Texas-based ATP Oil & Gas Corporation has amended its agreement with Cosco Nantong Shipyard to defer $99m in construction costs for the Octabuoy hull, a floating oil production and drilling facility.

The vessel, topsides and related equipment will serve as the floating production and drilling facility at ATP’s Cheviot field in the North Sea.

According to a statement, the deferral will be supported by a letter of insurance issued by the China Export and Credit Insurance Corporation to the benefit of COSCO.

ATP president Leland E Tate said the transaction with SINOSURE and Cosco advances construction of the Octabuoy hull on pace for a 2011 delivery, and facilitates ATP’s objective to achieve first oil at Cheviot in 2012.

The hull provides improved motion characteristics when compared to conventional semi-submersibles. The Octabuoy will also be readily relocatable to other fields around the world after it has fully produced the Cheviot reserves.