The board of General Motors Co has opted to keep Opel, sources briefed on the deliberations said on Tuesday, undoing months of painstaking negotiations to sell the European unit to a Russian-backed group led by Canada's Magna .

GM's 13-member board was meeting on Tuesday in Detroit.

The meeting of the board came after European Union officials asked GM to confirm that it would have decided to sell Opel to Magna if it had known that 4.5 billion euros ($6.58 billion) in state aid promised by Germany would go to any buyer.

GM had no immediate comment. The sources with knowledge of the GM board deliberations could not be identified because the decision has not been announced.