Japan, Britain and Italy will next week sign a treaty in Tokyo to create a joint agency and industrial group to develop their planned advanced fighter jet, three sources with direct knowledge of the plans said.

An intergovernmental organization will oversee the project, led by the British BAE Systems PLCthe Japanese Mitsubishi Heavy Industries and the Italian one Leonardo. This group will divide work into groups in its various departments Global Combat Air Programme (GCAP), such as the plane’s engine and electronic systems, said the sources, who asked not to be identified because they were not authorized to speak to the media.

Reuters reported in March that Japan and Britain would dominate the GCAP, taking on about 40% of the project each. Rome dismissed it as speculation.

Japan’s defense ministry declined to comment. Officials at the British and Italian embassies did not immediately respond to requests for comment.

The deal, which must be ratified by the parliaments of each of the three countries, comes a year after their first major defense industry collaboration by merging London and Tokyo’s separate next-generation fighter jet efforts.

Someone from Japan may initially lead the program and its leadership will rotate between the three countries, two of the sources said. Japan’s leading candidate for the post is Masami Oka, a defense ministry adviser who retired in July as vice minister of international affairs, they added.

Oka did not immediately respond to a request for comment.

* Photo source Wikipedia