Pilots at Deutsche Lufthansa AG's CityLine subsidiary launched a 36-hour strike on Thursday over pay that is expected to lead to more than 300 short-haul flight cancelations.
The Cockpit union announced the walkout late Wednesday evening, which began at midnight (2200GMT). It is expected to last until noon on Friday (1000GMT).
Lufthansa said the strike was expected to lead to 360 flight cancelations on Thursday out of a total 400 scheduled flights by CityLine, which operates only on domestic and European routes.
The airline had to cancel about 1,000 domestic and European flights last month due to a previous strike by Cockpit at CityLine and another subsidiary, Eurowings.
Separately, ground staff staged a five-day strike last week. That was resolved when Lufthansa and the ver.di service workers' union reached a pay deal on Friday, but the airline is still working to clear a maintenance backlog and get all its planes back in service.