Spirit Airlines rejects JetBlue’s acquisition offer.

The proposal from JetBlue Airways was unlikely to be approved by the regulators, according to the airlines.

In a letter to JetBlue, the executives of Spirit said that the acquisition offer would not be approved if the partnership with American Airlines was still in effect. The letter said that a recent communication from JetBlue made it clear that the airline is not willing to end the partnership. Several states and the Justice Department have sued to block the partnership, arguing that it is anticompetitive.

In a statement, the chairman of the board of the company said that the company stood by its plan to merge with Frontier Airlines and that it represented the best interests of long-term shareholders.

The board determined that the proposal from JetBlue was not in the best interest of the company's stockholders.

In February, both low-fare airlines announced a plan to combine. Last month, JetBlue stepped in with a bigger offer. Biden administration regulators have expressed more skepticism about consolidation than their predecessors.

Some analysts think that the business model of both Frontier and Spirit is better suited to merging because they have more flights in different parts of the United States. The business models of the airlines are quite different, which could make it difficult to pull off a combination. The deal could allow the airline to compete more effectively.

Regulators are likely to be very concerned with the prospect of higher costs and higher fares for consumers, as a result of JetBlue's offer. The higher prices would result from converting the densely packed planes of Spirit to the roomier planes of JetBlue.

In its response on Monday, JetBlue said it would offer to sell its assets in New York and Boston, two markets that regulators have expressed concern about in their lawsuit seeking to strike down the Northeast Alliance. Frontier has not offered to sell assets or pay a break-up fee, as was argued by JetBlue. The value of Frontier's cash-and-stock deal has faded because of the airline's falling stock price.

The certainty of our substantial cash premium, regulatory commitments, and reverse breakup fee protection would be better forSpirit shareholders.

The low-cost carrier was accused of failing to grant it sufficient access to data while requesting unprecedented commitments from JetBlue.