CAMBRIDGE, MASS. -- The head of Japan's prestigious Science Council says his country is looking for someone to build a city on pillars in the Pacific Ocean for homes for up to 1 million people.

''It costs around $200 million,'' said Jiro Kondo, president of the council, which has completed a feasibility study of the project and hopes someone will build it in exchange for real estate rights.

There have been no firm offers, ''but {some} heavy industries are very much interested {and} some of the construction industry is also interested ... so there are no barriers'' to the program, he said.

Kondo declined to identify interested industries by name, but said, ''We are expecting to build the whole construction in 10 years.''

He spoke in an interview at the Massachusetts Institute of Technology, where he was attending a symposium recently called ''The Oceans in the 21st Century: Bringing Advanced Technology to the Ocean Industries.''

Others in attendance said Japan's search for more space gives it a valid reason for wanting to build such a project. It has 840 people per square mile; in contrast, California, roughly the same size, has 169 people for every square mile.

Because of that high population density, land in the central district of Tokyo costs $30,000 per square foot. While Japan's land area is only 3 percent that of the United States, its total land value is about $8 trillion, more than twice that of the United States.

''Japan is going to do this thing in one form or another,'' said John Craven, director of the Law of the Sea Institute at the University of Hawaii and a staunch proponent of the concept.

Kondo said planners tentatively are looking at sites 50 miles to 100 miles south of Tokyo, where the depth of the ocean is 430 to 495 feet.

The metropolis, dubbed Information City, would be supported by 10,000 pillars.

''Typhoons would not be a problem, because the huge waves can pass through easily,'' said Kondo. ''However, in the case of earthquakes, the pillars should absorb the shock, so shock absorption devices are introduced in these pillars.''

He said the project would have four layers, with a total area of 16 square miles. The top layer would be landscaped and have recreational facilities and an airport. Below that would be service and high-technology industry, followed by a residential layer and the bottom layer with utilities.

Planners do not anticipate problems in finding potential residents because of skyrocketing land prices and the great transportation problems commuters face now on the mainland, Kondo said.

''Many people are are looking for some nice place to live, and Information City puts where to live and where to work very close together,'' Kondo said. ''By means of an elevator, it takes only five minutes or 10 minutes to get to work and come home.''

Craven, who also has planned marine cities, said not to expect fast action on such a city.

The Japanese don't care ''that it's going to take 5, 10 or 15 years to do,'' he said. ''They just know that 20 years down the pike, they'll be in business, and the rest of the world won't.'