The move was the latest in a long line of so-called “boss-napping” incidents in which executives are prevented from going home by French trade union activists as part of strong-arm negotiating tactics.
The latest clash occurred at the Fonderie de Bretagne, a foundry near the town of Lorient that has been put up sale by Renault.
The car maker “strongly condemned” the detention of seven local managers on Tuesday morning, calling for them to be allowed to leave.
The managers were released at around 10.30 pm, union rep Mael Le Goff from the hard-left CGT union told AFP on Tuesday.
“They still didn’t want to have a dialogue so it was pointless trying to talk to people who don’t want to engage,” Le Goff said.
Renault said it was trying to find a buyer for the factory, which employs 350 people, in order to “maintain activity at the site and safeguard jobs.”
While managers at the Renault foundry have been freed, it remains closed and picketed by workers who are demanding that the global car giant put an end to its plans to sell the site.
“We are still waiting for progress with this issue,” union rep Le Goff said. “It’s been going on for a year, it’s exhausting.”