U.S. private-equity firm Kohlberg Kravis Roberts & Co is in talks to buy a controlling stake in Indian back-office service provider Firstsource Solutions, three sources with direct knowledge of the matter said. KKR is negotiating to buy a stake totalling about 68 percent of the IT services company from No. 2 Indian lender ICICI Bank, Singapore state investor Temasek Holdings and U.S.-based banking technology group Metavante, the sources said. A deal has not been finalised, but a sale price could be about $250 million, said two of the sources. None of the sources wished to be named as they were not authorised to speak to the media. Firstsource has a market value of $300 million. Private equity investment in India fell more than 60 percent in 2009 when the global financial crisis deepened, but a string of high-profile deals this year suggests a rebound. […]