Lodsys, a Texas patent licensing company, alleges Rovio and other developers violated its patents with games on Apple's iOS platform and Google's Android, the BBC reported Friday.
Lodsys has filed lawsuits against other big technology companies, including Apple.
It filed an amended complaint with the U.S. District Court for the Eastern District of Texas, naming a number of other big games makers including Atari, EA, and Take-Two Interactive, The Wall Street Journal reported.
Rovio's Angry Birds is available for both Apple's iOS and Google's Android's platform.
The company said Angry Birds has been downloaded more than 300 million times.