Japan previously was building one 5,000-tonne class destroyer a year, but will now make two 3,000-tonne class ships a year, beginning from the April 2018 fiscal year, the people said, declining to be identified as they are not authorised to talk to the media.
It aims to produce a fleet of eight of the new class of smaller, cheaper vessels, which may also have mine-sweeping and anti-submarine capability.
Japan warship visits Philippines as China sea row festers
Naval shipyard operators including Mitsubishi Heavy Industries, Japan Marine United Corp (JMU) and Mitsui Engineering and Shipbuilding are expected to bid for the work, the people said.
Japan and China dispute ownership of a group of islands in the East China Sea, about 220 km (140 miles) northeast of Taiwan. In Japan, they are known as the Senkakus, while China calls them the Diaoyu islands.
Senior Japanese military officials have said they are concerned that China may seek to increase its influence in the East China Sea around Japan's southern Okinawa island chain. Japan provides military aid to South-east Asian countries including the Philippines and Vietnam that oppose China's territorial claims in the neighbouring South China Sea.
Build-sharing
In a departure from normal procurement practice, Japan's Ministry of Defence said in a report published on Wednesday it will require the winner of the - eight frigate - contract to offer major portions of the build to other bidders.
China launches new electronic intelligence naval ship
The change is meant to ensure naval shipyards remain open.
In the past two years, JMU has won contracts to build the larger Aegis-equipped destroyers, raising some concern among defence ministry officials that rivals could shutter their shipyards, one of the sources said.
"We need to ensure our ability to build naval vessels at home," the person said.
The new ships will cost 40-50 billion yen ($353-$443 million) each, another of the sources said.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ