General Motors, Chrysler LLC and Lexus Division are using a new feature of the online auction eBay to promote their dealers' certified used vehicles.

The eBay Motors Certified Pre-Owned Showroom launched this month. It lists more than 70,000 factory-certified used cars and trucks for sale by more than 5,000 dealerships, said Rob Chesney, eBay Motors vice president.

The listings are free to dealers. The company says eBay Motors attracts 12 million unique visitors each month.

Certified sales are "holding up pretty well in this economy," Chesney told Automotive News. "We thought it was important to aggregate as much of that inventory as we could and bring it to our buyers."

The new site offers dealers templates to post vehicle data and photos. The site links to eBay Motors' home page, www.ebaymotors.com.

Lexus is the site's sole advertising sponsor. Matt Kaleba, Lexus' national certified pre-owned manager, says the luxury brand's dealers will list 5,000 to 6,000 certified vehicles on the site at any time.

"We thought it would be a great opportunity for us to educate consumers about our certified pre-owned program and give dealers more visibility for their inventory," Kaleba says of the eBay site.

Mark Mathews, General Motors' director of used-vehicle activities, says he expects GM dealers to list about 60,000 certified vehicles at a time on the site. Sharing the site with other automakers will draw a bigger audience, he predicts.

"It will naturally draw Internet customers," Mathews says. "People like to go to one place to one-stop shop."

Lisa Way, Chrysler's senior manager of certified pre-owned vehicles, says the company's dealers offer about 15,000 certified vehicles on the site. "To be successful in today's efficient used-car market, you've got to put your vehicles online," Way says.

Last month, the industry sold 163,553 certified vehicles, a 5.1 percent increase from May 2007. From January through May 2008, the industry sold 740,631 certified cars and trucks, a 4.4 percent increase over the year-ago period.