The German subsidiary of Russian oil giant Rosneft was placed under trusteeship on Friday, giving Germany's federal regulator control of the PCK refinery in Schwedt, a key source of fuel for the city of Berlin.

The U.S. is weighing whether to sanction Russia's biggest oil producer, Rosneft. for maintaining ties with Venezuela's Nicolas Maduro, though American officials are wary that the move could cause chaos in global oil markets, according to people familiar with the matter.