American Tower Corp
American Tower would buy a 51% stake in Viom, which owns and operates about 42,000 mobile phone masts, from the existing shareholders, one of the sources said.
Newspaper reports, which first carried news of the deal, said the transaction could be worth as much as Rs 20,000 crore ($3.1 billion), including debt.
Viom is majority owned by mobile phone carrier Tata Teleservices Ltd, with Kolkata-based SREI Group holding about 18%. Viom's other shareholders are Singapore state investor GIC, Macquarie SBI Infrastructure Fund, Oman Investment Fund and India's IDFC Private Equity.
American Tower and Tata Teleservices did not immediately reply to emails seeking comment.
($1 = 65.1200 rupees)