Strike leads to 151 cancelled flights at Frankfurt FRANKFURT, Germany (AP) - Ground workers went on strike Thursday at Frankfurt airport, Europe's third busiest, leading to the cancellation of more than 150 flights. The strike was to last from 3 p.m. EST) until 10 p.m. Workers were expected to strike Friday as well. The GdF union is engaged in a dispute with airport operator Fraport over pay and working conditions for some 200 ground workers. Lufthansa airline said it had cancelled 100 flights within Europe because of Thursday's strike and would have to cancel more if the strike goes on for a second day. Transatlantic flights were not interrupted. Fraport says it's trying to retain at least half its 1,300 daily takoffs and landings during the strike. The airline said passengers on the cancelled flights could take a refund, rebook, or for some flights exchange their air ticket for a rail voucher. With 1,300 daily takeoffs and landings Frankfurt Airport is a key European hub behind London's Heathrow and Paris' Charles de Gaulle. Peter Schmitz, Fraport's executive in charge of operations, said a total of 151 flights had been canceled by mid-afternoon. In many cases, cancellations were announced well up front and passengers were able to rebook. "We have plans ready for tomorrow," Schmitz said. We have enough staff to be able, like today, to operate at least more than 50 percent of flights. Schmitz said management has had "no contact with the union" so far. GdF and Fraport have been unable to come to a new agreement after weeks of negotiations, and airport spokesman Juergen Harrer said the airport operator finds the demand for double-digit wage increases "absolutely unacceptable." "This is a small group of workers with the ability to massively limit flight traffic," he said. They are pushing their excessive demands on the backs of the passengers ... and the other workers. He called for the union to return to the negotiating table to work out a compromise. GdF's spokesman did not answer his telephone nor respond to e-mailed requests for comment.