Five European countries are now backing a plan that could see Opel dealers take a minority stake in the automaker.

Dutch dealers have agreed to invest in any fund to keep the troubled carmaker in business, joining a plan pioneered by German outlets to take a significant equity stake in the carmaker, provided Opel employees helped fund the purchase and the state kicked in financial support, according to Reuters.

Dutch dealers' association VODN chairman Erik Selles said 96% of members voted in favour of the plan, which asks dealers to deposit EUR150 of proceeds from each car sold in a fund for three years.

"It is a lot of money, but it is important to get a substantial stake in the new Opel situation," Selles told the news agency.

European Opel dealership association Euroda, which expects to put the plan to a final vote on 15 May, said last month EUR400m could be generated if all countries and dealers participated but it also warned the money would not be immediately available, the report noted.

"So far, the plan has been approved by Germany, Austria, Norway, Romania and the Netherlands," Euroda chairman Jaap Timmer said, adding that Euroda spans 25 countries and it is only in the middle of the approval process.

"This initiative is unique in this branch," Selles said in a statement. "Dealers and their clients will get more influence on the decisions of Opel, and that has never been displayed before."

Euroda hopes discussions at a national level will be finalised in April ahead of its planned May vote.