The government is offering about 428 million of its shares in ONGC on Thursday, which will reduce its stake in the company from about 74 per cent at present to 69.1 per cent.

The state run oil maker has a market value of more than $49 billion. The stake sale, which will help the government get closer to achieving its target of generating Rs 40,000 crore from disinvestments, will happen on Thursday.

The floor price for the auction has been fixed at Rs 290 per share, according to the company. Petroleum and Natural Gas Minister, S Jaipal Reddy had said earlier this week that the government is planning an auction route for disinvesting its stake in ONGC.

The Securities & Exchange Board of India has already said that it will allow the top 100 companies by market value in the country to raise money by selling stake. According to experts, the invetors will be able to participate in the stake sale just like in any other secondary share offer, but the government would save time and money.

Citigroup, Bank of America Merrill Lynch, HSBC, Morgan Stanle, Nomura and India's JM Financial have been appointed to provide the broking services for the deal.