With no end in sight, train and metro transport was again severely disrupted in Paris and on regional lines, as railway workers stayed off the job to protest the government's plan to merge 42 existing pension schemes into a single, points-based system.

The overhaul would see workers in certain sectors – including the railways – lose early retirement benefits, while millions more face benefit cuts.

Talks between unions and the government last week failed to find common ground, and a new day of mass protest has been called for January 9 – two days after negotiations are set to resume.

With some 42 percent of train drivers on strike, the SNCF rail company said just over half of its high-speed TGV trains would be running Friday, 20 percent of suburban trains in the larger Paris region, four out of 10 regional trains and a quarter of inter-city connections.

In Paris, only two of 16 metro lines – the only driverless ones – were running as usual, four were closed, and ten provided a much reduced service.

The government says the pension overhaul is needed to create a fairer system.

But workers object to the inclusion of a so-called pivot age of 64 until which people would have to work to earn a full pension – two years beyond the official retirement age.

The labour action, which started on December 5, is taking a heavy toll on businesses, especially retailers, hotels and restaurants, during what should be one of the busiest periods of the year.

Industry associations have reported turnover declines of 30 to 60 percent from a year earlier, and the SNCF said Tuesday it had lost 400 million euros ($442 million) in potential earnings so far.

The strikers, too, are losing out, forfeiting their salary for days not worked.

The man leading the pension reform project, Laurent Pietraszewski, said Tuesday the government would be "willing to compromise" in the negotiations. But he insisted there will be no revisiting the plan to do away with special retirement regimes.

Some 200-300 people turned out Thursday for a rally in Paris in support of the striking railway workers.

The longest transport strike in France lasted for 28 days, also over Christmas, in 1986 and early 1987.