Airlines have been instructed to scrap about 40 percent of the 4,000 services that would begin or end in France during a normal day in order to cope with the disruption, according to the DGAC civil aviation authority.

The French unit of Air France-KLM Group will halt two- thirds of flights at its Paris Orly short-haul hub, allowing the company to maintain most of its lucrative long-haul operations. About 60 percent of Air France services from provincial cities will also depart as usual, spokesman Christophe Paumier said.

Other carriers serving France have also been impacted, including Air France's Dutch sister company KLM. In Germany, Deutsche Lufthansa AG canceled 24 services in and out of France today and 13 tomorrow, while among non-European companies, Qatar Airways scrapped a flight to Paris's main Charles de Gaulle hub.

Low-cost carriers, which run to tighter timetables, are generally worse hit than network operators. Ryanair Holdings Plc, Europe's leading discount specialist, scrapped more than 250 flights today with more likely to follow, according to its website, while EasyJet Plc has terminated 118 services.

The 4,000 flights that use French airspace each day but don't touch down should not be not affected, according to the DGAC, though Air Berlin advised on its website that services to Spain, Portugal and Morocco could be impacted.

The DGAC plans to release cancellation requirements for Thursday once it knows how many controllers are still working.

The walkouts involve members of the SNCTA union who are seeking concessions on issues including retirement age and changes that will come as Europe moves toward a so-called single sky unifying air traffic control throughout the region.