SAN FRANCISCO - Yahoo Inc. sued Facebook Inc. over 10 patents that include methods and systems for advertising on the Web, opening the first major legal battle among big technology companies in social media.
The lawsuit, filed in a San Jose, California federal court on Monday, marks a major escalation of patent litigation that has already swept up the smartphone and tablet sectors and high-tech stalwarts such as Apple Inc, Microsoft Corp. and Motorola Mobility Holdings Inc.
Yahoo's patent lawsuit follows Facebook's announcement of plans for an initial public offering that could value the company at about $100 billion.
Facebook spokesman Jonathan Thaw said Facebook learned of the lawsuit through the media. "We're disappointed that Yahoo, a longtime business partner of Facebook and a company that has substantially benefited from its association with Facebook, has decided to resort to litigation," he said.