document: Lodsys has said that Rovio and other developers violated its patents with games on Apple's iOS platform and Google's Android.
  Lodsys is embroiled in lawsuits with other big technology companies, including Apple.
  Rovio said it had not received any direct contact regarding the complaint.
  "As soon as we receive more information we will take appropriate action," a spokesperson said.
  Angry Birds is one of the most popular game applications.
  Rovio marketing chief Peter Vesterbacka said last week that the game had surpassed 300 million downloads.
  Lodsys, a company that licenses patents but does not have any other business, added five new defendants to a suit filed in May with a US district court in Texas.
  Along with Rovio, it named Electronic Arts, Take-Two Interactive which makes Grand Theft Auto, Atari and others in the list of companies it says are violating its patents.
  Take-Two declined to comment. Electronic Arts and Atari were not immediately available for comment.
summary: Rovio, the Finnish maker of the Angry Birds game, is being sued by a licensing company for infringing its patents.