Slaughter and May and Linklaters have advised on a joint venture deal between Centrica and Oslo-based oil and gas company Bayerngas Norge.
Centrica, the owner of British Gas, will combine its exploration and production (E&P) business with Bayerngas Norge to form a separate company with its own board.
The joint venture will comprise Centrica's assets in the UK, Netherlands and Norway and Bayerngas Norge's assets in the UK, Norway and Denmark.
Slaughters is acting for Centrica, with a London-based team including corporate transactions partner Hywel Davies, corporate finance partner Robert Innes, tax head Sara Luder, competition partner Lisa Wright, pensions and employment partner Sandeep Maudgil and intellectual property partner Duncan Blaikie.
The magic circle firm worked with lawyers from a number of its 'best friends' firms across Europe Denmark's Gorrissen Federspiel, Germany's Hengeler Mueller, NautaDutilh in the Netherlands and Norwegian law firm Schjodt.
Centrica will own 69% of the venture, while Bayerngas Norge's shareholders, who are led by Munich's municipal utilities company Stadtwerke Muenchen (SWM), will own the remaining 31%. It is understood that Linklaters is advising SWM.
The move, which remains subject to regulatory approval and is expected to close in the fourth quarter of the year, is hoped to lead to cost savings of 150m.
Centrica's legal function is led by group general counsel and company secretary Grant Dawson, who has held the role since the demerger of British Gas in February 1997.
The FTSE 100 company has historically worked with a variety of top UK firms, including Allen & Overy (A&O), Ashurst and Linklaters. In 2009, Linklaters and A&O both advised on its nuclear electricity joint venture with EDF.
Centrica group chief executive Iain Conn said: This joint venture creates a larger, more sustainable and more capable European E&P business and brings together like-minded shareholders who have a shared strategic vision on the role of E&P.