Canada's Magna on Monday inched closer to clinching its Opel buy with approval from Spanish plant workers as the clock ticks down to a November 3 board meeting at which GM is set to decide on the deal.

Spain's Opel workers voted to accept Magna's plans for the carmaker, after tense negotiations with labor representatives. Their decision clears away one of the last obstacles standing in the way of a deal from the European point of view.

General Motors' board of directors still needs to vote in favor of the deal and set European Union concerns over the politics of its choice of buyer to rest. It is due to make a decision at a regularly scheduled board meeting taking place next week.

Spain's unions had reached an initial agreement with Magna last week after the Canadian parts manufacturer agreed to keep the Figueruelas plant in northern Spain, which makes the Corsa, and to reduce proposed job cuts.

We decided to modify the plan Magna had for us, Ana Sanchez, one of the directors of CCOO, one of the two biggest unions at the Opel plant, told workers before the vote.

Also on Monday, Magna and its Russian partner Sberbank notified European Union antitrust regulators of their plan to buy a majority stake in the General Motors unit.

The European Commission set a November 27 deadline for it to decide whether to approve the takeover, according to its daily list of planned mergers under review.

The European Commission has been keeping a close eye on the transaction to ensure state aid is not misused for political purposes. Magna had won approval from Berlin -- Germany is home to around half of Opel's 50,000 workers -- by proposing to keep all four Opel plants in Germany open.

A spokesman for the German economy ministry told reporters that Berlin was not aware of any problems that might stop the sale of Opel to Magna.

There are no new problems, the spokesman said.

GM's 13-member board agreed to sell Opel in September, but European Union regulators have asked GM to confirm it would make the same decision knowing that 4.5 billion euros in state aid promised by Germany would go to any buyer of Opel.

(Additional reporting by Hans-Edzard Busemann in Berlin; writing by Helen Massy-Beresford; editing by Karen Foster)