Hybrid vehicles are expected to peak at around three per cent of the total US market by 2010, according to a new study by JD Power.

Around 88,000 hybrids were sold in the United States in 2004, accounting for about 0.5 per cent of total vehicle sales.

This year, the number of hybrid models is expected to increase from eight to 11, with sales expected to grow to 200,000, or about 1.2 percent of the market.

JD Power has predicted that the total number of models will expand to 38 by 2011, comprising 17 cars and 21 trucks and sport utility vehicles.

However it believes sales will plateau that year at about 535,000, or roughly three per cent of the US market.

"This is related primarily to the price premium of $3,000 to $4,000 consumers must pay for a hybrid vehicle, compared with a comparable non-hybrid," said Anthony Pratt, senior manager of global powertrain forecasting at JD Power.

The report does not necessarily signal bad news for the green auto industry. Automakers have said that gas-electric engines are largely a transitional technology that will eventually be replaced by hydrogen-powered fuel cells.