Shares of Frontier Airlines and Spirit Airlines tumbled Monday after their improved merger proposal won a key endorsement just days ahead of a crucial shareholder vote.
Frontier CEO Barry Biffle said Monday that he is optimistic Spirit shareholders will approve Frontier’s latest stock-and-cash offer for Spirit when they vote Thursday.
“I think we have a lot of momentum, so we feel really good,” Biffle said in an interview.
Frontier is trying to fend off an attempt by JetBlue…