Eurowings has cancelled around 170 flights scheduled over New Year due to strike action by cabin crew belonging to sister company Germanwings.
The Lufthansa-owned low-cost carrier published an announcement on its website on Sunday detailing the impact to its services.
Germanwings employees began industrial action at midnight on 30 December and will return to work from midnight on Wednesday, 1 January 2020.
The UFO union wants to secure members higher pay and better benefits, as well as making it easier for staff to get long-term contracts.
Talks over the weekend broke down, with the union rejecting management concessions.
Most of the impacted flights are domestic services within Germany, but some flights to Austria and Switzerland have also been axed.
Schedules at Cologne-Bonn, Munich, Hamburg and Berlin-Tegel airports are the worst hit.
"Eurowings wants to keep the impact of the strike on its passengers as minimal as possible and is working on a special flight schedule for the strike period," the airline said in a statement.
Around thirty of its 140 operational aircraft are used by Germanwings, Eurowings added.