Toyota, the world's biggest automaker, has dominated the gasoline-electric hybrid market since putting the first Prius on the road in 1997. Toyota has 14 hybrid models globally, helping it win a reputation as one of the most advanced car makers in next-generation technology.

While rival Nissan Motor Co. and General Motors Co. look to share the green limelight with Toyota with their Leaf and Volt electric cars, launched last month, sales volumes are expected to stay at a fraction of the Prius until the high price of batteries comes down significantly.

Sales of Toyota's Prius sedan soared 36 percent last year to 140,928 units, according to Autodata, making it the most popular hybrid car on the road by far.

"Prius has become to hybrids what Kleenex is to tissues and Levi's are to jeans," Bob Carter, the Toyota brand's U.S. chief, said at the unveiling.

One of the two models unveiled at the Detroit auto show, the Prius V, will target families looking for more cargo space and utility compared with the current Prius hatchback, and will have estimated mileage of 40 combined for city and highway driving, Toyota said.

The car is due to hit U.S. showrooms this summer, Carter said.

Toyota also took the wraps off the Prius C Concept, which it called a city-friendly car aimed at young singles and couples who want a high mileage and fun-to-dirve Prius with a roomy interior.

"It will be the most value-oriented hybrid, with the highest mileage of any 'plug-less' hybrid available in the U.S.," Carter said, indicating that its mileage would exceed the conventional Prius' combined 50 mpg.

A production model based on the Prius C Concept will go on sale in the United States in the latter half of 2012.

The Prius V and Prius C Concept were showcased along with the current Prius and a plug-in hybrid (PHV) version of the car that Toyota plans to begin selling to individuals next year.

Toyota has a goal of selling at least 1 million hybrid vehicles annually worldwide before the middle of the decade, eventually offering a hybrid version on all of its models by 2020.

Toyota has plans to sell at least 50,000 units of the Prius PHV a year worldwide, mainly in Japan, the United States and Europe.

With more than $30 billion of cash and securities in its war chest, Toyota is among the few car manufacturers that can afford to develop vehicles across the range of technologies, including the batteries that power pure electric cars.

Toyota is also planning to launch two pure electric cars next year in the United States: an electric RAV4 crossover developed with U.S. startup Tesla Motors and a tiny, urban commuter model based on its own technology.