The Prius, the world's first mass-produced gasoline-electric hybrid car, first went on sale in Japan in late 1997 and in other markets in 2000, and its cumulative sales have topped 1 million units worldwide.

The paper said Toyota would equip solar panels on the roof of the high-end version of the Prius.

If it happens, Toyota would be the first major carmaker to use a solar power generation system on a mass-produced vehicle.

The solar panels are made by Kyocera Corp.