General Motors is “reasonably confident” that a deal to sell Opel to Magna International and Sberbank will be signed this week despite a warning by the European Union that the proposed sale might breach state aid rules, Fritz Henderson, GM’s chief executive, said in an interview on Monday.

“The German government is in dialogue with the EU, and that’s kind of in their job responsibility code, if you will,” said Mr Henderson. GM, meanwhile, is now working to finish the remaining items in its negotiations with Magna and to work with the German government on terms of the deal’s financing.