We previously reported that Yahoo was considering suing Facebook (News - Alert) after alleging that the company copied a range of technologies that Yahoo invented. A couple of weeks ago, Yahoo was in discussions with Facebook to try and sort out this patent issue; however now Yahoo has officially filed a lawsuit.

In a statement, Yahoo defends its reasoning behind the lawsuit. “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.  These technologies are the foundation of our business that engages over 700 million monthly unique visitors and represents the spirit of innovation upon which Yahoo Is built,” said the company. “Unfortunately the matter with Facebook remains unresolved and we are compelled to seek redress in federal court. We are confident that we will prevail.”

The suit describes several Facebook features that allegedly used Yahoo’s technology, such as Facebook’s News Feed, the primary way of viewing friends’ activity, and other privacy technologies that the company has continually upgraded over time. Yahoo continued to defend the patents, saying that even the format of Facebook’s Ad are the same as that of Yahoo’s.

Facebook made a statement in response to the allegations and now the lawsuit saying, “We’re disappointed that Yahoo’s effort to engage with us was limited to a few short phone calls…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,” said Facebook.

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

At this point in the process, Yahoo is demanding more than just a payment of the royalties on the patents Facebook has been using. “Yahoo is harmed by Facebook’s use of Yahoo’s patented technologies in a way that cannot be compensated for by payment of royalty alone,” said Yahoo. It looks like the company is looking for a settlement on the patents, along with a market share or continual revenue from Facebook for the patents.

Regardless of the suit, both companies at this point have stood their ground. Yahoo is continuing to claim that Facebook infringed on its patents, while Facebook strongly denies it did anything wrong. Now, it looks like the courts will soon have to decide the fate of the 10 patents in question.