A German trade union representing cabin attendants said on Friday it had contacted Lufthansa for fresh talks, as a 24-hour strike that has grounded 1,000 scheduled flights round the globe affected thousands of passengers.

Lufthansa called its contact with the Ufo labour union “tentative,” and declined to confirm a report on ZDF public television that the two sides were close to appointing an outside mediator to bridge their differences over pay and job protection.

The dispute has snarled travel for an estimated 100,000 travellers.

A small number of long-haul flights also went ahead, with non-strikers serving passengers. The stoppage, the biggest ever by the airline’s attendants, was preceded by two shorter strikes.

Lufthansa’s terminal at its main hub in Frankfurt was quieter than usual, after passengers were warned by text message that their flights had been cancelled or that they would be given tickets on other airlines.

The union says it is not planning any further strikes yet. The airline is expected to resume normal operations on Saturday.

Despite claims on both sides that they are ready to talk, there are no signs of any actual concessions after 13 months of fruitless talks. The union is opposed to Lufthansa plans to set up low-pay subsidiaries.

Nicoley Baublies, leader of the union, said: “Since we contacted them first, we expect Lufthansa to offer a shift on the issues.” A Lufthansa spokesman said both sides had agreed to keep the content of their latest contacts confidential.

Lufthansa says it has 18,000 flight attendants, while the union counts 19,400 airline staff as belonging to the attendant category.

UFO union is demanding a 5-per-cent pay rise. Lufthansa is offering 3.5 per cent but insists on establishing a new low—wage budget airline.

Lufthansa has cancelled about two-thirds of its flights after cabin crews walked off the job at airports around the country in an escalating battle with Germany’s largest airline.

The dispute comes as Lufthansa struggles to fend off challenges from budget carriers and government-owned airlines in the Persian Gulf.