Honda Motor Co. said it plans to sell a nearly emission-free, natural gas-powered version of its new Civic sedan in all 50 states starting this year.

The company also plans to release a hybrid version of the 2012 Civic, which it debuted at the Detroit auto show. The Civic is set to go on sale later this spring.

The 2012 Civic is the ninth generation of the popular sedan, which first went on sale in 1972. It has a more sophisticated look than its predecessor, with chiseled lines in the sides and on the hood and a more aerodynamic roof.

Honda will offer two-door and four-door versions. It wouldn't reveal a price, but the current Civic starts at $15,805.

The last generation of the Civic, which went on sale in late 2005 as a 2006 model, has been a perennial best-seller in the U.S. But sales began to taper off as newer competitors like the redesigned Toyota Corolla came on the market. Honda Civic sales were flat last year compared to the year before.

The small-car segment is expected to heat up in 2011 as gas prices rise and more new models come on the market, including the Chevrolet Cruze, Ford Focus and Hyundai Elantra. John Mendel, executive vice president for sales for Honda in the U.S., said he welcomes the competition.

"It's a great time to be a consumer in the marketplace," Mendel said.

Mendel dismissed concerns about the pace of Honda's U.S. sales in 2010. Honda's sales were up 7 percent over 2009, but the overall industry's sales were up 11 percent. He said Honda's sales didn't dip as far as some other companies in 2009, and it relied less on sales to daily-rental and commercial fleets in 2010 than some of its competitors.

"If you're looking for long, consistent, continual growth, you have to look at Honda," he said.

Honda currently sells around 1,500 natural-gas Civics each year, mostly to government fleets. Until now, it only sold natural-gas Civics to individual buyers in California, Oklahoma, New York and Utah.

But the company wants to widen access to the vehicle, which has a traditional internal combustion engine but produces almost no emissions. Ninety-eight percent of natural gas used in the U.S. also comes from North America, which advocates say lessens dependence on foreign oil. There are around 1,000 natural gas fueling stations in the U.S., and 500 of them are open to the public, according to Natural Gas Vehicles for America, a lobbying group.

The traditional gas-powered Civic will get around 40 miles per gallon, according to Mendel.

For the hybrid version, Honda will use a lithium-ion battery for the first time. Previously, it used a nickel-metal hydride battery, similar to the one used in the Toyota Prius.