(Reuters) -Spirit Airlines ( SAVE ) is in talks with bondholders over terms of a potential bankruptcy filing in the wake of its failed merger with JetBlue Airways, the Wall Street Journal reported on Thursday, citing people familiar with the matter.

Shares of Spirit were down 18% in after market trading.

Spirit Airlines ( SAVE ) did not immediately respond to a Reuters request for comment.

The report added that the budget carrier has also been exploring restructuring its balance sheet through an out-of-court transaction, though recent talks have been more focused on reaching a deal with bondholders and other creditors to support a Chapter 11 filing.

The timing of such a filing, should it happen, wouldn't be imminent, the WSJ report said.

In June, CEO Ted Christie said the airlines was not considering a Chapter 11 bankruptcy and is "encouraged" by the plan it has in place after the deal with JetBlue fell through.