NEW DELHI- Indian oil-to-telecoms conglomerate Reliance Industries said on Sunday that the Abu Dhabi Investment Authority (ADIA) will buy 1.16% of its digital unit Jio Platforms for 56.83 billion rupees ($752 million).

ADIA's investment in Jio Platforms, which comprises Reliance's telecoms arm Jio Infocomm and its music and video streaming apps, gives the unit an enterprise value of 5.16 trillion rupees, Reliance said in a regulatory filing.

Reliance, controlled by India's richest man Mukesh Ambani, has now sold just over 21% of Jio Platforms to investors including Facebook Inc , securing nearly $13 billion in less than seven weeks.

On Friday, Abu Dhabi's state fund Mubadala Investment Co announced it would purchase a 1.85% stake in Jio Platforms for 90.93 billion rupees. 

"The rapid growth of the (Jio) business, which has established itself as a market leader in just four years, has been built on a strong track record of strategic execution," Hamad Shahwan Aldhaheri, executive director in ADIA's private equities department, said in a statement.

With estimated assets of nearly $700 billion, ADIA is chaired by the president of the United Arab Emirates, Sheikh Khalifa bin Zayed al-Nahyan, while its deputy chairman is Abu Dhabi Crown Prince Sheikh Mohammed bin Zayed al-Nahyan.

With more than 376 million users, Jio Infocomm is India's biggest telecoms firm by subscribers. Since entering the market in 2016 with free voice service and cut-price data it has forced out several rivals and driven consolidation in the sector.

Ambani has always pitched Jio as a tech company instead of a traditional mobile carrier, often saying publicly that "data is the new oil".

($1 = 75.5580 Indian rupees)

(Reporting by Sankalp Phartiyal; Editing by Jason Neely and Catherine Evans) ((sankalp.phartiyal@thomsonreuters.com; +91-11-49548064;))