Sealift has been awarded a containership charter contract for up to five years with the transport arm of the US Navy.
The deal with the Military Sealift Command (MSC) involves the 3,740-teu Cap Spencer (built 2001), according to labour union American Maritime Officers (AMO).
The charter deal involves one firm year and options for four more.
Sealift, a Long Island-based company, is upgrading the ship and will transfer it to the US flag for the work.