JetBlue Airways (JBLU  ) is attempting a hostile takeover of Spirit Airlines (SAVE  ) after the budget carrier rebuffed it's much more lucrative offer of a merger.

JetBlue issued a proxy statement to Spirit shareholders urging them to vote no on the upcoming proposition to merge with fellow low-cost airline Frontier Group (ULCC  ). According to the company's Business Wire release, JetBlue is offering Spirit shareholders $30 per share as a counter-offer (for reference, Spirit opened at $19.47 per share on Tuesday). Additionally, JetBlue has left the door open to resume negotiations for its original "enhanced" offer that Spirit's board of directors turned down.

"JetBlue offers more value - a significant premium in cash - more certainty, and more benefits for all stakeholders," CEO Robin Hayes wrote in the proxy letter. "Frontier offers less value, more risk, no divestiture commitments, and no reverse break-up fee, despite more overlap on non-stop routes and their own regulatory challenges. Yet the Spirit Board failed to provide us the necessary diligence information it had provided Frontier and then summarily rejected our proposal, which addressed its regulatory concerns, without asking us even a single question about it."

JetBlue's initial offer to acquire Spirit followed a failed bid to purchase Virgin America, subsequently purchased by Alaska Airlines (ALK  ). However, the battle to acquire Spirit possesses more significant risks and payoffs; regardless of who acquires the airline, the resulting combined company would be the fifth-largest carrier in the U.S.

While both Frontier and JetBlue stand to benefit from a merger with Spirit, only the former possesses overlap with the budget carrier's business model. Frontier would inevitably be more capable of adequately merging itself with Spirit, though JetBlue would still gain access to a much larger fleet of narrow-body aircraft, as well as a pool of pilots capable of flying them. Given that most airlines are left scrambling for pilots amid a labor crunch, JetBlue still stands to gain quite a bit from a potential acquisition despite its lack of overlap with Spirit.

JetBlue's share price slid 4.5% on Monday, though any anxiety investors had seemed to be mostly gone on Tuesday, with shares up 6.7% by noon. Spirit shares have been on a more steady climb, rising 4.6% on Monday and an additional 0.78% by noon on Tuesday.