The US Department of Defense has placed a further order for 87 M777A2 155mm towed howitzers with BAE Systems.
The US$176m order is an extension of a previous order for 589 howitzers.
The M777 howitzer is the world's first artillery system to incorporate large-scale use of titanium and aluminium alloys, BAE says.
The world's lightest 155mm howitzer, it weighs less than 4,220kg – under half the weight of a conventional 155mm system.
The gun uses M982 Excalibur guided ammunition, developed by Raytheon and BAE Systems, with a maximum range of 40km with an accuracy of up to 10m.
The latest order will be delivered in 2010, BAE says.
By Elizabeth Clifford-Marsh