His comments, earlier this week, offer a rare look into product development strategy at a major automaker. They also counter the common wisdom about the reason for the success of Toyota Motor Corp.'s gasoline-electric hybrid Prius, believed to have drawn buyers because it is a hybrid-only model.

Tokyo-based Nissan is a latecomer to hybrids compared to Japanese rival Toyota. It currently buys hybrid systems from Toyota for the Nissan Altima hybrid but is promising a vehicle packed with Nissan's own hybrid system by 2010.

'There may be no point in waving the hybrid flag at this point,' Yamashita told The Associated Press, referring to both Toyota's success and the anticipated proliferation of hybrids. 'Hybrids may not be all that special.'

Yamashita declined to disclose the models but suggested the his company's hybrid system may be offered in the Nissan Z. Nissan will offer a mid-size hybrid with a bigger engine than the compact Prius, he said.

Nissan showed a prototype hybrid earlier this week in the luxury Infiniti G35, called the Skyline in Japan.

Besides the Prius, Toyota offers hybrid versions of its gasoline-powered models, including Lexus luxury cars and Camry.

Not all hybrid-only models have been successes.

Honda Motor Co.'s Insight, a hybrid-only model, was discontinued in 2006 due to poor sales. Honda is introducing a new hybrid-only model next year.

Nissan showed its electric car prototype in a Cube compact. But Yamashita said reducing wind resistance is critical for an electric vehicle's efficiency, hinting the model in the works will have a futuristic aerodynamic design.

Nissan faces competition in electric vehicles. U.S. automaker General Motors Corp. is planning a Chevrolet Volt plug-in electric vehicle in 2010.

Hybrids reduce pollution as well as global warming emissions by switching between a gasoline engine and an electric motor. Their popularity is growing amid soaring oil prices. Electric vehicles, which are zero-emission, are also increasingly drawing attention.