Article published on the 2009-07-22 Latest update 2009-07-22 10:21 TU
Workers at the plant in Montceau-les-Mines in the central region of Saone-et-Loire were protesting against the treatment of an employee on a short-term contract.
"Four members of the management, including the director of our Monceau factory, are being held by a group of about 50 workers," a spokesperson for the group told the AFP agency late Tuesday.
The dispute centred on the sacking of a man who had been asked to work on machines that he was not trained to operate.
The managers were released early on Thursday.
It is the latest in a series of such incidents in France and came on the same day as workers held two managers of US cigarette paper manufacturer Schweitzer-Mauduit for more than three hours in Malaucène, south-eastern France, demanding they continue to negotiate over the closure of their plant.
In all cases so far, managers have been released unharmed.
In the last week, however, there have been two incidents of workers threatening to blow up factories unless management met their demands.
France - industrial unrest