Sullivan & Cromwell, Baker & McKenzie and Akin Gump Strauss Hauer & Feld have advised on BP's $7.1bn (£4.6bn) sale of a majority stake in Argentinian energy company Pan American Energy.

Akin Gump was instructed by Argentina-based energy company Bridas Corporation, which is acquiring a 60% stake in Pan American. The US firm's team was led by London partner-in-charge Steven Blakeley and Dallas corporate partner Seth Molay.

China National Offshore Oil Corporation (CNOOC), Bridas' state-owned Chinese parent company, was advised by longstanding adviser Bakers, which fielded a team led by Shanghai-based corporate partner Bee Chun Boo.

Both Akin Gump and Bakers also advised on CNOOC's acquisition of a half share in Bridas for approximately $3.1bn (£2bn) earlier this year.

BP, meanwhile, instructed Sullivan & Cromwell, with the US firm fielding a team led by London-based finance partner Stewart Robertson.

Akin global corporate head Rick Burdick commented: "This is the second significant deal for the firm advising Bridas this year. The two transactions illustrate our strengths internationally."

He added: "Both are transformational deals in the energy sector and capitalise on our comprehensive understanding of the industry globally."

The sale is a part of BP's aims to divest $30bn (£19.3bn) in assets by the end of next year to boost its balance sheet in the wake of the oil spill. The energy giant has already sold $20bn (£12.9bn) in assets since announcing its plans in July.

Pan American is considered the second-largest oil and natural gas producer in Argentina, according to BP. The deal is expected to close by mid-2011.