Fiat boss Sergio Marchionne has told Opel a merger is its best option for the future and would mean platform sharing on all large cars will take place by 2012.
The planned sale of Opel has pitted Fiat against Magna International and both have submitted proposals to the German government.
Marchionne said in an interview, “I'm offering the German government a car business that will be effectively debt-free and I will take on Opel's liabilities, including pensions. I told them, 'If you have a better offer, take it.'”
Fiat believes that a deal will save Opel at least €1 billion (£890m) a year, although it has warned of cost-cutting measures at European factories.
This has led to concerns that Fiat would axe both of Opel/Vauxhall's British plants as part of a bid to cull 18,000 jobs.
The alliance between Fiat and Chrysler announced last week will undoubtedly lead to platform sharing, but Marchionne believes that a deal with Opel would provide faster results.
"We can achieve convergence on all the big platforms by 2012. Ultimately, I need to do this with Chrysler, but Opel gets me there much faster and with more immediate returns," he said.