HTC sued Apple claiming infringement of three patents through Apple's sale of Macintosh computers, iPads, iPods, iPhones and other devices. The lawsuit filed in U.S. District Court in Delaware seeks to halt Apple's importation and sale of infringing products in the United States. It also seeks compensatory damages, triple damages for willful infringement and other remedies.

Tuesday's complaint escalates the legal battle between the companies. Apple has accused HTC of patent infringement through its smartphones, and filed several patent lawsuits against the Taiwan-based company in Delaware in the last two years.

HTC filed its lawsuit one day after Google Inc agreed to pay $12.5 billion in cash for Motorola Mobility Holdings Inc to gain access to thousands of patents and help protect its fast-growing Android mobile operating system.

That merger, if completed, could put pressure on HTC and other Android licensees, which face the risk of promoting a direct rival. Google last year developed the Nexus phone with HTC, but sales proved disappointing.

According to its complaint, HTC obtained the patents that it believes Apple is infringing in 2008 and 2010.