India-based CGS is the business process outsourcing (BPO) arm of bank Citi. In addition to the sale, Citi has signed an agreement for TCS to provide, through CGS, process outsourcing services to Citi and its affiliates in a deal worth almost £1.5bn over 9.5 years.
The agreement builds upon the existing relationship between Citi and TCS, whereby TCS provides application development, infrastructure support, help desk and other process outsourcing services to Citi.
The acquisition broadens TCS's portfolio of end-to-end IT and BPO services in the global banking and financial services sector.
CGS has more than 12,000 employees located in India and expects to generate revenues of around £165m in 2008.
The deal is expected to be completed in the fourth quarter.