Eversheds International has won a €10bn (£9.3bn) mandate advising on Hungarian aspects of the high-profile South Stream pipeline project that is set to bring gas from the Caspian Sea region to Europe.

Sandor Szegedi Szent-Ivany Komaromi Eversheds, the Hungarian member of Eversheds International, was appointed to advise the Hungarian Development Bank on negotiations with Russia's state-controlled gas supplier Gazprom to set up a joint venture to build the Hungarian leg of the pipeline.

Eversheds International Hungarian managing partner Tamas Sandor took the lead for the Hungarian Development Bank, assisted by corporate partner Peter Komaromi. Hogan & Hartson's London managing partner Gary Pegg advised Gazprom and will continue to advise as the company signs similar joint ventures in each country the 3,000km pipeline is expected to run through.

Sandor said: "This is the first step in building a new natural gas pipeline and a monumental agreement for European energy supplies."

The deal closed on 10 March and was signed in the presence of Russian Prime Minister Vladimir Putin and Hungarian Prime Minister Ferenc Gyurcsany. The deal has generated work for European firms, including Bonelli Erede Pappalardo and Wolf Theiss, advising on local aspects of the pipeline