Spirit Airlines shares slumped 40% before the bell on Friday after the Wall Street Journal reported that the ultra-low-cost carrier was in talks with its bondholders about a potential bankruptcy filing.

The stock has lost more than 85% of its value this year as the carrier struggled with the fallout of a failed $3.8-billion-merger with JetBlue Airways.

Spirit's long-term debt and finance leases amounted to approximately $3.06 billion, excluding current maturities, as of Dec. 31.

The timing of such a filing, should it happen, would not be imminent, according to the report.

The airline, which has failed to report a profit in five out of the last six quarters, also had to ground several Airbus planes due to problems with the Pratt & Whitney geared turbofan engines.

The company has flagged a steeper loss in the third quarter due to what it called an "intense competitive battle" for price-sensitive leisure travelers and an oversupply of airline seats in the domestic market.

Spirit CEO Ted Christie had in June shrugged off concerns of a potential Chapter 11 bankruptcy and said he was "encouraged" by the plan it had in place after its JetBlue merger fell through.

(Reporting by Pratyush Thakur in Bengaluru; Editing by Leroy Leo)