Toyota has announced that global sales of its hybrid vehicles, which include the Prius and two hybrid SUVs, reached 513,000 units by the end of October. The hybrid design, which combines a conventional gasoline engine with a battery-powered electric motor to maximize fuel economy, first appeared in the company's Prius model in 1997 in Japan. In 2000, it was offered in Europe and North America. Last month, the company said growing use of hybrid vehicles has already saved more than 100 millions of gasoline. It also announced intentions to halve the cost of its hybrid powertrains as soon as possible.