Tata Consultancy Services buys Citigroup Global Services for 505 Million Dollar

Tata Consultancy Services informed the market that it has entered into a agreement with Citigroup for acquiring all of Citi’s stake in Citigroup Global Services,CGSL is india based BPO arm of Citi.This is for a cash dealing of 505 million dollar.First when i heard that they have bought the BPO arm of CITI for a half a billion i was thinking why would TCS do that , but now when i heard more info like there was also a deal made that TCS would process outsourcing services to Citi and its affiliates in an aggregate amount of US$ 2.5 billion over a period of 9.5 years. So this might be also extra reason behind buying into the BPO arm of CITI.