America Online and General Motors announced June 13 that they are extending a marketing and advertising alliance to push for the sale of the auto giant's cars on the Internet.

As part of the multimillion dollar agreement, the companies will continue to promote GM's full line of cars and trucks across AOL and its other interactive brands, including Netscape.com, CompuServe and Digital City.

AOL and GM also said they will continue to co-promote the GMBuyPower.com Web site, which enables consumers to locate an automobile in a dealer's inventory, access finance tools, view special Internet-only offers and e-mail dealers for price quotes.

GM said the companies originally formed an alliance in January 2000, but declined to specify the duration of the new agreement. According to published reports, the June 13 deal allows them to extend the relationship through January 2002.

During the past year, nearly 400,000 AOL subscribers signed up for GM sweepstakes or requested brochures on the automaker's products, the companies said.

Although some recent studies have found that automakers need to focus their online efforts on building brand awareness, rather than generating new car sales, a report released last month by Jupiter Media Metrix also concluded that portals -- such as AOL -- are the single largest source of traffic for automaker and third-party sites.

Jupiter said that automaker sites receive 36 percent of their traffic from portals, and third-party sites garner 47 percent of their traffic from them, which could bode well for the AOL-GM deal.

GM has been expanding its presence in the online automotive market with several deals. In February, it signed a deal with Autobytel.com to test an online shopping system that will show consumers which cars are available for purchase in their area.

GM said the trial run, which began in May and is slated to run for 90 days, will provide the company and its dealers with a framework for creating an online locate-to-order system. The cars shown to consumers will bear dealer-set Web prices.

During the same month, the giant automaker also said it would form a partnership with its network of dealers to build a Web shopping site called AutoCentric, which will offer GM cars as well as other brands.

GM also has a marketing alliance with eBay Motors.