The largest American coal miner, Peabody Energy, is delaying an interest payment due this week and warned that it may have to file for Chapter 11 bankruptcy protection.
Shares of Peabody Energy Corp. plummeted more than 40 percent before the market opened Wednesday. Its shares have already lost half their value in the last three months.
A slowing global economy and toughening environmental standards have slammed the coal industry, which is already beset by bankruptcies, shuttered mines and layoffs. Many electric power companies have shifted to using natural gas, which costs less than coal and produces less pollution.
Rival coal companies Alpha Natural Resources, Arch Coal and Patriot Coal have all filed for bankruptcy protection in the last year.
St. Louis-based Peabody said it didn't pay more than $70 million in interest payments that were due Tuesday. If the company doesn't make the payment in 30 days, it would default and its said there's "substantial doubt" it would be able to go on.
Peabody had about 7,600 employees at the end of last year and operates mines in Arizona, Colorado, Illinois, Indiana, New Mexico and Wyoming. It also has mines in Australia.