The floor price for the stake sale will be announced on Thursday after market hours, said Disinvestment Secretary Haleem Khan, adding that the sale will be done via auction that will take place between 9:15 am and 3:30 pm on November 23.
Oil India or NMDC will be divested before December 20, while the stake sale of NTPC may happen in January 2013, said Haleem Khan.
Earlier, the government had set November 21 as the date for divesting stake in Hindustan Copper.
On September 14, the government had approved disinvestment of 9.59 per cent equity of Hindustan Copper through an offer for sale of shares through stock exchanges.
Meanwhile, Mines Minister Dinsha Patel said today that the stake sale will be done in two tranches and the sale of the remaining 5.59 per cent stake will be announced later.
Post disinvestment, the government's shareholding would come down to 90 per cent in the company, whose paid up capital was Rs. 462.61 crore as on March, 2012.
In 2011-12, the leading domestic copper producer had reported its best ever net profit at Rs. 323.44 crore, while its net sales stood at Rs. 1,489.61 crore.
The government, which is aiming to garner Rs. 30,000 crore by divesting its shares in the central PSUs in the current fiscal, has not launched a single share sale so far.
Last month, the government had indefinitely deferred the initial public offer (IPO) of Rashtriya Ispat Nigam Ltd due to differences with the merchant bankers over the price band of the issue.
During the current fiscal, it also aims to sell shares in NALCO, SAIL, MMTC, NMDC and Oil India among others.