The Opel Trust board, which controls a 65 percent stake in Opel and has the final word on who can acquire the carmaker, is split on General Motors' plan to sell the unit to a group led by Canada's Magna, a German government source said on Thursday.

The talks are dragging on because there is a split on the board, the government source familiar with the talks told Reuters, adding that the start of an Opel Trust news conference originally planned for 1415 GMT had therefore been delayed.

The Opel Trust board comprises five people, two each from GM and the German federal and state governments, as well as an independent chairman who is supposed to act as an arbiter between the two sides, though he has no vote.

 (Reporting by Markus Wacket, writing by Paul Carrel)