Russian car maker GAZ has said it would be interested in creating a joint venture with Magna and Opel.
Magna is viewed as the main opposition to Fiat for buying General Motors' European business, which is centered around Opel and includes Vauxhall.
Both companies have presented proposals for their plans for Opel to the German government, which is being asked by GM to provide financial guarantees for the company.
Reports suggest Magna would take a 20 per cent stake in Opel and Gaz a 30 per cent stake if their bid was successful. Gaz's bid would be underpinned by backing from Russian banks.