The UK Ministry of Defence (MoD) has selected BAE Systems as the preferred bidder to deliver the gun system, called maritime indirect fires system (MIFS), for the UK Royal Navy's Type 26 Global Combat Ship (GCS).
The latest development follows the UK MoD £859m contract with BAE for the navy's Type 26 GCS programme in February this year.
Under the latest contract, the company will be responsible for delivering the MIFS integrated gunnery system (IGS).
IGS comprises the 5in, 62-calibre Mk 45 Mod 4 naval gun system, in addition to an automated ammunition handling system, gun fire control system, and qualified ammunition.
BAE Systems Weapon Systems vice-president and general manager Joe Senftle said: "The Mk 45 is at the centre of our MIFS solution and will provide the Royal Navy with a low-risk, low-cost, and highly effective automatic weapon system.
"It combines the benefits of a mature, reliable, and proven system with the capacity to deliver the full range of ammunition available today and in development."
Earlier this year, BAE and the US and Royal Navies conducted technical briefings on the Mk 45 gun aboard the USS Winston Churchill, offering Royal Navy members an opportunity to further experience the features and capabilities of the gun system.
The Mk 45 Mod 4 gun can hit a target with better accuracy up to 23 miles away, while with specially-adapted extended-range shells, it can hit objectives 57 miles away.
The gun will also able to deliver up to 20 standard shells a minute at more than twice the speed of sound.
Currently, the Mk 45 is in service with the US Navy and ten other allied nations. BAE Systems has delivered more than 240 Mk 45 guns so far.
The Type 26 multi-mission warships are being designed to conduct multinational missions, including complex combat operations, counter-piracy and humanitarian, and disaster relief work.
Construction of the first Type 26 GCS vessel is scheduled to begin in 2016 and will be commissioned after 2020. The Royal Navy is planning to build 13 ships, with an aim to replace the ageing Type 23 Duke-class ships.
Image: The 5in MK 45 Mod 4 aboard the guided-missile destroyer USS Forrest Sherman. Photo: courtesy of UK Royal Navy.