German airports have been severely disrupted after members of the Verdi public sector union went on strike.
Passengers at Frankfurt airport face delays due to the Verdi strike
Frankfurt airport cancelled about 80 flights and said services would not be back to normal until Thursday.
The strike has also grounded 142 Lufthansa flights, mainly on domestic routes, with Stuttgart, Munich, Cologne and other airports hit.
Verdi is pushing for an 8% wage increase for its two million federal and local government workers.
The union has rejected the government's proposal of a 5% wage rise over two years, which would also involve longer hours. Both sides are due to hold more talks on Thursday.
The planned strikes for Wednesday come after Verdi union members working on buses, trains, waterworks and schools took part in walk-outs on Tuesday.
Lufthansa said it would cancel domestic and European-bound flights, but that long-haul international flights would not be affected.
In Berlin, a separate strike by transport workers has hit subway, tram and bus services.
Train drivers' union GDL has also threatened strikes starting next Monday on both passenger and freight trains, intensifying an existing argument with Deutsche Bahn.
A strike by GDL over 62 hours in November last year caused considerable disruption, with economists estimating that it cost 75m euros a day.