Private equity group Providence Equity Partners said Thursday that is has invested $640m in a subsidiary of Indian mobile operator Idea Cellular.

The investment is on Aditya Birla Telecom Limited (ABTL) and will get providence a 16 per cent stake in Indus Towers, a joint venture formed by Vodafone Essar, Bharti Airtel and Idea to provide infrastructure services to mobile operators in 16 telecom service areas.

This is believed to be one of the largest private equity investments in India, and Aditya will use the cash to fund its network rollout and ongoing operations.

The Bihar service area, which ABTL operates in, covers the states of Bihar and Jharkand and has the second highest population among all service areas of India, but the lowest mobile penetration.