Yahoo has reportedly filed a patent suit against Facebook, saying that the social network is infringing on technologies that are the “foundation of our business.”

It had been previously reported that Yahoo had demanded that Facebook pay licensing fees for at least 10 patents, and had threatened the IPO-bound social network with legal action if they could not come to a settlement. According to the court filing, the patents deal with technologies for advertising, privacy, social networking, messaging and allowing users to customize their Web experience.

In a statement, Yahoo said that it 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. These technologies are the foundation of our business that engages over 700 million monthly unique visitors and represent the spirit of innovation upon which Yahoo! is built. Unfortunately, the matter with Facebook remains unresolved, and we are compelled to seek redress in federal court. We are confident that we will prevail.”

In a statement, Facebook said, “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. Once again, we learned of Yahoo’s decision simultaneously with the media. We will defend ourselves vigorously against these puzzling actions.”

All Things Digital’s Kara Swisher, the first to report the news, had also previously reported that Yahoo’s new chief executive, Scott Thompson, is behind the push to sue Facebook over the disputed patents.

Thompson took over as CEO in January. Since his appointment, Yahoo’s board has seen a shake-up, with co-founder Jerry Yang and chairman Roy Bostock announcing that they will leave the company along with three other members of the board as part of an attempt to revitalize the company.

The case has been filed in federal court in San Jose, Calif., in the Northern District of California.

Many major tech companies have been filing lawsuits against one another in recent months. In fact, patent analyst and blogger Florian Mueller pointed out on Twitter that Yahoo’s lead counsel, Charels Verhoeven of Quinn Emanuel, and his team also represent Samsung and HTC in their patent cases against Apple as well as Motorola in its suits against Apple and Microsoft.

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