The Toronto-based explorer owns thermal properties in central Appalachia including eastern Kentucky and said accompanying discussion and analysis and all related chief executive certifications and information forms would also not be filed within the regulated time period.

“The indefinite delay … will occur as a result of the company’s current inability to fund the operation of its business, including the costs of completing the 2011 annual filings,” officials said.

Last month, citing weak thermal coal prices as well as repayment obligations and operational costs, Royal said it would decrease its workforce and idle production at the Big Branch mine in Kentucky.

A relatively new player in North American coal, Royal said it wanted to refocus its efforts to reduce expenditures, raise capital, refinance debt and establish positive cash flow.

Big Branch contains 5 million tons of recoverable proven or probable coal, while its sister mine Sid is a production-ready project with 3.3Mt proven or probable.

Both sites are located near Hazard in Kentucky.