Amazon.com is in early-stage talks to buy a stake worth at least $2 billion in Indian mobile operator Bharti Airtel, three sources with knowledge of the matter told Reuters, underscoring the growing attraction of India's digital economy for U.S. tech giants.

The planned investment, if completed, would mean Amazon acquiring a roughly 5% stake based on the current market value of Bharti, which is India's third-largest telecoms company with more than 300 million subscribers.

The discussions between Amazon and Bharti come at a time when global players are placing major bets on the digital arm of Reliance Industries, which owns Bharti's telecom rival Jio.

Reliance's digital unit has raised $10 billion in recent weeks from Facebook, KKR and others.

The talks between Bharti and Amazon are at an early stage and the deal terms could change, or an agreement may not be reached, said two of the three sources, all of whom declined to be identified because the discussions are confidential.

An Amazon spokeswoman said the company does "not offer comments on speculation of what we may or may not do in future."

Bharti said they routinely work with all digital players to bring their products, content and services to customers. "Beyond that there is no other activity to report," it said in a statement.

Amazon (AMZN) counts India as a crucial growth market where it has committed $6.5 billion in investments mainly toward expanding its e-commerce footprint.

The Seattle-based company has in recent years also expanded its digital offerings in India via its voice-activated speakers, video streaming and cloud storage, as it seeks to tap a rising number of internet and smartphone users in the country of 1.3 billion people.