JetBlue Airways has warned Spirit Airlines it may not be able to complete its proposed $3.8 billion takeover of the South Florida-based discount carrier for unspecified reasons, and raised the possibility the deal could be terminated by as early as this weekend, according to regulatory filings made public Friday.

The New York discount carrier suggested without elaboration that there may be grounds to end the deal as early as Sunday.

The disclosures severely depressed Spirit stock in Friday trading, as the shares for the Miramar-based airline plunged by 13.4% to $6.25. Its 52-week high was $18.34.

But Spirit responded it sees no reason to end the transaction, which was approved by shareholders in 2022, but derailed this month by a federal judge after the U.S. Justice Department and several states sued to stop the combining of the two airlines for antitrust reasons.

After U.S. District Judge William Young of Boston ruled following a bench trial, the two airlines filed a joint notice of appeal. In the meantime, they said the agreement between them remained in effect.

That stance appeared to change on Friday when the carriers in separate SEC filings disclosed JetBlue had informed Spirit there may be grounds to end the deal. JetBlue did not elaborate.

Spirit: “No basis” for termination

“This morning, JetBlue Airways Corporation (“JetBlue”) filed a Form 8K stating that JetBlue yesterday informed Spirit that certain conditions to closing required by the Agreement and Plan of Merger, dated as of July 28, 2022, among JetBlue, Spirit and Sundown Acquisition Corp. …. may not be satisfied prior to the outside dates set forth in the Merger Agreement,” Spirit said in a Friday filing with the Securities and Exchange Commission.

The airline also said it had been informed by the New York-based carrier that “the Merger Agreement may be terminable on and after January 28, 2024.”

The carriers had hoped to close their deal in the first half of this year.

Both said JetBlue “continues to evaluate its options under the Merger Agreement” and would continue “to abide by all of its obligations” under the deal.

But Spirit in its filing said it sees no reason for killing the agreement.

“Spirit believes there is no basis for terminating the Merger Agreement,” the airline said. “Spirit will continue to abide by all of its obligations under the Merger Agreement, and it expects JetBlue to do the same.”

Neither airline had anything to add beyond their filings by the end of the business day Friday.

Judge Young’s ruling raised doubts among Wall Street industry analysts about Spirit’s ability to survive as an independent carrier without a financial restructuring in bankruptcy court. Spirit management replied it had no intention of pursuing a court-supervised reorganization.

But the airline, which has not earned a profit since 2019, said it is exploring options to refinance debts that come due next year. Overall, Spirit is carrying $4 billion in debt.

For its part, JetBlue is also losing money, and analysts have said it would come under even more financial pressure if it acquired Spirit. Robin Hayes, the carrier’s outgoing CEO, has said the airline would have to borrow $3.5 billion to complete a takeover of Spirit because it would assume all of Spirit’s debts.