Discount carrier says a merger would be a better path out of bankruptcy for Spirit, which has rebuffed the latest proposal.

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.

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.