Paris: Pilots at Air France have voted in favour of strike action over pay conditions, the head of the SNPL union said on Monday.
SNPL chief Philippe Evain said more than two thirds of the union's pilots with Air France approved the principle of a lengthy strike but said that no date had been set for the walkout.
The strike was in protest against the airline's "obsessive reduction of costs," Evain said. It comes after the pilots union rejected proposals from Air France in talks over productivity in April.
It was not immediately clear whether the timing of the walkout by pilots would coincide with the current wave of public transport protests and oil sector strikes against government plans for labour law reforms.
But the threat of France's flagship airline grounding flights will be a further headache for President Francois Hollande's Socialist government ahead of the June 10 start of the Euro 2016 soccer tournament.
Air France-KLM declined to comment.
Meanwhile, workers at the CIM oil terminal that handles about 40 per cent of French crude imports have voted to extend their strike at the Le Havre oil port hub until 1000 GMT on Wednesday, a CGT union official told Reuters.
"There will be another vote on Wednesday afternoon," the official said after Monday's vote.
Le Havre is France's second-biggest oil port and the action by workers, part of nationwide strikes against a planned labour reform, has disrupted the delivery of crude to refineries and refined products clients.
However, managers took over operations at the CIM terminal late last week and reopened pipes.
A source at the Le Havre port told Reuters that 17 managers and engineers have been operating the plant round the clock since last week after the government ordered pipes to be reopened to allow supplies to flow.
"They have been working non-stop since Tuesday, sleeping on site," the source told Reuters. "Sometimes, picketing union members have gone out to get some food items for them."
A spokeswoman for CIM declined to comment.
A CGT union member official told Reuters that there was a security risk with 17 people doing what would normally be done by a team of 38.
"Of course these are senior guys and engineers who know what button to push, but there is a risk with so few people," he said.
CIM, which supplies nearby Exxon Mobil's 240,000 barrel-per-day Port Jerome-Gravenchon refinery, is central to France's oil sector. The Port Jerome refinery is one of three refineries among the eight in France that has not been halted by the strike.
The hub at Le Havre port has 2.4 million cubic metres of crude storage capacity and 1.7 million cubic metres of refined products storage capacity for jet fuel, diesel, petrol and naphtha. It supplies jet fuel to the three airports in the French capital.