ST PETERSBURG, Russia, Nov 10 (Reuters) - Sberbank (SBER03.MM: Quote, Profile, Research) Chief Executive German Gref said on Tuesday he did not rule out legal action against General Motors [GM.UL] after the carmaker's U-turn on selling its Opel unit.

"If necessary, we are prepared to defend our position in court. Lawyers are studying the possibility but we have every chance of avoiding the courts," Gref told reporters.

GM reversed its decision to sell a majority stake in Opel to a consortium including Sberbank, Russia's biggest lender, and Canadian auto parts business Magna International (MGa.TO: Quote, Profile, Research), opting instead to restructure the European carmaker. (Reporting by Denis Pinchuk, writing by Robin Paxton; editing by Maria Kiselyova)