L.A. Times:

It’s a patent war: Yahoo sues Facebook for infringement

Yahoo Inc., the onetime online advertising juggernaut dethroned by Facebook Inc., is suing the social networking giant over 10 patents that include ways to advertise on the Web.

The lawsuit filed in San Jose federal court Monday marks the first major patent battle in social networking. It comes as Facebook prepares to go public this spring in one of the most hotly anticipated stock market debuts in years.

In a statement, Yahoo said it is confident it will prevail.

“Yahoo has invested substantial resources in research and development through the years, which has resulted in numerous patented inventions of technology that other companies have licensed,” a spokesman said in an emailed statement. “Unfortunately, the matter with Facebook remains unresolved, and we are compelled to seek redress in federal court.”

A Facebook spokesman accused Yahoo of turning on a business ally and said it would vigorously defend itself.

“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,” the spokesman said in an emailed statement.