The decision comes several months after Japan lifted a self-imposed ban on weapons exports, as Prime Minister Shinzo Abe looks to expand Japan's diplomatic and military presence on the global stage.
The exports would be the first since Japan in April approved a new policy that replaces its 1967 blanket ban on shipping arms overseas.
The joint research with Britain was linked to a European missile project called Meteor, with an initial emphasis on how current Japanese technology could enhance British-developed missiles, according to a statement jointly issued by several ministries, including Japan's foreign and defence ministries.
"We believe that we can create more sophisticated products by bringing together the finest technologies from both Britain and Japan," a Japanese defence official told a press briefing today evening.
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In a separate decision, Tokyo would also allow US-bound exports of parts for the Patriot Advanced Capability-2 (PAC-2) missile defence system developed by Washington.
The parts were originally supplied by a US defence contractor that no longer makes the product.
An earlier report this month by the leading Nikkei business daily said Mitsubishi Heavy Industries plans to export a high-performance sensor for the PAC-2 missile defence system.
Under Japan's new arms export rules, weapon sales are still banned to conflict-plagued countries or nations that could undermine international peace and security, and they must contribute to international peace and boost pacifist Japan's security.