In another blow to Android, a judge at the U.S. International Trade Commission issued an initial determination that Motorola Mobility infringes four claims of a Microsoft patent. The judge also found that Motorola does not infringe claims related to six other Microsoft patents.
The notice follows an ITC decision on Monday to ban the importation of HTC Android products that infringe an Apple patent.
Both Motorola and Microsoft said they were pleased with the finding.
"We are very pleased that the majority of the rulings were favorable to Motorola Mobility," said Scott Offer, senior vice president and general counsel of Motorola Mobility, in a statement. "The ALJ's initial determination may provide clarity on the definition of the Microsoft 566 patent for which a violation was found and will help us avoid infringement of this patent in the U.S. market." Motorola also noted that Microsoft had previously dropped two patents from its initial complaint.
Microsoft referred to Samsung, HTC, Acer and others as choosing "the right path forward" in deciding to license patents from Microsoft.
"One key step behind us in the ITC. More to follow. But we'll also remain focused on licensing," Brad Smith, general counsel at Microsoft, wrote on Twitter.
Motorola, which has agreed to be acquired by Google, was one of the few large phone makers to battle Microsoft over mobile patents related to Android rather than sign a licensing deal. It did not immediately reply to a request for comment about the ITC notice. Motorola can now ask the full commission to review the initial determination.
Microsoft has declined to disclose which patents it has licensed to Android device makers, so it's unclear if it has been signing agreements for the patents that the ITC found Motorola is not infringing.
Patent number 6,370,566, which the administrative law judge at the ITC found Motorola infringes, describes generating meeting requests and group scheduling from a mobile device.
Motorola noted that it has accused Microsoft of infringing patents as well, both in courts and at the ITC. "Motorola Mobility remains confident in its position and will continue to move forward with its complaints," it said in the statement.
Android is being attacked in courts around the globe. In addition to Microsoft's actions, Apple has sued Samsung and Motorola in various courts over their Android products. In addition, Oracle is suing Google for patent infringement in Android.