Lufthansa said its flights will be getting back to normal today following three days of strike action.
In preparation for the industrial action, it cancelled 3,800 flights, affecting 425,000 passengers and hitting earnings by a "medium double-digit million figure".
It said around 20,000 20,000 customers were able to take the train instead, and Lufthansa switched others to the remaining members of the airline group, Star Alliance airlines or external carriers.
More than 25,000 tickets were rebooked on www.LH.com.
It said although the capacity of the call centres was extended as much as possible, it was not possible to avoid long waiting times.
On normal days, the Lufthansa call centres receive between 4,000 and 5,000 calls from customers, but on Tuesday this jumped to 80,000 and on Wednesday the figure was 25,000.
“We have prepared for this in the best possible way and significantly increased capacities at our call centres in advance, so as to assist our customers with rebooking flights," said Jens Bischof, chief commercial officer.
"Unfortunately, with such extremely high call volumes, in some cases, long waiting times cannot be avoided. We would like to apologise to our customers for this."
It said flight operations at both Lufthansa and Germanwings should be back to schedule on Saturday, but warned there may still be some irregularities due to operational reasons.
"This very swift return to normal operations is possible because, for the duration of the strike, the aircraft and crews have been stationed where operations are to resume upon conclusion of the strike," it added.
