Spirit Airlines on Thursday rejected Frontier Airlines' latest proposal for a merger, which would have helped bring the Florida-based carrier out of bankruptcy to join forces with its top competitor.

The two airlines have sent proposals and counterproposals during a recent bid from Frontier to take over bankrupt Spirit Airlines.

Spirit Airlines has again rejected a third takeover bid from budget rival and Denver-based Frontier Airlines, saying that it would focus on its own plan to emerge from bankruptcy and stabilize its finances.