PARIS (AP) ― Despite no deal in sight, Air France’s main pilots union on Sunday unilaterally ended a 14-day strike that grounded roughly half of the airline’s flights, stranded passengers worldwide, cost tens of millions of dollars and led France’s prime minister to decry a “selfish” walkout.

After a late-night, 15-hour negotiating session with management, leaders of the SNPL pilot union walked away with no accord, but with the realization that the strike “is not an end in itself,” union spokesman Antoine Amar said. In a later statement, the union said it was ending the strike “in the interests of the company and passengers.”

The walkout, which began Sept. 15, was the longest in more than four decades initiated by pilots at Air France, union official Guillaume Schmid said. The 81-year-old company today conducts about 1,500 flights each day, and last year had 77.3 million passengers, making it one of Europe’s biggest carriers.

Air France, in its own statement, said service would “progressively” start returning to normal on Tuesday ― meaning that flights already canceled between now and then won’t be reinstated. The company hailed the end of the strike, saying it “will have been costly and damaging. It has only lasted too long.”

Alexandre de Juniac, chairman and CEO of parent company Air France-KLM, said management team members “are aware of the trauma that our customers, employees and partners just lived through,” according to the statement. It said full service was likely to resume late this week.

At the center of the standoff are Air France’s ambitions to develop a low-cost affiliate, Transavia, to tap into new markets in both France and elsewhere in Europe and better compete at a time when budget airlines have cut into the market share once dominated by giant European carriers like Air France.

The pilots union said it didn’t oppose those plans to build the new business, but rejected the labor conditions that management had planned. They started the strike two weeks ago out of concerns that management was looking for a way to outsource their jobs to countries with lower taxes and labor costs.

In a tactical retreat, the carrier’s management offered Wednesday to scrap a central part of the plan to shift most of its European operations to Transavia. But the pilots remained unsatisfied, saying the contracts sought for the low-cost carrier’s operations in France alone were insufficient.

Air France, in its statement, “confirmed its decision to continue its accelerated development of Transavia in France, without delay” ― which suggested that issues remain unresolved. The carrier said it is sticking to plans to create 1,000 jobs in France through Transavia carrier, including 250 pilot positions.