Renault moved closer to securing the agreement of workers to a wage freeze needed to avoid factory closures and forced job cuts in France after a top union endorsed the deal on Friday.
The approval from the CFE-CGC union that represents nearly 30 percent of workers means that Renault only needs one other union to sign onto the deal.
Another union, the CFDT, has spoken positively of the agreement but will not take a decision until next month.
Renault announced plans last month to cut 7,500 jobs in France through natural attrition and early retirement, but pledged not to close any factories if unions agree to changes that would allow the company to compete more effectively worldwide.
Among the measures Renault is pushing for are a wage freeze this year and a harmonisation of working hours.
Renault earned a net profit of 1.77 billion euros ($2.3 billion) in 2012, but is seeking to scale back its production after new car sales in France plunged 14 percent last year.