FRANKFURT, March 23 German services trade union Verdi said it would extend strike calls in support of higher public sector pay to staff at Frankfurt airport next Thursday, adding to a list of actions likely to hamper German air traffic.
"It is safe to assume that there will be considerable delays that day," the union said in a statement.
German trade unions have staged strikes in public transport and services this month after a first round of public sector pay talks failed to produce any signs of a deal.
Verdi said that it would increase the pressure on public employers after the second round of talks left the two sides still far apart.
A spokesman for Frankfurt airport operator Fraport said that the company called on the union not let the dispute affect airline passengers.
A strike by private-sector security staff at Frankfurt airport last month caused dozens of flight cancellations and delayed thousands of passengers, bringing chaos to Europe's third largest hub.
In addition, German airline Lufthansa is facing more strikes after pilots voted on Friday to back their demands for better pay and working conditions with industrial action.
The pilots' union has not set a date yet for the strike but did not plan, for now, to call it over the Easter holidays.
Pilots last took strike action in 2010, causing the cancellation of hundreds of flights in a row over shifting contracts to different units within the Lufthansa group with lower pay. (Reporting by Ludwig Burger and Myria Mildenberger; editing by Keiron Henderson)