Lufthansa CEO says resolution of pilot talks unlikely before Sept

The pilots have held a series of strikes since April 2014, costing the airline over 300 million euros ($326 million) in lost profit in an increasingly bitter dispute.

Last month, the Vereinigung Cockpit union proposed concessions, including agreeing to an increase in the average retirement age and lowering costs. They said they hoped a deal to be reached by the start of September.

"It's very positive that VC has come to us for the first time in years of negotiations with a proposal that includes cost cuts," Carsten Spohr told journalists at event hosted by the Frankfurt ICFW press club.

But he said reaching an agreement by the start of September was unrealistic due to the complexity of the topics involved.

Analysts expect one sticking point will be the pilots' request that the pilots working for the new Eurowings budget unit should be on a German collective labor agreement.

Management wants Eurowings to have operating costs around 30-40 percent lower than that of its main Lufthansa brand, to be at a level more comparable with easyJet .

"(Their offer) has meant that we are in talks," Spohr said. "And only via talks can we solve this conflict."

(Reporting by Peter Maushagen; Writing by Victoria Bryan; Editing by Maria Sheahan)