A framework for an agreement on the layoff plan was agreed to and Luc Rousselet, 3M's director of French operations, was allowed to leave the factory.
The company recently announced layoffs at 3M facilities worldwide, including nearly half the 235 workers in this plant in the town of Pithiviers, just south of Paris.
"Negotiations are going to resume and it's a very good thing. … I'm satisfied and the conditions I was in were not that hard," Rousselet told reporters outside the plant after he was released. "I know it's a difficult plan for the people, so I understand the distress people may have."
Boos from around 20 workers could be heard as Rousselet left the office.
Earlier, French TV showed Rousselet locked up alone in an office, in front of his computer, talking on the phone and eating.
He told France 2 TV through the half-open door of the office that "it's going very well." A group of employees could be seen in front of the office, playing cards, reading newspapers and talking.
Rousselet said he slept for a few hours on a flattened cardboard box after the negotiations broke off at 3 a.m. Wednesday. Groups of 20 employees took turns watching him.
Across France workers have protested the growing layoffs and economic instability brought on by the worldwide recession. They burned tires and marched on the presidential palace today in Paris.
Earlier this month, employees at a Sony videotape factory in southwest France detained the head of Sony France and three other executives overnight and eventually secured improved terms for workers facing layoffs.
Aggressive worker protests are part of the culture, observers say.
"When workers have a grievance in revolutionary France, the laws of the republic are suspended," Ted Stanger, a U.S. journalist living in Paris who has written numerous books on the French, told ABCNews.com. "They can kidnap, they can virtually do what they want and the police will not intervene, because it's considered that workers have all the rights. So, that explains why they can presume to hold somebody hostage when in any other part of the world it's considered a terrorist act."
At 3M, Rousselet said the employees took him hostage after he rejected what he described as a last-minute demand from the unions -- payment for days employees were out on strike.
"This is something they put on the table at the last minute," Rousselet told France Info radio Wednesday morning. "One has to assume his responsibilities. It's also unfair for people who did not go on strike. My personal case is not dramatic, to spend a night in an office. I think people who are affected by this restructuring plan are certainly to be more pitied."
ABCNews.com could not reach Rousselet for further comment and 3M France officials declined to reply.
The Minnesota-based company has been warning of changes since late last year.
"This production site, which manufactures spray cans, tablets and transdermal patches ... has faced confrontation for several months over surplus production given the continual decline in customer demand," 3M said in a news release in December.
"Attempts to try to find a partner did not succeed, thus the decision to stop the manufacturing of medicines by the end of September 2009 was taken," the news release stated.