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.

Spirit Airlines is now reportedly in advanced talks over a possible bankruptcy filing following a failed merger and continued financial struggles, The Wall Street Journal reported Tuesday evening. The company had been exploring a merger with another low-cost airline,

The budget carrier is in advanced discussions with bondholders over a filing that could occur within weeks.

Spirit Airlines stock fell by about 36% in afterhours trading after the Wall Street Journal reported that the Florida-based budget airline is in advanced discussions with bondholders to hammer out a bankruptcy plan.

Spirit Airlines is on the brink of filing for Chapter 11 bankruptcy protection following the collapse of its merger talks with Frontier Airlines. With more than $3 billion in debt, Spirit is negotiating with bondholders for a restructuring plan that could allow it to continue operations under bankruptcy protection.

The ultra-low cost airline is gathering assets for a bankruptcy plan, which motions could be initiated in coming weeks.