JetBlue calls it quits with American Airlines in a bid to advance Spirit Airlines acquisition.

In a bid to safeguard its projected $3.8 billion acquisition of Spirit Airlines, JetBlue Airways announced on Wednesday its intention to comply with a U.S. judge's order from May, calling for the termination of its alliance with American Airlines.

Despite "strongly" disagreeing with the court's ruling, the New York-based airline has decided against appealing the decision. JetBlue disclosed that it had informed American last week about its resolution to dismantle the three-year-old partnership, a collaboration that enabled flight coordination and revenue pooling between the two carriers.

American Airlines, the largest U.S. airline by fleet size with JetBlue ranking sixth, declared its intention to appeal the court's ruling on Wednesday.

JetBlue contends that the decision to dissolve its association with American renders the U.S. Justice Department's (DOJ) opposition, which triggered a lawsuit to obstruct its merger deal with Spirit, as "completely irrelevant". The proposed merger would represent the most significant transaction in the U.S. airline industry since the fusion of American and US Airways in 2013.

CEO Robin Hayes, in an internal memo, remarked that the decision "will enable us to focus even more on our combination with Spirit". The DOJ, when approached by Reuters news agency, opted not to comment.

However, Andre Barlow, an antitrust attorney at Doyle, Barlow & Mazard PLLC, expressed skepticism that the termination of the alliance would sway JetBlue's chances in the legal dispute over the Spirit deal. He asserted, "I don't think it helps. It's even better for the DOJ."