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 partners Hywel Davies and 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 firms across Europe, including Denmark's Gorrissen Federspiel, Germany's Hengeler Mueller, NautaDutilh in the Netherlands and Norwegian law firm Schjodt.

Centrica will own 69% of the joint venture, while Bayerngas Norge's shareholders, who are led by Munich's municipal utilities company Stadtwerke Muenchen (SWM), will own the remaining 31%. Linklaters is advising SWM with a team led by corporate partner Nick Garland and projects partner Mark Russell.

Innes commented: "This was a deal where you had two companies combining their businesses, and that creates complexity. When you are entering a joint venture, each company is used to controlling their business and there are intricacies around the right level of control when there is an equity split.

"Hengeler know the jurisdiction well, and were very involved in getting us up to speed on the counter-party. Centrica has used Schjodt regularly in the past and were keen to use them on this – working with them fits well with our flexible model for using overseas firms; we took Centrica's advice and were happy to do so."

The deal, 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."