French carmaker Renault has won support from workers for a nationwide deal on pay and conditions to boost its competitiveness as a second union gave its backing to the move on Wednesday.
Force Ouvriere said in a statement that it had decided by a large majority to sign the new agreement "for a new growth dynamic and social development at Renault in France".
The decision follows a similar move by Renault's main union, the CFE-CGC, last month, giving Renault enough support to validate the accord.
A Renault spokesman had no immediate comment, however.
A deal between the company and unions is expected to be officially signed following a works council meeting next week.
Shares in Renault extended their gains, up 2.4 percent at 51.15 euros by 7.10 a.m. ET. The stock is up 25 percent since the start of the year.
Renault has been pushing workers to accept a deal to enable it to cut costs and align productivity with cheaper European sites such as its Palencia plant in Spain and alliance partner Nissan's <7201.T> Sunderland factory in England.
Automakers across Europe are cutting costs and capacity so they can still turn a profit while the euro zone debt crisis and resulting government austerity measures sap consumer demand.
French car registrations fell for the 15th consecutive month in February, down 12 percent, as a weak economy continued to weigh on demand for new vehicles, according to the CCFA auto industry body.
French Industry Minister Arnaud Montebourg issued a statement to say he planned to hold a press conference on the automobile industry at 6.00 a.m. ET on Thursday.
(Reporting by James Regan; Additional reporting by Gilles Guillaume; Editing by Christian Plumb)