Greece-based marine transportation service provider DryShips has revealed that its subsidiary Ocean Rig has launched a private placement of shares at $17.5 a share, for total gross proceeds of $500m.

Ocean Rig plans to use the net proceeds from the offering to finance the construction of ultra deepwater drillships under construction at SAMSUNG .

The offering is expected to close on 20 December 2010.

Following the transaction, DryShips will own a 78% stake in OceanRig.