The ITC issued a ruling saying that the Microsoft company's popular Xbox entertainment system did not violate a patent owned by Google subsidiary Motorola Mobility.

In April 2012, ITC Judge David Shaw made a preliminary decision that Microsoft had infringed on four patents and did not infringe on a fifth. In June 2012, the trade panel sent the case back to the judge for reconsideration. By January all but one patent had been dropped from the case.

The Financial Express reports that 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.