Union officials say some 2,000 pilots have gone on strike in Sweden, stalling almost all domestic flights and affecting around 23,000 passengers.
Members of The Swedish Air Transport Industry Employers' Association are protesting four airlines' plans to employ pilots on a freelance basis. They claim it bypasses employment regulations in collective bargaining agreements.
Some 500 flights were canceled due to Wednesday's strike, mainly affecting domestic routes but also some international flights. Union spokesman Dag Gustavsson says pilots at the four airlines directly involved - Avia Express, Golden Air, Avitrans Nordic and Svenskt Direktflyg - will strike until 2100 GMT, while other pilots who are striking in sympathy will end their action at 1100 GMT.