Xerox is suing Yahoo and Google for for alleged infringement of its patents on Internet search and e-commerce.

The 8 page complaint filed Friday in U.S. District Court in Delaware (PDF) says Google AdSense and AdWords, Yahoo's Contextual search software infringes its 2004 patent on a system for automatically generating queries. Xerox also alleges that Google Maps and YouTube, and Yahoo Shopping infringes its 2001 patent on Method and apparatus for the integration of information and knowledge.

Xerox spokesman Bill McKee told BusinessWeek, “We’ve been in dialogue with Google and Yahoo for some time without coming to a resolution. We believe we have no option but to file suit to properly protect our intellectual property.”

Google AdSense and AdWorks programs generates billions in revenue for Google. In Q4 2009 Google earned $2.04 billion, or 31% of total revenue from 3rd-party sites using the AdSense program.