Chief Executive Henri Poupart-Lafarge told workers' representatives that the closure plan was suspended until the plans had been disclosed, a CFE-CGC union official said. The government is due to present its proposals on Sept. 30.
The Socialist-led government is in talks with Alstom to prevent the company transferring manufacturing from the plant, which made France's first high-speed trains as well as the company's first steam engine in 1880.
Alstom, which is 20 percent state-owned, unleashed a political storm seven months ahead of a presidential election when it announced plans to stop producing trains at Belfort and transfer more than 400 workers to other sites.