US tyre firm Goodyear signed Wednesday a pact with a French union that significantly improves severance benefits for workers at a plant in the country's north threatened with closure. The deal comes after seven years of sparring between the unions and the management, which announced a year ago that it would shut down the plant in Amiens employing 1,173 people. In a last-ditch bid to save the plant and get better severance packages, workers -- led by the CGT union -- "bossnapped" the factory's head of production Michel Dheilly and human resources director Bernard Glesser by locking them up. Goodyear had refused to negotiate until the executives -- who were treated well throughout their 24-hour detention -- were freed. The new deal "provides payoffs that are three times higher for all workers," the CGT said in a statement but did not give any figures. Goodyear said it provided "significantly higher compensation" and described the package as one "that favours all the workers." France's Industrial Renewal Minister Arnaud Montebourg said the deal could "pave the way" for US firm Titan, which has offered to take over part of the plant, to step in. Titan's tough-talking chief Maurice Taylor made waves last year when he wrote a letter to Montebourg calling French workers lazy and overpaid after years of negotiations by Titan to take over the plant had failed.