Lufthansa flight attendant union said it would announce several strike actions July 1 if an agreement has not been reached by June 30 over pay and pension benefits. On Saturday, arbitration between Lufthansa and UFO ended without an agreement.

Head of UFO Nicoley Baublies said at a press briefing Monday that if Lufthansa does not offer an improved retirement plan solution by the June 30 deadline, the union will announce several strike dates July 1. UFO will then plan several strike actions throughout the summer season until Sept. 16, it said.

A Lufthansa spokesperson told ATW on Friday the company would like to go ahead with the arbitration. Last week, Lufthansa said in a statement that it had presented a much better transition offer on payments for early retirees.

The UFO union represents 19,000 flight attendants.

Lufthansa was hit with 12 pilot strikes in 2014 and early 2015, the company said in its first quarter 2015 results presentation. Flight cancellations caused by pilot strikes Vereinigung Cockpit (VC) led to a burden of €42 million ($48 million), Lufthansa said in its first-quarter earnings statement. Last year, strikes called by VC cost the German carrier €230 million.