Mobile maker Motorola has won a patent case against the Xbox console, in ruling that could cost Microsoft $4bn to meet the licensing demands.
A judge at the US International Trade Commission ruled that the firm infringed four patents owned by Motorola Mobility. The claims relate to technologies involved in the H.264 video compression standard and wi-fi connectivity.
The full commission will review the judgement in August.
Motorola is currently in the process of being taken over by Google. It disputes the $4bn figure Microsoft said it would cost year to pay for all of Motola’s licesnses.
If the final ruling goes against Microsoft and it does not settle, Motorola could theoretically force it to halt imports of the Xbox to the US.
A spokesman for Motorola said: “Microsoft continues to infringe Motorola Mobility’s patent portfolio, and we remain confident in our position.”
However, Microsoft signalled it planned to fight on, saying: “We remain confident the commission will ultimately rule in Microsoft’s favour.”