According to an official, the auction will be conducted for four days beginning Thursday.
"The auction will be conducted on October 20, 21, 24 and 25," the official said.
The total validity for lifting of coal under the special spot auction window will be up to March 2017, the official added.
The reserve price will be limited to the upper cap of 20 per cent add-on over the notified price of coal for the non-power sector, the official said.
"The minimum quantity for bidding would be 50 tonnes and bid multiple would be in the multiple of 50 tonnes... whereas in the case of rail, the minimum quantity of bidding would be one rake and bid multiple would be in the multiple of one rake," he said.
The rake size shall be as per prevalent railway rules. The quantity of coal in a rake will be as indicated in the notice of e-auction of coal companies.
State-owned CIL had last month announced a one-time offer of 20 MT of coal under a special spot e-auction in the ongoing fiscal year.
The Coal Ministry had earlier said power producers being supplied coal through the MoU route by CIL will have to take it via special e-auction being conducted for the power sector.
CIL, a major supplier of coal to the power sector, is eyeing production of one billion tonne by 2020.