A French air traffic controllers' strike forced cancellation of some flights in and out of Orly, Paris's second airport, on Monday at the start of a week of threatened air travel disruption in the French capital, Reuters reported. France's civil aviation authority (DGAC) said one in two flights was cancelled at Orly, south of Paris. There had also been some delays to flights at the larger Charles de Gaulle airport at Roissy, north of the capital, which is home to Air France, a DGAC spokeswoman said. Both airports are owned and operated by Aeroports de Paris ADP.PA. The CGT union was protesting at plans to move Orly controllers to Roissy before regrouping them all on one site near Paris in 2015. The CGT last week foresaw industrial action continuing up to next Friday with up to 50 percent of flights being cancelled at Orly and lesser disruptions at Roissy. The more moderate CFDT union withdrew plans for similar action after talks with the DGAC "I had a flight this morning for Bordeaux which was cancelled so I now have a flight at mid-day. So I'll be spending my morning here, waiting," said passenger Nicole Geantet at Orly. "The air control authorities are trying to change the way air traffic control works but no-one believes in it. The biggest ever European study invalidates it," said Jean-Paul Armango, a member of CGT's air traffic branch. The strike is the latest in a series of industrial actions to hit Paris air traffic.