SeaDrill Ltd., a Norwegian oil-rig maker, said it won a contract to supply a drilling rig for use in the Gulf of Mexico.

The so-called semi-submersible rig, West Sirius, is under construction in Singapore and will be delivered by June 2008, the Bermuda-based SeaDrill said yesterdayday in a statement to the Oslo Stock Exchange.

The value of the contract may rise to $980 million over a six-year period, the company said. SeaDrill didn't identify the company that ordered the rig.