Apple did not infringe patented technology owned by HTC , the U.S. International Trade Commission said on Friday, the latest ruling in the smartphone patent wars.

The specific complaint is a proxy for the larger fight for market share between Apple's products and Google's Android software for cellphones and tablets, many of which HTC makes.

Taiwan-based HTC had filed a complaint in 2010 accusing Apple of infringing five patents on technologies for power management and phone dialing. It asked the ITC to bar some versions of Apple's iPods, iPhones and iPads from being imported into the United States.

In October 2011, an Administrative Law Judge (ALJ) made an initial determination that identified no violation of four of HTC's asserted patents. HTC had originally also asserted -- but meanwhile withdrawn -- a fifth patent.

HTC asked the Commission to review the ALJ's preliminary ruling. In December, the Commission granted a review, but with respect to only one of the patents. Today's ruling terminates the investigation with respect to the sole remaining patent. HTC could appeal the ITC's final decision to the Federal Circuit.

"Specifically, the Commission has determined to reverse the Administrative Law Judge's finding that the "switching the PDA system from normal mode to sleep mode when the PDA system has been idle for a second period of time" limitation of claim 1 (patent) is met and affirm the ALJ's determination that the accused products do not meet the "implementing a power detection method comprising steps of: detecting an amount of power of a source in the power system; switching the mobile phone system to off mode when the detected amount is less than a first threshold; and switching the PDA system to off mode when the detected amount is less than a second threshold" limitations of claim 1," the Commission concluded.