Toyota has come to the decision that petrol-electric hybrid technology has become a mainstream power source, and is planning to offer it as a standard option on most of its models by the end of the decade.

The company has announced that it will introduce one or two models a year until all of its high-volume trucks and cars can be purchased with either a conventional petrol engine or a hybrid equipped with a petrol engine combined with an electric motor.

The deployment is the first of its kind by a carmaker, and is expected to keep the company at the number one spot for American hybrid sales.

Other producers are likely to be stung into action by the roll out, which would introduce even more hybrids to the market over the next few years.

Toyota made the announcement at a briefing on the 2004 Prius hybrid, a new model of which went on sale today.

The Prius is only available as a hybrid, and has been bought by around 50,000 people since 2000.

Honda also markets a hybrid version of the Civic sedan, but is far behind its fellow Japanese rival in terms of US sales.