Lufthansa pilots are planning to extend their strike action to Friday potentially causing disruption to thousands of passengers.
Pilots from the Vereinigung Cockpit union have been on strike for the past two days affecting short and long-haul flights.
The pilots' union is hoping strikes will put pressure on management during negotiations on retirement benefits.
A Lufthansa spokesperson told The BBC that the airline would be able to fly three-quarters of flights on Friday across all carriers under the Lufthansa group, including Swiss International and Austrian Airlines, but added it would like to resume negotiations with the union.
“With the third strike notice in three days, the pilots are escalating the labour dispute on the backs of our passengers instead of constructively finding solutions at the negotiating table,” Lufthansa said in a statement.
The airline said it would do everything in its power to keep the impact of the strike as minimal as possible.
The strike is the latest in a series of walkouts called by the union, which is protesting plans to change the current scheme that sees pilots retire at 55 and retain some of their pay until they reach the state pension age.
Lufthansa said it has made concessions in recent talks, including giving the pilots a 5 per cent pay rise.
Lufthansa said it had to cancel 750 flights due to the strike on short and mid-haul flights at Lufthansa’s passenger airline on Wednesday. For Thursday’s strike, the airline said it cancelled 42 long-haul flights
It's not about preventing strategic business decisions," said Jorg Handwerg, a spokesman for the union said in a statement on its website. "Competition should not lead to a sell-off of the values that have a significant role in ensuring that Lufthansa has become one of the world's leading aerospace companies."
The frequent strikes by Lufthansa — and Air France — pilots are the result of the long-established carriers clashing with unions as they try to cut costs to compete with budget airlines.
Earlier this month, Lufthansa said it lost €232 million last year due to ten such strikes.