UPDATE 1-French Nortel workers secure talks after blow-up threat

(Updates with negotiations)

PARIS, July 15 (Reuters) - Workers at the French arm of telecommunications manufacturer Nortel NT.TO have forced management into talks over layoff terms by threatening to blow up their factory, local authorities said on Wednesday.

Workers had placed gas cylinders that turned out to be empty in front of the plant in the Yvelines area near Paris after provisional management cancelled a planned meeting on Monday.

A total of 480 jobs are set to be axed at the plant following bankruptcy proceedings.

"Unions have agreed to remove the gas cylinders placed around the site after their demand was met," the local prefect's chief of cabinet said.

In the second threat by French workers to blow up a factory in a week, Le Parisien newspaper said the workers had threatened to stage an explosion as early as Wednesday if their demands were not met.

No immediate comment was available from Toronto-based Nortel, once the largest North American telecommunications equipment manufacturer but which filed for bankruptcy protection in Canada and the United States in January.

The workers were bitter about the way the authorities handling the case in France were proceeding, the paper said.

Speaking on LCI television, Labour Minister Xavier Darcos pledged to find solutions for the workers.

"We are going to speak to each other, we will find solutions that do not require resorting to extreme violence," he said.

"I can't understand why one would want to solve this problem through taking the position of a desperado," he said.

Other politicians also criticised the workers' methods.

Henri Guaino, adviser to President Nicolas Sarkozy, said he understood the workers' desperation but their reaction was unacceptable in a civilised society.

The factory protest is the second of its kind in recent days.

Workers at collapsed French car parts maker New Fabris made similar threats on Sunday, demanding they receive payouts by July 31 from auto groups Renault SA (RENA.PA) and PSA Peugeot Citroen (PEUP.PA) to compensate for their lost jobs.

Such threats of violence could become a strategy of disgruntled workers, who have detained managers at factories across the country in recent months in a spate of so-called "bossnapping" incidents.

For a factbox on recent bossnapping cases, double click on: [ID:nLN538422] (Reporting by Thierry Leveque and Sophie Hardach; Editing by Richard Balmforth)