Spirit Airlines has filed for Chapter 11 bankruptcy protection following significant financial struggles due to mounting losses and debt maturities, the airline announced Monday.

The filing comes after two failed mergers in less than two years – one recently with Frontier and another earlier in 2024 with JetBlue – which left the ultra-low-cost carrier in a bind after repetitive quarterly losses.

In October, Spirit announced plans to sell multiple aircraft and lay off workers as it tried to raise cash and revive operations.

Spirit Airlines President and CEO Ted Christie said the airline has entered into an agreement with its bondholders that is expected to reduce the company's total debt and provide increased financial flexibility.

"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," Christie said in a news release. "I'm extremely proud of the Spirit team's hard work and dedication, which is key to our sustained progress in advancing our business and delivering for our guests."

The airline said guests can still book flights and fly as normal, and all tickets, credits and loyalty points can also be used as normal.