Frankfurt - German pilots at Lufthansa's low-cost unit Germanwings are to go on strike on Thursday, forcing the cancellation of 100 flights - or around a fifth of its services - as a dispute over an early retirement scheme drags on.
The strike, the seventh at Lufthansa this year, will last for 12 hours - from 10:00 GMT until 21:59 GMT on Thursday - and affect flights across the country, the Vereinigung Cockpit (VC) trade union said in a statement on Wednesday.
Strikes by pilots are hampering both Lufthansa and rival Air France-KLM in their efforts to expand low-cost operations that will allow them to compete more effectively with budget carriers such as Ryanair and easyJet on short-haul European routes.
The Germanwings strike comes after a 14-hour strike by German train drivers created travel disruption for travellers across the nation on Wednesday.
VC, representing about 5 400 Lufthansa pilots, wants the airline to maintain a scheme that allows pilots to retire early at the age of 55 and still receive up to 60% of their pay before regular pension payments start.
Management, under pressure to reduce costs to better compete with the budget rivals and also fast-growing airlines from the Middle East, has offered to keep the pension scheme for employees who started before this year but wants to increase the earliest possible retirement age for new recruits.
The union, however, has rejected this and has offered to help cover the costs of the scheme.
"Unfortunately, Lufthansa has not taken on VC's proposals for compromise and is continuing to stonewall," the union said, adding the airline's customers should be prepared for further strikes ahead.
A six-hour strike at Germanwings in August cost Lufthansa more than €10m ($12.7m).
Germanwings operates short-haul flights in Europe. The unit, which would normally operate around 500 flights on Thursday, said the cancelled flights were mostly domestic ones. Passengers on domestic flights are likely to be switched to trains, as Lufthansa has done with previous strikes.
"The escalation shows that it's not about a constructive solution for VC but rather about causing the most possible damage," a spokesman for Germanwings said.
Air France pilots staged a two-week strike last month which the French carrier said cost up to €500m, enough to wipe more than a fifth off its estimated full-year core profit and sending its shares to a 13-month low.