Mitsubishi Heavy Industries aims to take a technological leap with its plans to build an amphibious armoured vehicle that can move through water at 37 to 46 km per hour compared to the 13 km per hour speed of US marines' AAV7 assault vehicle.

In January, a top US Marine general visited Mitsubishi Heavy Industries in Japan to look at a prototype of an amphibious assault vehicle that could one day be a key pillar in Prime Minister Shinzo Abe's push to sell weapons abroad.

Using engines adapted from the main battle tank the company makes for Japan's military and new water jet propulsion technology, the full-size prototype is undergoing pool tests, although it is in the early stages of development and production could be years off.

Nevertheless, the maker of the wartime Zero fighter plane is eyeing overseas sales after Abe lifted a decades-old ban on arms exports in April last year as part of his more muscular security agenda, two Japanese defence industry sources said.

Mitsubishi designers believe the prototype shown to U.S. Marine Corps Pacific commander Lieutenant General John Toolan will be more maneuverable and faster across the water than the 40-year-old AAV7 amphibious assault vehicle used to carry U.S. marines onto beaches from naval ships anchored offshore, the sources said.

The AAV7 is built by the US unit of Britain's BAE Systems.

The prototype's engines in particular could be fitted onto other armoured vehicles, the sources added.

"It's an opportunity for Mitsubishi Heavy to tap overseas markets for its engine technology," said one of the sources, who declined to be identified because he was not authorised to speak to the media.

Mitsubishi Heavy wants to build an amphibious armoured vehicle that can move through water at 20 to 25 knots (37 to 46 km per hour) compared to the more than 7 knots (13 km per hour) reached by the AAV7, said the sources.

"If the Japanese can get 20 knots in the water without compromising maneuverability on land, we will be very interested," said one Marine Corps official who saw the prototype in January but declined to be identified.

"Whether that's possible remains to be seen."

A Mitsubishi Heavy spokesman said the prototype had been shown to the Japanese Ministry of Defense, but declined to give details about the vehicle. At a Paris arms show last June, a suitcase-sized model of an eight-wheeled armoured troop carrier was the centerpiece display at the company's exhibition booth.

The Ministry of Defense was aware of Mitsubishi Heavy's research into amphibious vehicles but was not involved in the project, a ministry spokesman said.

Manny Pacheco, a spokesman for US Marine Corps procurement, declined to comment on the prototype.

But he said the Marine Corps was "always interested in the technological advances of industry" and encouraged manufacturers to use "every opportunity to showcase their wares and get their products submitted through our competitive procurement process".-Reuters