Spirit Airlines is preparing to file for bankruptcy protection after merger talks with Frontier Airlines broke down, according to people familiar with the matter. The Florida-based budget airline is in advanced discussions with bondholders to hammer out a bankruptcy plan that would have support from a majority of creditors,

KEY TAKEWAYS Spirit Airlines shares are plunging more than 60% in premarket trading on a report that the budget carrier is getting ready to file for bankruptcy protection after revived merger talks with Frontier Airlines parent Frontier Group Holdings collapsed.

The Miramar, Florida-based discount airline is expected to file for bankruptcy protection from its debts in as little as 10 days or within weeks, sources familiar with the matter confirmed to CBS News. The Wall Street Journal first reported the looming bankruptcy filing.