IBM has signed an extended deal estimated at up to $1 billion to manage the information technology systems of Vodafone's Indian unit until 2017, the Economic Times reported on Thursday.

Vodafone Essar had agreed a five-year IT outsourcing deal with IBM in 2007.

When contacted by Reuters, a Vodafone Essar spokesman said the companies had agreed to extend the deal, but declined to give any details. A spokeswoman for IBM in India could not immediately comment.

The newspaper cited three unnamed people as saying that the companies had agreed last month to restructure the contract estimated at $800 million to $1 billion.

The paper said the five-year contract signed in 2007 was worth more than $400 million.

For the newspaper story, see

(Writing by Devidutta Tripathy)