Air France’s leading pilots union on Sunday announced an end to a 14-day strike that grounded roughly half of the airline’s flights, stranded passengers worldwide and led to stern shows of frustration by the French prime minister.

After a late-night negotiating session with management, leaders of the SNPL pilot union walked away with no deal, but the realization that the strike “is not an end in itself,” said union spokesman Antoine Amar. The union was “taking up its responsibilities” and ending the walkout so that service can now resume and negotiations can continue peaceably, he said.

At the center of the standoff were 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.

Pilots said they 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.

Air France declined immediate comment.

In a tactical retreat, the carrier 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.

Several would-be passengers interviewed by The Associated Press expressed frustration and anger during the strike; some grumbled about the tendency of many French workers to strike — and snarl services in the process. Socialist Prime Minister Manuel Valls chimed in during the walkout, saying the strike was unfounded, incomprehensible to the French people, endangered the flag carrier and gave France a “bad image.”

Parent company Air France-KLM said previously that the walkout was costing up to 20 million euros ($25 million) a day.

(AP)