The deal values India’s biggest retailer at 4.2 trillion rupees ($57 billion), the New York private-equity firm and the Mumbai group said in statements.
"Reliance Retail Ventures is empowering merchants of all sizes and fundamentally changing the retail experience for Indian consumers," KKR Co-Founder and Co-CEO Henry Kravis said.
"Reliance Retail’s new commerce platform is filling an important need for both consumers and small businesses."
The retail unit aims "to become India’s leading omnichannel retailer and ultimately to build a more inclusive Indian retail economy," Kravis added.
Reliance Retail operates nearly 12,000 stores nationwide. The company is helping small and unorganized merchants by taking their business online and is committed to expanding the network to more than 20 million merchants.
This deal marks KKR's second investment in Reliance Industries, following a $1.5 billion investment in its digital-services arm, Reliance Jio, earlier this year.
The KKR-Reliance deal follows a $1 billion investment by Silver Lake Partners, the Menlo Park, Calif., tech-focused PE firm, in Reliance Retail. That deal was unveiled earlier this month.
Reliance Retail and Reliance Jio are controlled by Mukesh Ambani’s refining-to-telecom conglomerate, Reliance Industries Ltd.
"We look forward to working with KKR’s global platform, industry knowledge and operational expertise across our digital services and retail businesses," said Ambani, chairman and managing director of Reliance Industries.
Morgan Stanley is financial adviser to Reliance Retail and Deloitte Touche Tohmatsu India advised KKR on the latest deal.
Earllier this month Bloomberg had reported that Reliance Retail had expressed interest in negotiating a transaction with retail giant Amazon (AMZN) - Get Report to sell as much as a 40% stake in the Reliance subsidiary.