The contract will also include an option for a 10th boat if needed, sources said.
The news, which was first reported by Bloomberg, is the latest jolt to the Virginia-class program that has seen creeping delays and slipping profits in recent years caused by labor issues and a strained submarine industrial supply base. The contract was originally intended to be signed by October of last year, at the start of the 2019 fiscal year, according to Navy budget documents.