WASHINGTON, Oct 3 (Reuters) - A federal appeals court on Thursday instructed the U.S. International Trade Commission to reconsider a ruling that gave Google Inc a victory over Microsoft Corp in a patent dispute.
Acting on an appeal by Microsoft, the U.S. Court of Appeals for the Federal Circuit found that the ITC erred in its reasoning when it found that the Google unit Motorola Mobility did not infringe a Microsoft graphical interface patent.
After a critical discussion of the ITC judge's reasoning, the appeals court said: "This conclusion requires reversal of the 133 patent non-infringement judgment."
But it also said it agreed with the ITC that Motorola Mobility had successfully changed its smartphones so they no longer infringed the patent.
It also found the ITC was correct in ruling that Motorola Mobility, which was acquired by Google during the legal fight, did not infringe three other patents.
The dispute is one of dozens globally between various smartphone makers. Google's Android system has become the top-selling smartphone operating system, ahead of mobile systems by Apple, Microsoft, Blackberry Ltd and others.
In the original case, the ITC found in May 2012 that Motorola Mobility infringed a patent for meeting-scheduling technology but did not infringe several other Microsoft patents. An order was issued banning infringing mobile phones from the marketplace.
Motorola Mobility says it removed the infringing software from its phones. Microsoft disagrees, and has filed a lawsuit against the U.S. Customs and Border Protection, accusing the agency of failing to properly enforce the ITC order.
Microsoft said it was happy with the appeals court decision.
"We're pleased the court determined Google unfairly uses Microsoft technology," said David Howard, corporate vice president and deputy general counsel. "Google is free to license our inventions, but we're equally pleased if Google makes product adjustments to avoid using them."
A Motorola Mobility spokesman also saw good news in the appeals court decision. "Today's favorable opinion confirms our position that our products don't infringe the Microsoft patents," said spokesman Matt Kallman.
U.S. courts continue to work during the shutdown of the federal government but the ITC is largely shut down.
The case at the ITC was No. 337-744. At the Federal Circuit, the case is No. 2012-1445, -1535.