JetBlue Airways announced Thursday morning it plans to buy Spirit Airlines for $3.8 billion, a merger that could have significant impacts on  both Palm Beach and Fort Lauderdale international airports.

The deal would create the nation’s fifth-largest airline. Spirit had recommended its shareholders approve a lower offer from Frontier Airlines, saying that regulators are likely to reject the bid from JetBlue. Spirit executives, however, reversed course Wednesday after it became clear that shareholders would not approve the Frontier offer.

At Fort Lauderdale-Hollywood International Airport, Spirit was the top carrier from January through May 2022, capturing a 28% passenger share; 3.7 million passengers flew on its planes. JetBlue was second with a 21% share. The two airlines together account for nearly 50% of all traffic.

At PBIA, travelers can get rates on Spirit as low as $126 for round-trip flights to Atlantic City or Newark, New Jersey, in the winter.

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Spirit and JetBlue will continue to operate independently until after the transaction closes. JetBlue will oversee operations from its New York offices.

Frontier executives have already said they expect to move in aggressively to compete with JetBlue at airports where they raise fares on Spirit flights. Those sweet $40 roundtrip fares on Spirit may soon be a thing of the past.

Frontier quickly pivoted from the Spirit merger on Wednesday, offering one-way fares for as low as $19.

Jeff Miller, an aviation lawyer based in Maryland who taught for 15 years at Florida Atlantic University, says a Spirit-JetBlue merger will lead to higher fares, including the South Florida airports. The question is how much.

He noted it will be costly for JetBlue to retrofit Spirit planes so that passengers accustomed to the JetBlue experience will continue to receive that experience. Spirit seats don’t recline, and there is very little legroom.

“A lot of people go on Spirit once and say 'Never Again,' ” he noted. “You get what you pay for.”

Miller said most people take stored luggage with them and choose their seats ahead of time. "You do that on Spirit and you may not be that far below what JetBlue charges," he noted.

Why is the JetBlue-Spirit merger happening?

As for why JetBlue wants to buy Spirit, Miller said Jet Blue needs their planes, pilots and flight attendants. There will be considerable savings by achieving economies of scale, he noted.

JetBlue anticipates $600 million to $700 million in annual savings once the transaction is complete.

Henry H. Harteveldt, a travel industry analyst with Atmosphere Research Group, sees the merger as a benefit to PBIA. He noted Avelo Airlines and Breeze Aviation Group already fly out of there on a limited basis and may well increase their presence if the merger is approved.

At PBIA, JetBlue was the No. 1 carrier with a 26% share of passengers from January to June 2022. Spirit had just 1% share.

Both Hartveldt and Miller say that to obtain regulatory approval, JetBlue will have to make major concessions such as giving up gates and ticket-counter space at several Northeast airports. “They will do whatever they have to do to get this approved,” Hartveldt said.

The Justice Department is already suing JetBlue and American Airlines to prevent a partnership between those airlines at airports in Boston and New York, with the trial scheduled for early this fall.

Frontier, according to Hartveldt, will be a much stronger airline as it will be the only major discount operator. As of 3 p.m. Thursday, its stock was up 6.4%; Spirit Airlines was up 1.4% and JetBlue was down .36%.

And JetBlue will be in a better position to compete with the legacy airlines, Harveldt noted.

But he sees Frontier as the big winner.

“It doesn’t have to worry about pursuing the merger any longer and can increase its capacity as it takes over routes abandoned by Spirit,” Hartveldt said.

Mike Diamond covers Palm Beach County government and transportation. If you have a tip, he can be reached at mdiamond@gannett.com. Follow him on Twitter at @michael06339386.

This article originally appeared on Palm Beach Post: JetBlue/Spirit merger: How it will affect South Florida prices