courtesy Seadrill

Seadrill has entered into a $598-million turnkey contract to build a third ultra-deepwater drillship at the Samsung Shipyard in South Korea, the drilling contractor announced Thursday.

Delivery of the deepwater unit in June 2010 means the Samsung-designed rig will enter the market after most of the world’s “new-build” drilling platform’s do in 2009. The drill ship is similar to two units Seadrill already has under construction at the Samsung shipyard.

The drill ship is the tenth deepwater unit Seadrill and its subsidiaries have ordered since the company was formed in May 2005, a statement said. Some $7 billion in drillilng units is reportedly under construction for Seadrill.