WASHINGTON May 23 (Reuters) - Microsoft Corp won a round in a complex patent war on Thursday when the International Trade Commission said the company's popular Xbox entertainment system did not violate a patent owned by Google subsidiary Motorola Mobility.
If the ITC had found that Microsoft infringed, it could have barred the Xbox from being imported into the United States.
The fight over the Xbox is related to a larger smartphone patent war between Apple, Microsoft and the mobile phone makers who use Google's Android software, including Motorola Mobility.
Motorola Mobility originally accused Microsoft of infringing upon five patents when it filed its complaint in 2010. Four were dropped in ensuing months, leaving just one - a patent which allows devices to communicate wirelessly over short distances.
"This is a win for Xbox customers and confirms our view that Google had no grounds to block our products," David Howard, a Microsoft deputy general counsel, said in a statement.
Motorola was "disappointed with this decision" and is evaluating its options, a company spokesman said in a statement.
Technology companies have spent billions of dollars to buy patent portfolios, and still more money litigating patent cases around the world.
The Xbox case has seen many twists and turns since it was filed in late 2010.
In April 2012, ITC Judge David Shaw said in a preliminary decision that Microsoft infringed four patents and did not infringe on a fifth. But instead of deciding the case, as is usual, in June 2012, the trade panel sent the case back to the judge for reconsideration.
In January, following an antitrust settlement with federal regulators, Google asked a trade panel to drop two patents from the complaint because they were essential to a standard. These types of patents ensure interoperability and get special treatment.
Google had promised the Federal Trade Commission that it would no longer request sales bans based on the infringement of standard essential patents.
By that time, just one patent remained. In March, an ITC judge said that Microsoft did not infringe that technology and recommended that the case be terminated. The full ITC followed that recommendation on Thursday.
The case is at the International Trade Commission, No. 337-752.