(Reuters) -Spirit Airlines is in constructive discussion with its creditors and continues to explore strategic alternatives to improve liquidity, the ultra-low-cost carrier said on Tuesday. The negotiations, with a supermajority of the noteholders, have remained productive, advanced materially and are resuming in the near term, it added.

Spirit Airlines Inc. is preparing to file for bankruptcy protection after merger talks with Frontier Group Holdings Inc. broke down, the Wall Street Journal reported.

Spirit Airlines is preparing to file for bankruptcy protection after merger talks with Frontier Airlines broke down, the Wall Street Journal reported, citing people familiar with the matter. The ultra-low cost carrier is in advanced discussions with bondholders to hammer out a bankruptcy plan that would have support from a majority of creditors,