Nokia has filed a number of lawsuits against Apple for violating 32 technology patents, striking back at the iPhone maker's legal action targeting the one-time cellphone industry leader a day earlier.
Nokia's lawsuits, filed in courts in Dusseldorf, Mannheim and Munich, Germany, and the US District Court for the Eastern District of Texas, cover patents for displays, user interfaces, software, antennas, chipsets and video coding.
"Since agreeing a license covering some patents from the Nokia Technologies portfolio in 2011, Apple has declined subsequent offers made by Nokia to license other of its patented inventions which are used by many of Apple's products," Nokia said in a statement.
Apple on Tuesday had taken legal action against Acacia Research and Conversant Intellectual Property Management, accusing them of colluding with Nokia to extract and extort exorbitant revenues unfairly from Apple.
Apple, Acacia, and Conversant did not immediately respond to requests for comment, and Nokia was not immediately available to comment on the Apple lawsuit.
The legal action by Nokia and Apple appears to mark a revival of the "smartphone patent wars" that began five years ago, when Apple filed a series of patent infringement cases against Samsung around the world, with wins and losses on both sides.
Apple's lawsuit against Acacia, Conversant, and Nokia was filed only one day after Conversant named Boris Teksler as its new chief executive. He had worked as Apple's director of patent licensing and strategy from 2009 to 2013, the latter half of his tenure overlapping with the lawsuits against Samsung.
Acacia is a publicly traded patent licensing firm based in Newport Beach, California. One of its subsidiaries sued Apple for patent infringement and was awarded US$22 million by a Texas jury in September.
Similarly, Conversant, which claims to own thousands of patents, announced last week that a Silicon Valley jury had awarded one of its units a US$7.3 million settlement in an infringement case against Apple involving two smartphone patents.
Nokia, once the world's dominant cellphone maker, missed out on the transition to smartphones triggered by Apple's introduction of the iPhone in 2007.
The Finnish company sold its handset business to Microsoft two years ago, leaving it with its telecom network equipment business and a bulging portfolio of mobile equipment patents.
But this year, Microsoft sold its Nokia feature phone business to a new company called HMD Global.
Nokia agreed to a 10-year licensing deal with HMD, which continues to market low-cost Nokia phones and plans to introduce new Nokia smartphone models next year.