The Houston company's ultra-deepwater drillship Dhirubhai Deepwater KG2 is owned by a 50-50 joint venture with Washington-based Pacific Drilling Ltd.
Estimated revenue from the contract is $90 million over the first six months and $838 million for the remaining 54 months.
Transocean (NYSE: RIG) expects to begin the contract in early 2010 following shipyard construction, mobilization to India and customer acceptance.
Separately, India-based Reliance extended its contract by one year with Dhirubhai Deepwater KG1, Transocean's other joint venture drillship with Pacific Drilling.
Both vessels are currently under construction at Samsung Heavy Industries' shipyard in South Korea.