The determination was based on “abnormally low” price indications of the company's common stock.

The company said it expects that its common stock will begin to trade on over-the-counter markets beginning on July 17, 2015.

Shares in Alpha Natural Resources have tumbled on the back of speculation it could file for bankruptcy protection next month.

The shares went down 33% in after hours trade on Wednesday in response to the news flow.

“Alpha Natural Resources Inc. is in talks to obtain financing for a potential bankruptcy filing early next month as it grapples with a severe downturn in coal prices, according to people familiar with the matter,” the Wall Street Journal reported.

The newspaper claimed that Alpha was negotiating the terms of a $300-400 million debtor-in-possession loan with its loan holders and senior bondholder.

A chapter 11 filing, while reportedly not considered inevitable, was flagged for early August when convertible bonds came due.

Alpha shares struggled to stay above US24c in trading yesterday, near the bottom of their 20c to $4.16 52-week trading range.

Employees at three Alpha subsidiaries have been warned that their work places may be sold off by the troubled US coal producer last week.

In accordance with requirements of the Worker Adjustment and Retraining Notification Act, the operators have given notice to 292 employees at six mines and a processing plant in southwest Virginia and eastern Kentucky of the expected idling of those facilities in anticipation of their potential sale.

Alpha is the second company to be delisted from the NYSE in recent weeks, following the announcement that Walter Energy would be delisted.