AMSTERDAM (Reuters) - Cabin crews at Lufthansa <LHAG.DE> budget units Eurowings and Germanwings staged a strike on Thursday in a row over pay and conditions, forcing the carrier to cancel hundreds of flights.
The crew threatened more walkouts next week.
Thursday's strike at Duesseldorf, Cologne, Dortmund, Hanover, Stuttgart, Berlinand Hamburg airports is due to last for 24 hours until midnight (2200 GMT). The Lufthansa brand's main hubs of Frankfurt and Munich are not affected.
Lufthansa cabin crew and pilots have embarked on a series of strikes over the last few years as the airline battles to reduce costs in order to compete with low-cost rivals and long-haul carriers with leaner cost bases.
The current strike was called after new contracts talks collapsed between Eurowings, a regional carrier that Lufthansa is using as a basis to expand its budget offering, and cabin crew union UFO.
Increasing pressure on the group, the union also called a strike for staff at Germanwings, which is being merged with Eurowings. It cited a lack of agreement on part-time contracts, which Eurowings described as absurd.
Altogether Eurowings has canceled almost 400 flights, primarily short-haul flights in Germany and Europe, out of around 550 planned for Thursday.
At Duesseldorf airport, queues formed as passengers sought to rebook tickets. One passenger, Dick van der Aart, said he was irritated. "I got up very early and now I'm standing in a queue. Yes, I'm annoyed," he told Reuters.
Union UFO has been trying to agree new contracts for Eurowings staff in Germany for two years and has been threatening industrial action for weeks. The union on Thursday threatened further strikes for next week.
"If the employer's behavior doesn't change, we will strike on two days next week," UFO representative Daniel Flohr told Reuters, without saying on which days or at which carriers the walkouts could take place.
Eurowings, which put forward a new offer last week that includes an average pay increase of around 7 percent, said in response that the airline was prepared to resume talks at any time.
(Reporting by Victoria Bryan, Peter Maushagen and Reuters TV; Additional reporting by Matthias Inverardi; Editing by Georgina Prodhan)