UPDATE 1-Transocean rig wins $535,000/day contract

(Recasts first paragraph, adds background, share price, day rate)

HOUSTON, Feb 19 (Reuters) - Transocean Inc (RIG.N: Quote, Profile, Research), the world's largest offshore drilling contractor, said on Tuesday one of its deepwater Gulf of Mexico drill ships has been awarded a 3-year extension at a rate 20 percent higher than the old pact.

Anadarko Petroleum Corp (APC.N: Quote, Profile, Research) has renewed its contract for the Transocean's Deepwater Millennium for $535,000 per day, up from $447,000, Transocean said.

Tight supplies of offshore drilling rigs coupled with booming demand have driven dayrates up.

The estimated revenue which could be generated over the life of the contract extension is about $586 million, Transocean said.

The contract is expected to start in June 2010.

Shares of Transocean rose 1.4 percent to $131.48 after the close of regular trading. (Reporting by Anna Driver in Houston; Editing by Tim Dobbyn)