Frankfurt airport strike to continue on Tuesday FRANKFURT (Reuters) - Ground staff at Frankfurt airport have plans to extend their strike, with labor union GdF saying it is now calling on them to halt work for an additional 24 hours from 0400 GMT on Tuesday. The strike by some 200 workers at Europe's third-busiest airport, which grounded hundreds of flights last week, was set to continue for a third day on Monday. A spokesman for airport operator Fraport said 223 flights were being cancelled on Monday, and about 70 percent of scheduled flights will take place. Lufthansa, which accounts for more than half of flights at Frankfurt airport, said it expects to cancel about 200 incoming and outgoing flights on German and European routes on Monday, while all intercontinental flights would take place. The workers, who guide planes in and out of their parking positions, want higher pay, arguing their jobs have become more complex following the introduction of a fourth runway last October. Reporting by Maria Sheahan and Peter Maushagen; Editing by Greg Mahlich