Airtel will own an 18.3 per cent stake in Infratel after the transfer, down from its current stake of 50.33 per cent.
"Whenever Airtel transfers stake to Nettle Infrastructure, (eventually) they will sell the stake to a third party. This will help them raise money," said a Mumbai-based an analyst, who did not want to be named.
Airtel, like its peers in the industry, has faced immense competition since the entry of Reliance Industries' upstart Jio in late 2016 with its debts soaring and profit margins eroding.
Singapore Telecommunications Ltd said last week it will buy roughly $525 million worth Airtel stock as part of Airtel's plan to raise $4.6 billion through shares and bonds.
Nettle will buy Infratel shares for up to 362.45 rupees each, a premium of up to 13.4 per cent to the stock's closing price on Monday. Nettle already owns a 3.18 per cent stake in Infratel.
Bharti Infratel shares fell as much as 3.4 per cent to 309 rupees.