Apple has included twelve more patents to its lawsuit against Motorola, pushing the number of alleged infringements up to a total of twenty-four.

It was in October this year when handset manufacturer Motorola dragged Cupertino-based Apple blaming it of infringing eighteen patents relating to hardware and services.

Motorola blamed Apple of refusing to pay a license after long negotiations. Motorola said that the iPhone manufacturer breached its patents relating to 3G, GPRS, antenna design and wireless technologies.

Apple retaliated by claiming that Motorola’s Android-powered handsets breached a number of patents owned by Apple. As per Apple’s claims, Motorola mostly infringed its patents relating to multi-touch technology, set-top box and DVR technology.

Earlier, Apple sued HTC claiming it infringed phone patents owned by it. Speaking on the case against HTC, Apple CEO Steve Jobs had said,

“We can sit by and watch competitors steal our patented inventions, or we can do something about it. We've decided to do something about it."

The US International Trade Commission confirmed last week that it would launch a formal investigation in response to Apple's allegations.