DETROIT (Kyodo) Toyota Motor Corp. released the 2010 model of the Prius, the world's best-selling hybrid car, at an international auto show in Detroit on Monday.

The new model of the gasoline-electric vehicle, which will go on sale in more than 40 countries after its release in mid-May in Japan, is expected to compete with the 2009 Insight hybrid of Honda Motor Co., which will be launched in Japan in February and is also on display at the North American International Auto Show that opened Sunday.

"Today I have the privilege of showing you the third generation of the vehicle that symbolizes Toyota's fundamental commitment to preserving and improving the world in which we live," Toyota Division Group Vice President and General Manager Bob Carter told reporters minutes before the unveiling.

The new Prius has an engine displacement of 1,800cc, up from 1,500cc. But fuel-efficiency has been improved by about 9 percent due to the adoption of a ventilation system using electricity generated by solar power, Toyota said.

Toyota Vice President Masatami Takimoto said the new Prius will not be outdone by the Insight in fuel-efficiency.

"It would be welcome even if the Insight sold well. We want to see the Insight and the Prius compete against each other," he said.

The cumulative sales of the Prius since the debut of the first model in 1997 topped 1.2 million units at the end of last year.