Magna International thinks it can clinch a contract to buy a majority stake in carmaker Opel from General Motors even as GM's board weighs its final word, Magna's co-chief executive said.

I am convinced that we will sign the contract soon if the EU...agrees. We are very, very hopeful, Siegfried Wolf told an industry conference on Wednesday.

GM's board of directors is due to meet on Tuesday to reconsider the deal, hammered out with the financial backing of the German government, after competition authorities in Brussels expressed concerns about the fairness of the bidding process.

The European Commission has been keeping a close eye on the transaction to ensure state aid is not misused for political purposes and was not skewed in favor of Magna.

Magna and its Russian partner Sberbank 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.

Financial investor RHJ International and carmakers Fiat and BAIC had also been in the running for Opel, although RHJ has since said it is no longer interested.

It remains unclear as well how Germany's new center-right government will view the deal, which returning Chancellor Angela Merkel helped broker.

The liberal Free Democrats, new partners of Merkel's conservatives, are broadly skeptical of the planned sale of Opel to Magna, but party member Rainer Bruederle, who is set to be sworn in as economy minister on Wednesday, has said there is no way the new government can stop it.

(Reporting by Boris Groendahl via Frankfurt newsroom)