Business executives proposed Thursday burying Tokyo's elevated and aging expressways 60 meters underground, thereby creating an eco-friendly urban environment and hundreds of thousands of jobs.

The proposal was submitted in writing to Finance Minister Kaoru Yosano by representatives of Tokyo's three local chapters of the Rotary Club. It was also presented to Tokyo Gov. Shintaro Ishihara earlier this week.

The proposal calls for the elevated sections of the Metropolitan Expressway network in the heart of Tokyo, officially called the Inner Circular Route, to be demolished and replaced by the new underground network.

The new system would stretch some 50 km, including the present 14.4-km elevated sections, and will cost about ¥4 trillion, which the group claims is economically viable as a private undertaking.

The megaproject will have ripple effects of up to ¥12 trillion, create 400,000 to 500,000 new jobs and dramatically reduce vehicle emissions, the group said.

It will use the new legislative framework for "deep underground" utilization for public works and will not count on state coffers to finance the project by introducing the private finance initiative method, it added.