Spirit Airlines rejected a $400 million merger proposal from Frontier this week, saying the offer was financially inadequate and came too late. Spirit Airlines declined an opportunity to merge with rival low-cost airline Frontier on Wednesday.

Frontier Airlines hoped to create a low-cost airline giant, but Spirit isn’t interested—at least, not at this price. Spirit Airlines has rejected a merger offer with Frontier as it prepares to exit bankruptcy.

Spirit Airlines rejected Frontier Airlines’s second merger bid, opting to continue on its current path to emerge from bankruptcy. The low-cost airline filed for bankruptcy last year after the Justice Department blocked a proposed merger with JetBlue.