Germany's biggest airline Lufthansa is facing more aviation chaos, cancelling more than 900 domestic and European flights as cabin crew said they would resume a strike in a battle over cost cuts.
The stoppage - part of rolling industrial action the union threatened to continue until Friday - was due to hit Frankfurt, Duesseldorf and Munich airports on Monday, the UFO flight attendants' union said on Sunday.
Lufthansa said it would cancel 929 of the day's 3000 scheduled flights to or from the three cities, affecting 113,000 passengers, but that about 70 percent of its normal services would operate.
The airline also said its executive board would Monday discuss the "consequences" of the strike, which it called "unprecedented in the history of Lufthansa", and issue a statement to employees and the public.
"Lufthansa has today reaffirmed that it is ready to resume talks," it said in a statement.
The carrier voiced regret about the strike, apologised to customers and said it would publish new flight plans on their website and inform passengers of the status of their bookings by email and SMS.
Frankfurt, Germany's main air hub and Duesseldorf were to be hit by work stoppages from 03:30am to 10pm (local time), and Munich from 03:30am to 11pm (local time), the union said on its website.
UFO last Thursday said industrial action had become "unavoidable" after airline management failed to come up with an improved offer in a dispute over pay and early retirement provisions.
Not affected by the strike are Lufthansa's subsidiaries Germanwings, Eurowings, Lufthansa CityLine, SWISS, Austrian Airlines, Air Dolomiti and Brussels Airlines.
The strike forced Lufthansa to cancel 520 flights, leaving 58,000 passengers grounded. The stoppage affected all domestic and European flights from Frankfurt and Duesseldorf.
UFO has said it plans to target different airports over the course of the week-long blitz of walkouts.
The union is demanding that a current system of early retirement provisions remain unchanged.
Lufthansa has argued that the system is too expensive in the face of competition from low-cost operators such as Ryanair and easyJet.