Poland's Unimot S.A. (WSE:UNT) has emerged as one of the possible buyers of a 37.5% stake oil major Shell plc LSE:SHEL) owns in Germany's PCK Raffinerie GmbH, two people familiar with the matter said. The refinery, which is majority-owned by Russia's Rosneft (ROSN.MM), has been a problem for the German government ever since Berlin ended its energy ties with Moscow last year. As a result, Germany put Rosneft's 54.17% stake under trusteeship, essentially giving the government control over the asset while technically leaving ownership in the Russian group's hands.