The sale may raise as much as 300 million euros ($417.2 million), the people told the news agency.
Warburg Pincus officials declined to comment to the news agency.
UBS (UBSN.VX) is managing the sale, according to the report.
Warburg Pincus could not be immediately reached for comment by Reuters. ($1=.7190 Euro) (Reporting by Ajay Kamalakaran in Bangalore; Editing by Jon Loades-Carter)