Citigroup Inc. is on the verge of selling its Indian business-process outsourcing unit to Tata Consultancy Services for $500 million to $550 million, The Economic Times reported Tuesday.

The deal for the Citigroup Global Services unit, which provides transaction processing and call center operations, is likely to be announced within three weeks, the Mumbai newspaper said, citing an unnamed source.

The Economic Times reported that Citi, which is raising capital to deal with the credit crisis, is also said to be interested in selling Citos, its Indian technology and infrastructure outsourcing unit.

Citi, of New York, has reached deals to sell several other units in recent months. Last month it said it had agreed to sell its German retail banking operations for $7.75 billion.

Also last month, Citi shut down its Old Lane Partners LP hedge fund and significantly pared back its Japan operations by shutting 32 branches and 540 automated loan machines. In April it agreed to sell most of its small- and middle-market commercial finance business, CitiCapital. In May, Citi and State Street Corp. agreed to sell their joint venture, CitiStreet LLC.

A Citi spokeswoman declined to comment Tuesday. Tata, the information technology arm of Tata Group of Mumbai, did not respond to a request for comment.