Frontier Airlines is exploring a renewed bid for Spirit Airlines, people familiar with the matter said, as Spirit continues discussions with bondholders over the terms of a potential bankruptcy filing.

Spirit Airlines Inc. is in talks with Frontier Group Holdings Inc. about filing for bankruptcy to facilitate a takeover by the rival discount carrier, according to people with knowledge of the matter.

For the past eight years, in fact, Spirit Airlines and Frontier Airlines have been the will-they-or-won’t-they couple of the airline industry, having repeated merger discussions