German Gref, Sberbank chief executive and a former Russian trade minister, said the bank would go to court unless GM agrees to cover the expenses incurred by the Russian state-owned bank in talks to buy GM's European unit Opel.
"We have formulated all the expenses now and forwarded to the company a proposal on voluntary compensation of the costs," Ria-Novosti news agency quoted Gref as saying.
"If it is not accepted, then we will seek the compensation through legal proceedings. We have sustained serious losses," Gref added without elaborating.
Sberbank chief executive said last month his bank was weighing legal action against GM. Russia felt cheated after GM in November scrapped plans to sell a 55-percent stake in Opel to Canadian auto parts maker Magna and Sberbank, despite a preliminary deal reached after months of talks.
"Nine months of talks, 9,000 initialed pages of the contract had been ready for signing," Gref said according to Interfax. "And two days before the deal GM abandoned it."
Russian officials had hoped the deal would be a chance to boost the country's ailing car industry and obtain top European automotive technologies and expertise.