Scandinavian airline SAS and the unions representing their pilots said on Tuesday they had reached a wage deal, ending a 15-day strike.

The action over a new collective bargaining agreement had grounded 3,700 flights and cost the ailing airline between $9 million and $12 million a day, throwing the carrier’s future into doubt.

SAS, which filed for U.S. bankruptcy protection on the second day of the strike, said the strike had cost it more than $145 million to date and affected 380,000 passengers in the peak summer travel season.

The agreement came after a negotiation session ran through Monday and into the early hours of Tuesday.

The labor strife was the latest across Europe’s aviation sector as millions of workers struggle with rising costs of living, prompting trade unions to demand higher wage increases and stage walkouts and disrupting travel.

Even before the pandemic hit, SAS was losing money amid rising competition from low-cost carriers. The company’s biggest owners are Swedish and Danish taxpayers.

The airline said the new 5-1/2-year deal with four pilot unions would help it achieve part of the $700 million of annual cost savings set out in a business transformation plan that also includes such measures as handing back unwanted planes to lessors.

"Finally, we can resume normal operations and fly our customers on their much longed-for summer holidays," SAS CEO Anko van der Werff said in a statement.

"I deeply regret that so many of our passengers have been impacted by this strike."

Some flight disruptions will continue while the airline works to resume normal traffic, the company said.

"SAS pilots have taken responsibility to sign a new agreement with SAS and the strike will cease," the Swedish Air Line Pilots Association (SPF) said in a separate statement, adding that it had been "an extraordinary and very demanding negotiation."

Pilots have been striking since July 4, when nearly 1,000 of them walked off the job after talks broke down.

They were protesting against salary cuts demanded by management as part of a restructuring plan aimed at ensuring the survival of the company, and the firm’s decision not to rehire pilots laid off during the coronavirus pandemic.

SAS said the agreement with pilots involved higher productivity, increased flexibility in seasonal capacity and a commitment, as operations ramp up until 2024, to rehire 450 pilots laid off during the outbreak.

The deal will allow the airline to finalize plans in the next few weeks to raise $700 million of fresh financing needed to see it through the bankruptcy protection process, the company said.

SAS added the final deal remained subject to approval by unions and a U.S. federal court. It expected to receive that approval within a few weeks.

The U.S. Chapter 11 bankruptcy protection process is expected to last for nine to 12 months, the airline has said previously.