Both TPG and its current promoter Krishna Kanumuri may sell stakes as part of the transaction. : Mumbai: Global private equity funds, including Bain Capital, KKR, and Advent International, are in talks for a controlling stake in Sai Life Sciences at a valuation of $600-700 million, three people aware of the development said. Sai Life Sciences (SLS) is a Hyderabad-based pharmaceutical contract research and development, and manufacturing (CRDMO) firm.