bn tie-up between the Nokia and Siemens communication services businesses, in which he advised Nokia.

In recent years he has advised on the £2.3bn sale of 11.5% of Standard Chartered to Temasek, AXA's £3.5bn offer for Guardian Royal Exchange and TXU's £4.5bn bid for the Energy Group.

A Shearman spokesperson said: "Jonathan has been offered an opportunity to develop a new practice on a greenfield site and felt that he needed a new challenge after being part of our well-established, integrated US and English law M&A team, which has grown to 25 lawyers and has developed a premier reputation in the London market."

Hogan also hired Lovells former competition head John Pheasant at the beginning of this year.