Power generation companies, including state-run power producer NTPC and Damodar Valley Corporation (DVC), owed a total of about Rs8,279.19 crore in coal payment dues to Coal India Ltd (CIL), as of 30 November.
A CIL official said while NTPC, the country's largest power producer, owed around Rs500 crore to the state-run coal producer, DVC has an outstanding dues of around Rs1,500 crore.
Power companies of states like West Bengal, Chhattisgarh, Rajasthan and Madhya Pradesh also owe large amounts to CIL, the official added.
NTPC official say the dues is negligible and could be short-term and that the power utility has not received any communication in this regard.
"NTPC's negligible amount may be due with Coal India, which is a routine matter," the official said.
It is DVC and state discoms which owe significant outstanding dues to CIL and both are facing tough financial conditions, sources pointed out.
"So this is can be seen as one of the reasons for the power generation firms owe huge dues to Coal India," the CIL official said.
In order to ease the financial crunch of power distribution companies or discoms that has impaired their ability to buy electricity, the union government had last month approved a scheme to recast Rs4,30,000 crore of debt of the utilities.
The centre also unveiled a rescue plan, called Ujwal Discom Assurance Yojna or UDAY to revive ailing state electricity boards and improve operational efficiencies of power distribution companies.