French union activists have disrupted Marseille airport and halted activity at half of the country's oil refineries in protests over changes to the labour system.
But nationwide fuel shortages have eased slightly after government intervention.
Tensions let up slightly after one-day strikes and protests on Thursday pitting unions against the socialist government and leaving many drivers short of fuel.
The heart of their dispute is a labour bill that would loosen rules on France's 35-hour work week and make it easier for employers to hire - and fire.
Some unions continued the strike into Friday, and France's main oil company Total said four of its eight refineries were at a standstill.
French media reported that the oil terminal in Le Havre on the English Channel also remained shut by strikes.
But pressure on petrol stations eased, with fewer lines visible at stations in the Paris region.
Earlier in the week, 30% of stations were out of fuel or running low, notably amid panic buying, but Total and the UFIP national oil industry lobby reported improvements on Friday.
The CGT union, which has been leading the protests, instead focused its attention on a trial of Air France union members accused of tearing the shirts off airline executives in a violent protest last year.
The judge in the trial in Bobigny outside Paris postponed the proceedings until September, amid fears that it could enflame tensions.
"It's the beginning of a revolution. This is about the future of our country," defendant Sri Colbert said.
Union activists rallied outside the courthouse. Across the country, others briefly blocked entrances to the Marseille airport in solidarity with the Air France workers on trial, according to Marseille CGT member Maxime Picard.
The shirt-ripping incident last October, caught on camera and viewed worldwide, came to epitomise antagonism in French labour relations.
It occurred after a meeting where the executives announced further job cuts after years of belt-tightening at the airline.
Air France lawyers condemned the delay of the trial, arguing that the exceptional violence should be punished as soon as possible, and not be linked to the larger protest movement.