US private equity firm Silver Lake Partners will buy 1.75 per cent stake in billionaire Mukesh Ambani-run Reliance Industries Ltd's retail arm for Rs 7,500 crore and may be followed by KKR & Co. Silver Lake will invest Rs 7,500 crore in Reliance Retail Ventures Ltd, a subsidiary of Reliance Industries, for a 1.75 per cent stake, the Indian firm said in a statement. "This investment values RRVL at a pre-money equity value of Rs 4.21 lakh crore," it said.