HTC, which had been accused of infringing 10 Apple patents, said that it had been found to infringe just two, HTC said in a statement on Friday.
HTC said it would vigorously fight the infringement finding.
An International Trade Commission judge made the ruling in an initial determination, HTC said. The full commission must now rule on whether it will uphold or reverse its administrative judge's decision.
The ITC is a popular venue for patent disputes because it can bar the importation of devices made with infringing technology. Often parallel lawsuits are filed in district courts to try to recoup any financial damages.
We are confident we have a strong case for the ITC appeals process and are fully prepared to defend ourselves using all means possible, said HTC General Counsel Grace Lei in an email statement.