Frankfurt - Lufthansa, Germany's largest airline, said it had cancelled around 600 flights - about a third of its services - on Thursday due to a planned strike by public-sector workers across the country's airports.
Trade union Verdi has called on ground staff, baggage handlers and maintenance staff at almost all of Germany's big airports, including Europe's third largest hub at Frankfurt, to strike during the morning shift on Thursday, which runs until around 15:00 SA time.
The union's aim is to increase pressure on the government ahead of a third round of pay talks due to start at the end of the month.
The walkout is part of wider industrial action that has also seen strikes by a range of other public-sector workers, including local transport staff and childcare workers.
Lufthansa, which typically operates around 1,800 flights on a Thursday under its Lufthansa and Germanwings brands, said it was cancelling almost all of its domestic flights that were due to take off before 15:00 SA time.