The New York Stock Exchange suspended trading of Cloud Peak Energy Inc. shares March 26 and announced it initiated the delisting process for the troubled Powder River Basin coal producer based on its "abnormally low" price levels, according to an exchange release.

NYSE's plan to delist Cloud Peak will be forwarded to the U.S. SEC, including the company's appeal to the stock exchange's decision.

The pure-play Powder River Basin coal miner said in a March 15 securities filing that it might file for Chapter 11 bankruptcy within a month.