In a quick conclusion to a months-long battle, JetBlue Airways has reached a $3.8 billion deal to buy Spirit Airlines. If approved, the takeover would create America’s fifth-largest airline.

The deal was announced hours after Spirit cited lack of shareholder support for its decision to drop plans to merge with fellow discount carrier Frontier Airlines.

If regulators agree to the deal, the combined JetBlue/Spirit would have a fleet of more than 450 aircraft, with 1,700 daily flights to 30 countries. Frontier would be left as the largest discount carrier in the U.S.

“We believe we can uniquely be a solution to the lack of competition in the U.S. airline industry and the continued dominance of the Big Four,” JetBlue CEO Robin Hayes said in a statement in a reference to the country’s top four airlines: American, United, Delta and Southwest.

“By enabling JetBlue to grow faster, we can go head-to-head with the legacies in more places to lower fares and improve service for everyone.”

JetBlue says the combined fleet would help it compete with the Big Four, which control most of the U.S. market.

Spirit’s bright yellow planes would be refurbished n JetBlue style and feature signature elements including seatback screens and more legroom.

JetBlue said it will pay $33.50 a share in cash for Spirit, substantially more than the $2.6 billion cash and stock proposal from Frontier.

“We have two priorities: one is to get this deal closed and get the airline integrated and build a bigger JetBlue,” JetBlue CEO Robin Hayes told CNBC Thursday. “Secondly to run a reliable operation in the meantime.”

Hayes would be in charge of the combined airline, which JetBlue said would remain headquartered in New York City.

The two airlines are hoping the deal will close in the first half of 2024 and they expect to be able to fly on the same operating certificate in the first half of 2025.

Frontier shareholders are still winners, as shares surged more than 20% to $13.58 on Thursday.

“Should a JetBlue-Spirit merger occur, we believe Frontier will largely inherit the keys to the low-cost kingdom in the U.S.,” JP Morgan airline analyst Jamie Baker wrote in a note Thursday.

While this is the first major deal in U.S. aviation since 2016, a wave of consolidation in the decade prior left the big four U.S. airlines in control of about three-quarters of the domestic air travel market.