Lufthansa is set to cancel 3,800 flights this week owing to a pilot’s strike, leaving only some 500 flights from Lufthansa and Germanwings.
The carrier said 425,000 passengers would be affected.
The group said that pilots at its other airlines, including Swiss International Air Lines, Austrian Airlines, Eurowings, Lufthansa CityLine and Air Dolomiti, would not take part in the strike.
The strike over pay and working conditions is scheduled for Wednesday, Thursday and Friday.
Lufthansa said it would inform passengers by text message or email about the flight changes.
Its freight carrier, Lufthansa Cargo, will also be affected.
Lufthansa said profits would be hit "in the range of tens of millions of euros" in what it called one of the biggest walkouts in its history.
"The announcement alone has already caused significant damages since passengers have already rebooked flights and logistic customers have made arrangements with other cargo airlines to secure the transport of their goods," it said in a statement.
