Spirit Airlines files for bankruptcy, will continue to operate as it restructures debt, airline says

NEW YORK -- Spirit Airlines filed on Monday for Chapter 11 bankruptcy protection, months after a federal judge blocked the budget airline's proposed merger with JetBlue.

The company, which is based in Florida, published on Monday an open letter to those who've booked tickets for the future. Flights, ticket sales and other operations will continue as normal, the airline said.

"The most important thing to know is that you can continue to book and fly now and in the future," the letter said.

The airline filed in U.S. Bankruptcy Court for the Southern District of New York, saying in an accompanying press release that it sought to restructure and reduce its debt.

JetBlue and Spirit had proposed a merger, signing an agreement in July 2022, a deal that the discount airlines said would improve their ability to attract customers away from larger competitors.

But they jointly announced in March 2024 that they would terminate the deal, saying they were unlikely to gain legal and regulatory approval prior to the July 2024 merger deadline. The Department of Justice had sued to block the merger.

A supermajority of the company's bondholders had voted in favor of the bankruptcy filing, CEO and President Ted Christie said in a statement on Monday.

He positioned the restructuring as a "vote of confidence" in Spirit and its long-term planning.

"This set of transactions will materially strengthen our balance sheet and position Spirit for the future while we continue executing on our strategic initiatives to transform our Guest experience, providing new enhanced travel options, greater value and increased flexibility," he said.

Spirit said it expects the restructuring process to be completed by the first quarter of 2025. The airline's shares, which trade under the SAVE ticker, slipped more than 60% last week.

The Federal Aviation Administration said in a statement that its oversight of airlines includes assessing "significant changes in the operating environment, which could include financial distress."

"We have been continuously evaluating Spirit Airlines through our regular oversight process to ensure its resources, size, and organizational structure enable it to meet all operational requirements," the FAA said.

ABC News' Ayesha Ali contributed to this report.