Spirit Airlines is preparing to file for bankruptcy protection after merger talks with Frontier Airlines broke down, the Wall Street Journal reported, citing people familiar with the matter. Shares of the company were down 39% at $1.8 after the bell. The stock has fallen nearly 80% this year, while the S&P 500 passenger airlines index jumped 52%.

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.