March 17 James River Coal Co, which is grappling with a liquidity crunch, said it would not make the interest payment due on Monday on $230 million of its convertible senior notes.
The company's shares fell about 14 percent in trading after the bell.
James River, which had a long-term debt of $425.4 million as of Sept. 30, said the 3.125 percent convertible senior notes would mature in 2018.
The company said in a regulatory filing that it had 30 days to make the payment to avoid a default.
James River also said it had delayed regulatory filing of its results for the quarter and year ended Dec. 31 as it was exploring selling itself, among other strategic alternatives.
The coal miner said last month that it was exploring strategic alternatives.
James River said on Monday its auditors warned that an audit of its results would qualify it as a going concern due to its liquidity crunch.
The company idled seven mines in Central Appalachia in eastern United States between September and November as weak demand and excess supply weighed on prices of both metallurgical and thermal coal for the past year or so.
James River had $60.2 million of cash and cash equivalents as of Sept. 30.
The company's shares closed at 70 cents on Monday on the Nasdaq.