Spirit Airlines said Monday it has filed for Chapter 11 bankruptcy protection after struggling with losses, growing debt and a failed merger during the post-pandemic travel lull.

The company said in a stock market statement that it had secured a prearranged deal with bondholders that includes $300 million in financing to keep it afloat, with the business planning to end its bankruptcy in the first quarter of 2025.

Flight ticket sales and all other operations will continue as normal, the…