For hybrid car sales, the numbers are sobering. December’s sales of 17,697 hybrids were down 42.8 percent from the same month the year before. What’s interesting here, however, is that the three top-selling models are all made by Toyota, including the Prius and Camry hybrids and the Lexus RX-400h. The Highlander hybrid SUV is in seventh place.  Sounds good, right?

Actually, no. Toyota is planning to post the first full-year loss in its core auto business since 1937. At $5 billion, the deficit isn’t going to send the company to bankruptcy court. Toyota is relatively healthy compared to most other automakers. Toyota has never laid off its fulltime employees, and it hasn’t made any plans to do so now.

Toyota is also moving ahead with its green car plans. In a speech at the Washington Auto Show February 5, company spokesman Irv Miller said that the company is increasing its budget for advanced environmental technology (no dollar figures cited), and is moving up its introduction of plug-in hybrid cars to December of this year from “early 2010.”

The 500 initial plug-in cars will have lithium-ion batteries built by Toyota itself at a factory in Japan it shares with Panasonic. (The joint venture expects to be making a million nickel-metal-hydride battery packs a year by early 2010.) Some 150 of the plug-in cars will come to the U.S., to be leased to fleet customers.

Even with the red ink, Toyota’s Miller says the company will introduce 10 new hybrids in the next decade, and expects to be selling a million a year by the end of that period. It will have a fuel-cell car on the market in 2015, and a battery-powered one out there by 2012.

Toyota, with cars in almost every market segment, is better placed to ride out the downturn than most of its competitors. The Prius isn't dragging the company down: It's Toyota's third best-selling model, after the Camry and Corolla. Toyota sold more than 285,000 worldwide last year. The green direction is not only smart, but good business, too.

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.