Norwegian is seeking to convert debt to equity, money from shareholders and Norwegian state guarantees in a bid to survive the coronavirus crisis.
It said the four companies are staffing units and the cancelled agreements involve firms providing crews based in Spain, Britain, Finland, Sweden and the United States.
Combined, it said some 4,700 pilots and cabin crew members would be affected while about 700 pilots and 1,300 cabin crew based in Norway, France and Italy remained unaffected.
"We have done everything we can to avoid making this last-resort decision and we have asked for access to government support in both Sweden and Denmark," CEO Jacob Schram said in a statement.
"Despite the measures that the company has already taken, coupled with the lack of significant financial support from the Swedish and Danish governments, we are left with no choice," the company said.
"We are working around the clock to get through this crisis and to return as a stronger Norwegian with the goal of bringing as many colleagues back in the air as possible," Schram said.
© Reuters, aero.uk | Image: Norwegian Air | 20/04/2020 14:39