The US Navy has awarded GD Electric Boat an order to support engineering and design services for the its Ohio Replacement Programme.
The $8.8m order modifies an existing $76m contract signed in 2008 for engineering, technical services, concept studies and design of a common missile compartment for the next-generation of ballistic missile submarines.
The nation's next-generation strategic deterrent submarine is being developed for the Royal Navy and the US Navy.
The overall contract would have a value of more than $652m if all options are exercised and funded.
GD Electric Boat is a wholly owned subsidiary of GD.