HTC has filed a counterclaim against Apple following the iPhone-maker’s original patent infringement lawsuit with the District Court of Delaware in the United States.

Defendants admit that some of the asserted patents purport to cover generally various software and/or hardware technologies that could be used in mobile communication devices and/or other products. Defendants otherwise lack knowledge or information sufficient to form a belief as to the truth of the allegations.

HTC counterclaim

Apple’s original suit was filed in April 2010, outlining infringements on 20 separate patents held by the company. HTC attempted to have another court halt imports and sales of Apple mobile devices the following month, setting the stage for a showdown between two of the world’s largest mobile phone manufacturers.

Apple has yet to respond to HTC’s latest claim.