NYTimes, Frontier outbid by JetBlue for SpiritFrontier's bid for Spirit was about $1B short, but Spirit management had preferred Frontier.
https://www.nytimes.com/2022/07/28/business/jetblue-spirit-merger.html "The agreement is a victory for JetBlue, which successfully spoiled a rival offer: Frontier Airlines and Spirit had announced merger plans in February, but they called that deal off on Wednesday, after Spirit struggled to convince its shareholders to back the offer, which fell short of JetBlue’s by about $1 billion".
Frontier signed with Flyht in Dec. 2021.
There is some question as to whether or not the U.S. government will allow the deal, but this is nothing to count on, I expect. Details in the article...