An International Trade Commission judge has ruled that Xbox 360 violates four Motorola patents covering aspects of wireless networking and video coding featured in Microsoft's games console.
The ruling is subject to review by a six-member commission which has the power to ban imports that infringe US patents, Bloomberg reports.
Another ICT judge said that Motorola infringed one Microsoft patent. The commission will review all rulings and issue a final judgement by August 23, but it may ultimately mean Microsoft has to enter settlement talks with Motorola to avoid an Xbox import ban.
A Motorola spokeswoman said: "Microsoft continues to infringe Motorola Mobility's patent portfolio, and we remain confident in our position. This case was filed in response to Microsoft's litigate-first patent attack strategy, and we look forward to the full commission's ruling in August."
Microsoft also said: "Today's recommendation by the administrative law judge is the first step in the process leading to the commission's final ruling. We remain confident the commission will ultimately rule in Microsoft's favour in this case and that Motorola will be held to its promise to make its standard-essential patents available on fair and reasonable terms."