Wearing black rubbish bags marked with crosses, more than a thousand Alcatel-Lucent workers marched to the Eiffel Tower.

The telecoms firm's employees were protesting against plans to cut 10,000 jobs around the world to save €1 billion (£850 million).

But boss Michel Combes warned the workers the firm "could disappear," claiming "the company hasn't made money since 2006."

Mr Combes blamed bad decision-making since the 2006 merger of France's Alcatel and US-based Lucent Technologies, such as abandoning high-growth countries, lack of innovation and failure to make the leap to new technology.

He didn't, however, volunteer the decision-makers to be sacked instead of 10,000 workers.

"The plan sets targets that are key to the survival," he insisted. "But it can obviously be improved. That's the point of talks that begin today."

Mr Combes said he had four months to negotiate with unions.

The chief executive took over in April and faces resistance from the French government.

Prime Minister Jean-Marc Ayrault said new labour rules could be invoked to stop the company forcing cuts.

"If there is no majority agreement with unions, the restructuring plan won't be accepted because the law now gives the state the responsibility to act.

"We want a negotiation that saves as many jobs as possible, as many sites as possible," he said.

The plan would shut sites in Rennes and Toulouse and sell others.