Toyota Motor Corp. is planning to advertise on its Web site cars manufactured by General Motors Corp. of the United States and motorcycles made by Yamaha Motor Co., company sources said Thursday.

The leading Japanese automaker is in the final stages of negotiations with GM and Yamaha Motor on the marketing alliance, the sources said.

Toyota Motor will advertise products on its Japanese-language Web site Gazoo, which it is now upgrading.

GM and Yamaha Motor hope the strategy will lead to increased sales.

GM first asked Toyota to advertise its motor vehicles on the Web site in February.

Toyota does not directly sell its vehicles through the Gazoo site, but supplies shopping information and other data, such as on local Toyota sales agents.

Toyota set up the site in 1998. About 500,000 people have registered at the site, and Toyota hopes to raise the number to four million by 2003.

Toyota plans to negotiate with GM and Yamaha Motor on setting up by the end of this year a new site similar to Gazoo targeting the North American market.

Toyota and GM have formed a wide-ranging business alliance, including cooperation in developing hybrid electric-gasoline powered cars and fuel cells.

Toyota and Yamaha Motor agreed this month on a capital tieup. They have also agreed to strengthen cooperation in the development and production of automobile engines, the motor sports business and the marine business.