Air France pilots have embarked on a four-day strike that could disrupt transport plans for football fans on the second day of the European Football Championships.
The pilots are protesting against pay cuts.
The airline said on Saturday it estimated that about 25 per cent of its pilots would strike.
It added that it was operating 83 per cent of flights – 93 per cent of the long-haul flights from Paris, 91 per cent of its domestic flights and 73 per cent of its medium-haul flights to and from Paris-Charles de Gaulle airport.
For Sunday, Air France said it expected that 27 per cent of the pilots would strike and expected to operate almost 80 per cent of its flights.
An Air France spokeswoman told Reuters it expected a similar trend for Monday.
The airline has said it would strive to ensure minimal disruption to flights serving cities hosting Euro 2016 football matches.