The issue price of Rs 21.75 is at a discount of 5.64 per cent to today's closing price of Rs 23.05 on BSE.
"The NHPC OFS will happen tomorrow at a floor price of Rs 21.75 a share," a government official said.
The government holds 85.96 per cent in NHPC and selling over 125 crore shares or 11.36 per cent would help it comply with minimum public shareholding norms.
The government has already lined up over a dozen PSUs for stake sale in the current fiscal.
NHPC would be the third PSU to be sold under the new offer for sale rules notified by market regulator, Sebi. While institutional investors would bid in the first day of the OFS, the retail investors would get to bid on the second day.
NHPC, under the administrative control of power ministry, is engaged in generating power through conventional and non-conventional sources and is dedicated to the planning, development and implementation of an integrated and efficient network of power projects in India.