Lufthansa may seek compensation after dozens of flights at Frankfurt Airport had to be canceled amid heightened security because of US President George W. Bush's visit to Germany on Wednesday.
Lufthansa and its partners, including its regional airlines, scrapped 77 European flights, affecting some 5,000 passengers.
Also, 178 flights were delayed by about an hour on average, a spokesman for the carrier said. Lufthansa and its partners normally operate about 750 flights on a Wednesday in total.
Lufthansa said it was examining whether it would seek damages from German state-owned air traffic controllers Deutsche Flugsicherung (DFS) following the disruption. The carrier said it could not yet say how much money it may seek.
Bush landed at Frankfurt at about 0845 GMT on his way to talks with German Chancellor Gerhard Schroeder on the second leg of a three-nation tour of Europe designed to patch up differences over the Iraq war.
Frankfurt airport operator Fraport said more than 100 flights had been scrapped at continental Europe's biggest passenger and air cargo hub.
"The problems are worse than feared," a Lufthansa spokesman said, adding that DFS told the airline only on Tuesday evening that it was increasing security precautions for the visit.
DFS said it changed the security arrangements again at the request of the transport ministry.
Spokesmen for DFS and Fraport said earlier that bad weather had caused a large part of the disruptions. The Lufthansa spokesman disputed this.
