The latest deal took the total new orders of Keppel Offshore & Marine, 100 percent owned by Keppel Corp, for the year-to-date to S$7.4 billion ($6 billion).

The rig, which will be delivered in the third quarter of 2013, will be able to operate in water depths of 350 feet (107 metres), drilling depth of 30,000 feet and accommodating 150 people.

Keppel said the exercise of the option is not expected to have material impact on its net tangible assets or earnings per share for the current financial year that ends in December.

COPYRIGHT REUTERS, 2011