Air France will reduce flights by about 50% from tomorrow as pilots begin a one-week strike over company plans to cut costs to recapture market share from budget airlines, its chief executive said on Friday.

Speaking to France Inter radio, Francois Gagey said the strike, which could run until September 22, would cost the airline between 10-15 million euros a day.

Europe's second-largest traditional carrier by revenue said in early September it would open new bases in Europe under the Transavia brand to recapture market share from low-cost carriers and Middle East rivals.