Frontier says a merger would be a better path out of bankruptcy for Spirit, as budget carriers struggle with high costs and competition.

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.

Frontier Airlines is attempting for a second time to merge with the now bankrupt Spirit Airlines, which declared bankruptcy late last year as budget airlines struggle.