European Union anti-trust authorities will examine if Germany's 1.5 billion-euro (£1.3 billion) bridge loan to Opel meets regulations.
The loan has been extended to keep Opel and Vauxhall running while the sale to Magna is finalised. However, there have been concerns that the loan breaches EU competition rules.
"The European Commission will verify that the loan was fully inline with the scheme that we have already approved," Commission spokesman Jonathan Todd said. "We will do it as quickly as possible but it will be dependent on the extent of the information we receive."
Todd confirmed, however, that the EU Commission does not need to approve the loan before it can be given, as the German government previously received EU permission for a scheme to allow it to grant aid in the form of guarantees for investment and working capital loans until the end of 2010 earlier this year.
The only caveat was that only companies that were in difficulty after 1 July, 2008, could benefit from the plan.