FRANKFURT (Reuters) – Germany has put Russian oil group Rosneft’s planned purchase of a 37.5% stake in the PCK Schwedt refinery under review, a spokesperson for the economy ministry said on Monday. “Concerning the takeover of additional shares in the PCK (Schwedt) refinery by Rosneft, an investment review process has been launched,” the spokesperson said in response to an enquiry. The deal, agreed in November, would raise Rosneft’s stake in the east German refinery to 91.67%, with Italy’s Eni holding 8.33%. Germany has launched such reviews in the past when it has considered there were grounds…