× Thanks for reading! Log in to continue. Enjoy more articles by logging in or creating a free account. No credit card required. Log in Sign up {{featured_button_text}}

The New York Stock Exchange suspended trading in Cloud Peak Energy on Tuesday due to the Gillette-based coal company’s sustained low stock price.

Cloud Peak Energy was warned in December that the exchange would delist the firm if the stock price — which had been trading under $1 per share for 30 days — didn’t improve within six months. The firm chose not to pay a recent debt payment, which if not paid within 30 days will place the company in default. The choice has been noted as a potential precursor to a bankruptcy filing.

Cloud Peak was trading at just 16 cents per share Tuesday.

A call to the company’s spokesman for comment was not immediately returned.

Cloud Peak operates the Antelope and Cordero Rojo mines in Wyoming and the Spring Creek mine in Montana. It employs about 20 percent of the full-time miners in Wyoming’s Powder River Basin coal sector.

Cloud Peak has been increasingly unstable in the face of higher costs and operational challenges. Its margins — the revenue remaining after production costs have been subtracted — fell dramatically from $2.30 per ton in 2017 to 92 cents per ton in 2018.