New York - Apple is suing cell phone maker Nokia for patent infringement, a countermove to Nokia's earlier suit against technologies used in Apple's iPhone.
Apple's lawsuit claims Nokia is infringing on 13 of Apple's patents, and says the Finland-based company chose to "copy the iPhone," especially its user interface, to make up for its declining share of the high-end phone market.
Nokia's lawsuit, filed in October, claims that Cupertino, California-based Apple infringes on 10 of its patents covering both phone calls and Wi-Fi access.
The patents Apple alleges Nokia is infringing deal with, among other things: connecting a phone to a computer, teleconferencing, menus on a touch screen, power conservation in chips, and "pattern and color abstraction in a graphical user interface." The company also denies Nokia's claims of patent infringement.
In a statement, Nokia said it will review the claims and respond "in due course".
Apple said Nokia fell behind in the smart phone market because it chose to focus on old-fashioned cell phones with conventional user interfaces at a time when "smart" phones were growing increasingly popular.
Countersuits are a staple of patent litigation, which often ends in cross-licensing agreements. Nokia said in October that 40 phone manufacturers - but not Apple - have licensed the patents in its lawsuit.
Both suits were filed in federal court in Delaware.