The heads of General Motors , Canadian auto parts group Magna and its Russian partner Sberbank are due to meet on Thursday ahead of GM's board meeting on Friday, a German newspaper said.

German tabloid Bild reported in its Thursday edition, citing sources close to the negotiations, that Sberbank's Chief Executive German Gref will join GM CEO Fritz Henderson and Magna's co-CEO Siegfried Wolf for the first time at a meeting in Detroit later in the day.

Magna and Sberbank have teamed up to bid for GM's European Opel business, rivaling an offer by RHJ International , and sources close to the deal have told Reuters that GM's board of directors will convene on Friday to address among other things the sale of Opel.

The purpose of Thursday's meeting in Detroit is for all parties to get to know each other better and not to hold fresh negotiations, Bild said.

Sources close to the talks have said the GM board aimed to recommend one of the suitors at Friday's meeting.

Trustees who oversee a majority stake in Opel -- which was ring fenced and propped up with German aid in May to avoid being swept into GM's brief bankruptcy -- must approve any decision.

(Reporting by Eva Kuehnen; Editing by Hans Peters)