Air traffic in France is being strongly affected Thursday by a strike in several European countries by dissatisfied Air Traffic controllers, with two out of three flights to be either delayed or cancelled, according to one airport source in Paris. Air traffic controllers in France, Italy and Portugal have all announced they will walk off the job on Thursday to protest restructuring order by the European Union in the air traffic arena. Strikes are also scheduled in Austria, Hungary, Slovakia, Czech Republic, Greece and Cyprus. The French Airport Authority (DGAC) has already called on companies to cancel 20 percent of their flights after strike action began at midnight and is due to last for 24 hours. The cuts in traffic will mostly affect Paris Charles de Gaulle and Orly Airports, as well as flights to low-cost airport, Beauvais, the authority said. Passengers travelling Thursday to or from France have been advised to contact their carriers for more information.