New York firm Dewey Ballantine has hired Nabarro Nathanson's star partner Mark Saunders as part of a drive to double its London staff in the next 18 months.
Saunders, who headed Nabarro's energy group, is a specialist in energy, oil and gas work.
He is the fourth UK partner to join the firm's London office.
Dewey Ballantine is also looking to recruit a minimum of three or four more project finance partners and a tax partner during the next few months, and will primarily be looking for candidates from the top 10 City firms.
Moni Mannings, a partner at the firm said: "We are very anxious to make sure that we have a
50:50 split of US lawyers and English lawyers.
"The appointment of Mark Saunders brings the number of British partners to four, balancing out our five American partners."
Dewey Ballantine is also working on developing its presence in Eastern Europe, where it has firms in Prague, Budapest, and Warsaw.
Dewey Ballantine signalled its intentions to build a significant London practice in 1996 when it ended its alliance with Theodore Goddard.
Mannings joined the firm from Simmons & Simmons in 1997 when she was assigned the task of setting up a banking team.