Germany's largest airport, Frankfurt, is bracing for travel delays due to a scheduled wage strike by security personnel.
"Due to strike action planned by security staff for Friday, February 21, flight disruptions and cancellations are likely to occur at Frankfurt Airport," the airport's operator Fraport said on its website.
"Passengers are advised to check their airline's website and the traffic reports before travelling to the airport and allow extra time for their journey."
Service industry union Verdi called on members employed by private security contractors to stay away from work between 2am and 11pm on Friday.
Fraport and Germany's biggest airline Lufthansa said they could not estimate the extent of delays and flight cancellations.
Verdi is fighting for an hourly wage rise to 16 euros ($A25), calling an offer by employers of 10-13 euros "far too low".
