Cohort's subsidiary SEA has been contracted by BAE Systems to provide its External Communications System for the second stage of the common external communications system (cECS) for the UK Royal Navy.
Valued at £17m, the contract order will also cover further procurement and design activities.
Cohort chief executive Andrew Thomis said: "I am delighted that this important programme is continuing in line with our expectations.
"This substantial new order builds on the award in 2014 and we look forward to continuing our successful relationship with BAE Systems and the Royal Navy."
SEA's cECS is currently operational in the Royal Navy and is due to be incorporated into all operational and upcoming submarines.
The equipment is modularly designed and has a reconfigurable system, utilising open interfaces and standards.
It features an open architecture that facilitates a low cost upgrade and replacement of system elements.
cECS has an embedded network which enables an easy integration of legacy, current and future communications devices and reduces the burden of the operator and training requirement.
Under a previously awarded contract in 2009, SEA will provide the ECS for five new build Astute-class submarines.
In October 2014, SEA was awarded a further order to begin its design work on cECS, hence promoting the utilisation of ECS to all classes of Royal Navy submarines.
Further orders for Cohort's SEA are expected to be awarded next year.