The secondary share sale was executed at Rs 400.6 per share, representing 3.6 per cent discount to the previous day's closing price, Airtel said in a statement.
The buyers included global investors, fund managers and long-only funds, including many repeat investors, it said, adding that the deal was upsized by over 25 per cent given "healthy investor appetite".
"Bharti Airtel will primarily use the proceeds from this sale to reduce its debt," the statement added.
The consolidated debt of the Sunil Mittal-owned company was Rs 91,480 crore as on September 2017.
Like other incumbent operators, the country's largest telecom company has been locked in a fierce tariff war with newcomer Reliance Jio in the mobile telephony market.
After today's share sale, the stake of Bharti Airtel and its wholly-owned subsidiaries in Bharti Infratel would come down to 53.51 per cent.
According to BSE data, the promoters' holding in the tower infrastructure company stood at 58 per cent as on September 2017.
The sale was carried out by Airtel via its wholly-owned subsidiary, Nettle Infrastructure Investments.
Announcing the "successful divestment" of 83 million shares in Bharti Infratel, the company said: "The sale was for a total consideration of over Rs 3,325 crore (USD 510 million) and was executed at a price of Rs 400.6 per share, representing a discount of 3.6 per cent to the previous day's closing price."
JP Morgan, UBS and Goldman Sachs were joint placement agents for the transaction.
Telecom tower companies have been grabbing the headlines over the last few weeks.
Vodafone India and Idea Cellular, which are headed for a merger, said yesterday that they have separately decided to sell their tower businesses in India to ATC Telecom Infrastructure for Rs 7,850 crore.
Late last month, Bharti Airtel said that a few "reputed" global investors had approached it for buying a controlling stake in Bharti Infratel, which, in turn, had just announced that it will explore acquiring more stake in joint venture Indus Towers. Bharti Infratel and Vodafone India hold 42 per cent stake in Indus Towers and rest is held by Idea Cellular.
In the same breath, Airtel's board had also authorised the telecom firm to continue evaluating and selling shares in Bharti Infratel in one or more tranches from Airtel itself or its subsidiary Nettle.
Airtel had, earlier this year, sold 10.3 per cent stake in Bharti Infratel to a consortium of KKR and Canada Pension Plan Investment Board for Rs 6,193.9 crore.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)