Spirit and Frontier airlines Wednesday finally pulled the plug on their proposed deal, which had been on life support for months, clearing the way for a possible purchase of Spirit by JetBlue Airways.

The proposed merger of Spirit and Frontier, first announced in February, was never able to capture the support of a majority of Spirit shareholders after JetBlue stepped in with its more lucrative all-cash offer.

But Spirit management continued to push for the Frontier deal, arguing that the JetBlue deal was unlikely to win regulatory approval. A deal for Spirit, which would create the nation's fifth largest airline, would be smaller than many airline mergers of recent decades, which turned the 10 largest US airlines into four mega-carriers that control 80% of US air traffic. But the Biden administration has taken a much more aggressive stance on questions of antitrust law and vowed to promote greater competition within the airline industry.

Spirit and Frontier airlines Wednesday finally pulled the plug on their proposed deal, which had been on life support for months, clearing the way for a possible purchase of Spirit by JetBlue Airways.

The proposed merger of Spirit and Frontier, first announced in February, was never able to capture the support of a majority of Spirit shareholders after JetBlue stepped in with its more lucrative all-cash offer.

But Spirit management continued to push for the Frontier deal, arguing that the JetBlue deal was unlikely to win regulatory approval. A deal for Spirit, which would create the nation's fifth largest airline, would be smaller than many airline mergers of recent decades, which turned the 10 largest US airlines into four mega-carriers that control 80% of US air traffic. But the Biden administration has taken a much more aggressive stance on questions of antitrust law and vowed to promote greater competition within the airline industry.