(Reuters) -Low-cost rivals JetBlue Airways and Spirit Airlines have agreed to call off their $3.8 billion merger agreement on Monday after a U.S. judge blocked the deal on anti-competition concerns.

A successful deal would have created the fifth-largest carrier in the United States and helped Spirit secure its survival.

“Given the hurdles to (deal) closing that remain, we decided together that both airlines’ interests are better served by moving forward independently,” JetBlue CEO Joanna Geraghty said.

JetBlue shares rose as much as 7% in premarket trading after the announcement, while Spirit fell 14%.

The ruling by U.S. District Judge William Young found the proposed deal was likely to hurt competition in the U.S. aviation market and could harm ticket prices.

That prompted JetBlue to raise doubts over the future of its deal, saying it might be unable to meet certain conditions required as part of the agreement.

(Reporting by Aatreyee Dasgupta in Bengaluru; Editing by Devika Syamnath and Arun Koyyur)