Lufthansa cancelled at least 300 flights on Tuesday as cabin crew members staged another day of industrial action at three of the biggest airports in Germany.
Strike action called by the UFO union were in effect at Frankfurt, Munich and Berlin airports.
The BBC reports Lufthansa cancelled short and medium-haul flights.
Services to and from Los Angeles, Houston, Chicago, Beijing and Mexico City were also cancelled.
UFO and Lufthansa are in a dispute over pay and working conditions.
UFO chief Nicoley Baublies has threatened industrial action by union members across Germany if the airline does not compromise.
Lufthansa responded by saying that it was considering taking legal action against the union.
The BBC reports strikes could cost between 5-10 million euros (£3.9 million) per day.