Motorola is asking a court to invalidate 12 Apple patents, even though Apple hasn't accused Motorola of infringing them.
It's the latest move in an increasingly contentious battle over smartphone dominance and one that often puts Android in the crosshairs.
In Motorola's filing with the US District Court for the District of Delaware, the company says that Apple has a history of asserting the patents against Android, citing HTC as one example of an Apple target.
"As a result... Motorola Mobility has a reasonable apprehension that it faces an infringement suit related to the patents-in-suit," Motorola wrote in the filing.
Motorola says that it had engaged in confidential negotiations with Apple over licensing intellectual property. For each of the named patents, Motorola says that Apple claims rights over certain Motorola phones. However, Motorola denies infringing the patents, claiming that the patents aren't valid.
The suit was filed earlier this month, just days after Motorola sued Apple in the U.S. District Court for the Northern District of Illinois and the Southern District of Florida and filed a complaint with the U.S. International Trade Commission. In those complaints, Motorola said that it had engaged in lengthy negotiations over Motorola patents with Apple but that Apple had refused to buy licenses.
The Motorola suit joins a long list of other recent legal activities in the smart phone industry, many of which target Android. HTC, one of the biggest producers of Android phones, and Apple have sued each other, charging patent infringement. Microsoft recently sued Motorola over its Android phones. In addition, Oracle sued Google over the way Android handles Java.
The suits highlight the threat Android poses in the market. In the second quarter this year, Android overtook both Research In Motion and Apple in the U.S., becoming the number one smartphone operating system in the region, according to Gartner. It became the third most popular smart phone OS in the world, behind number one Symbian and RIM, Gartner found.