Toyota will start mass-producing a plug-in version of its Prius hybrid in 2012, with plans to make 20,000 to 30,000 of the vehicles that year, according to news reports.

The Japanese newspaper Nikkei reported the news Saturday, according to Reuters. Toyota had previously said that it intends to bring about 500 of the new plug-in version of its best-selling hybrid to fleet customers by the end of this year (see Toyota's Plug-In Prius Heads to France).

Reuters reported that Toyota plans to sell its new plug-in Prius at a price close to that of Mitsubishi's promised all-electric car, which will be sold to fleet customers in Japan this month for about 4.59 million yen ($47,800). That's without government subsidies of roughly $15,000 in Japan, which would lower the cost to buyers to about $30,000 (see Green Light post).

The new plug-in Prius will be powered by lithium-ion batteries developed and built in a joint venture with Panasonic EV Energy Co. That's a departure from the nickel metal hydride batteries in the gasoline-electric Prius hybrids on the road today.

The plug-in Prius will be able to go about 12 to 18 miles on battery power alone before its gasoline-powered engine kicks in, according to Reuters.

General Motors plans to have its plug-in hybrid Chevy Volt on sale late next year. Ford said it plans to be building plug-in hybrid vehicles by 2012, though it will precede those with an all-electric commercial van in 2010 and an all-electric passenger car in 2011.

Toyota also plans to have a battery-powered compact car called the FT-EV on the market by 2012.