PARIS (AP) -- French workers on Wednesday released four managers they had held captive overnight at a British-run factory following a labor dispute over the plant's closure, officials said.
The managers at the plant in the foothills of the French Alps, run by Britain's Scapa Group PLC, were allowed to leave the site to attend negotiations Wednesday at the local mayor's office.
Ian Bushell, Scapa's European finance director, said the workers had promised they would not sequester the managers again when they return to the work site.
Hostage-taking has become a popular negotiating tactic among frustrated French workers in recent weeks.
In the past month, employees at French plants belonging to Sony, Caterpillar, 3M and German auto-parts maker Continental have held bosses in response to proposed job cuts and plant closures.
They have let them go within a day or two, often after winning some concessions. The tactic of holding managers has long been used in France, though sporadically, and has drawn new attention amid the economic downturn.
French President Nicolas Sarkozy denounced the tactic Tuesday.
"What is this story about going and holding people hostage?" he asked. "We are in a state of laws, there is a law that applies, I will ensure it is respected."
Employees of Scapa barred the senior managers from leaving Tuesday after negotiations over terms of the factory closure broke down. Workers blocked the entrance to the site with a truck, said Bushell, who described it as a "non-aggressive action."
The plant in Bellegarde makes adhesive tape for the auto industry, which is suffering its worst crisis in decades.
Employee representatives could not be reached for comment.
"Our primary concern is always for the safety of our people," Bushell said by telephone from the company's global headquarters in Ashton-under-Lyne, northwest England. "Our secondary concern is that we should immediately have a re-engagement of negotiations with the union."
The Scapa site in Bellegarde employs 68 people. Plans to close the plant were drafted in response to a faltering auto market, Bushell said. Tuesday's negotiations centered on job transfers or layoffs that would accompany the closing.
Discussions resumed Wednesday afternoon at the mayor's office, but Bushell said that the drastic actions of Scapa's French employees would "in no way whatsoever" alter the company's negotiating stance.
Steep labor costs have made France a target for several recent factory closings.
Bushell insisted that labor costs in France were not a reason for the Scapa closure. Scapa has plants throughout Europe and North America, as well as China and Malaysia.