Warburg Pincus LLC, an American private equity firm has acquired a minority stake in Fusion Microfinance, a non-banking financial company (NBFC) for Rs.520 crore ($ 75 million). Creation Investment, an existing investor, has also participated in this round. Investors such as Belgium’s Incofin, NMI, BIO and SIDBI have made successful exits in this round. “This is…