PARIS (Reuters) – Nationwide strikes paralysed France's oil refining industry yesterday, with only one out of 12 plants operating normally and some petrol stations reporting brief shortages due to panic buying.

A strike at Fos Lavera entered its 18th day yesterday — the longest on record at the key Mediterranean oil port — while workers at most refineries were also on strike as part of stoppages across the country that began on Tuesday over government pension reforms.

Unions yesterday called for a fresh day of strikes and protests on October 19 as the pension bill neared adoption.

Oil lobby UFIP increased pressure on the authorities to intervene, calling yesterday for strategic stocks to be used.

The government agreed to make some commercial stocks available for road haulage but said it was not tapping strategic reserves and called on motorists to avoid panic buying after demand at the pumps surged by 50 percent in the past two days.

Striking workers were blocking fuel supplies at nine of the country's 12 oil refineries, union officials said. Workers would also block an incoming tanker at the LNG gas terminal at Montoir port on the Atlantic and gas supplies to the national grid would stop tomorrow, they said. Strike action at refineries and also at the Fos-Lavera oil port meant seven refineries were in the process of shutting down, they said.

"The situation is hardening, people are no longer even asking themselves whether to continue the movement," a union official at Total's Grandpuits refinery told Reuters.

Benchmark European gasoline prices rose to fresh five-and-a-half month highs, just shy of testing the $780 mark due to the prolonged strikes in France and maintenance work at Royal Dutch Shell's Pernis site, Europe's largest refinery, in Rotterdam, traders said.