TAIWANESE SMARTPHONE MAKER HTC has fired its latest shot at Apple in the smartphone patent wars using patents that Google obtained last week.

HTC has been in a bitter and prolonged battle with Apple over smartphone patents allegedly infringed by its Android devices. Even though Apple didn’t name Google directly in its lawsuit, most observers heralded the fight as one between Apple and Google. Now it seems Google has effectively lent HTC a hand by giving HTC access to its patent portfolio to defend itself.

Bloomberg reports that HTC has filed infringement claims against Apple using nine patents that Google obtained just last week. The patents originally came from Palm, Motorola and Openwave Systems, but US Patent and Trademark Office records show that ownership was changed to Google on 1 September.

HTC filed its lawsuit with the US District Court in Delaware claiming that Apple is infringing four of those patents. Separately, HTC has amended a complaint with the US International Trade Commission alleging that Apple is infringing three patents first issued to Openwave and two originating from Palm.

Although these patents have nothing to do with Google’s proposed buyout of Motorola Mobility, it highlights just how important it is for Google to have a competitive patent portfolio in order to back up device manufacturers against Oracle, Apple and Microsoft. If Google can protect Android device makers with its stash of patents then the $12.5bn price tag on Motorola might turn out to be something of a bargain.

If Google’s patents have merit then it is likely that Samsung won’t wait too long before requesting access to them in order to stop Apple from obtaining import bans on its Galaxy tablets and smartphones all over the world.