PARIS: France faced the threat of fuel shortages on Thursday, a day after a wave of strikes against President Nicolas Sarkozy's pension reform plans shut down 70 per cent of its oil refining capacity.

The closure of the refineries carries the threat of further disruption if fuel stocks in depots and filling stations run low in coming weeks.

But Sarkozy remained determined to resist pressure to back down over his plan to raise the retirement age from 60 to 62.

He told a meeting of right-wing lawmakers he would "go no further" in terms of concessions, according to allies present at the lunch.

"Until the end of my mandate, I will put new ideas and reforms on the table," he said, promising to stay the course in the run-up to his expected 2012 re-election bid.

On Wednesday, a day after a massive nationwide protest brought more than a million workers and students into the streets, dozens of follow-on strikes erupted around the country, disrupting transport, schooling and services.

In some sectors, the total number of strikers had declined since Tuesday.

But eight of France's 12 refineries were in the course of shutting down operations -- a process that can take 48 hours to complete -- and another three saw their output severely disrupted by strike action.

"We are hardening our stance," warned Charles Foulard, head of the CGT union's branch at the French oil giant Total, confirming that members had voted for an open-ended strike.

A Total spokesman confirmed the shutdowns, but the chairman of the oil industry association said France's network of fuel depots had enough stocks to keep its 12,500 filling stations running for the moment.

However, Jean-Louis Schilansky warned that "If the situation continues as it is now, we'll have to take a serious look at the problem of strategic stocks."

There were scattered reports of panic buying causing tail-backs at filling stations and local shortages, and -- as more fuel will have to be imported rather than refined in France -- price rises were expected.

One Total refinery near Nantes in the west voted to continue its strike until Monday. Another near Rouen in the north, run by Petroplus, rolled over its strike into Thursday.

As the petrochemical industry complained it was losing hundreds of millions of dollars due to the refinery strike, unions pledged more protests on Saturday. Bernard Thibault, leader of the CGT, said they were "looking for new ways to pressure the government."

Tuesday's day of action saw students and school pupils join the rallies for the first time, swelling the marchers' numbers to between 1.2 and 3.5 million across the country, according to rival police and labour estimates.

On Wednesday only, one high-speed intercity link in three was operating and only four in 10 regional expresses, according to the SNCF national train firm.

International rail services such as the Eurostar to London and the Thalys to Belgium and the Netherlands were unaffected, and flights from Paris's main airports returned to normal after Tuesday's disruption.

Sarkozy's supporters have stepped up moves to push the pensions reform bill through parliament, gambling that protests will subside once it is passed.

But the vote on the bill in the French senate, which had been expected on Friday or Saturday, has been pushed back until October 20 to allow more time for debate, a lawmaker told AFP.

The right-wing president insists that with people living longer and France's public deficit at record levels, the French will have to work longer in order to help stem the shortfall in the social security account.

Unions and the Socialist opposition object that Sarkozy is making workers pay an unfair share of the bill for the financial crisis and have vowed to resist any attempt to abandon the cherished age-60 retirement age.

Channel NewsAsia - France fuel supply threatened by pensions standoff -