Stock futures were down around 40% at $1.35 by 0645 in New York before markets opened, having already dropped by 86% so far this year.

According to the Wall Street Journal late on Thursday, the company is in discussions with its bondholders over debt maturities due in 2025 and 2026.

Talks have been centred around a possible chapter 11 filing, the article said, citing people familiar with the matter.

The company has been attempting to restructure its balance sheet and $3.3bn debt pile following the failed $3.8bn merger with JetBlue Airways earlier this year, after it was blocked on competition concerns.