Dusseldorf - E. ON, one of Germany's biggest energy companies, said Thursday it had bought one quarter of the one of the world's greatest natural gas fields, at Yuzhno Russkoye in Russia.
The deal, which follows years of tortuous negotiations, was signed with gas monopoly Gazprom at a meeting of Russian and German government leaders on Thursday in the Russian city of St Petersburg.
Another big German company, BASF, has already bought a quarter of the same field.
E. ON controls a large part of Germany's gas and electricity supplies.