A total of 250 jobs have been protected by a £45m government contract for testing Royal Navy warship weapons systems.
QinetiQ and BAE Systems have been awarded the four-year shore-testing programme which is carried out at Portsmouth, Hampshire.
It involves specialised analysis of combat systems ahead of being fitted on the warships which include the new Type 45 destroyers and the next generation of aircraft carriers.
Peter Luff, minister for defence equipment, support and technology, said: "This is good news for both the Portsdown Technology Park, Portsmouth, which remains a strategic national asset, and for the local economy as 250 local jobs will be sustained.
"Portsdown is essential to ensuring that our sailors have the safe and highly effective equipment they need whilst on operations across the world.
"The collaboration of QinetiQ and BAE Systems will be fundamental and demonstrates how the MoD and industry are forging ahead together to support our armed forces."
Chief of Material (Fleet), Vice Admiral Andrew Matthews said: "The facility in Portsdown is a jewel in the MoD's crown as it provides our Royal Navy with a UK-based centre of excellence for the integration of maritime combat systems.
"It makes sure that our ships have all the right equipment working seamlessly, so our sailors can trust that their equipment will work correctly, first time and every time."
The news follows reports that BAE Systems is considering the closure of its Portsmouth shipbuilding base.
Mark Townley, combat systems director at BAE Systems, said: "We selected this facility as a centre for the Type 45 combat system integration and have further developed it for the mission system for the Queen Elizabeth class aircraft carriers.
"This latest contract underlines the region's position as the centre for combat systems capability in the UK and creates an opportunity to build on our success in maintaining and updating the Royal Navy's equipment against a backdrop of increasingly complex technology and rapid rates of development."