Just a day after Yahoo China (YHOO) announced its new paid rankings search service, Baidu.com disclosed to reporters that the "Paid Rankings" system was originally created in China by Baidu and Yahoo has no right to offer the same service on the mainland.

Baidu is considering lodging a lawsuit against Yahoo China to protect its interests as the innovator in this sector.

Local reports say industry analysts believe Baidu's actions are a pre-emptive strike against Yahoo because Yahoo has implied that one of its affiliates plans to apply for a patent for a kind of search ranking service in the US. If that happens, all of Yahoo's competitors, including Baidu, might face legal problems, themselves.