Apple filed a complaint last week with the Commission claiming HTC had infringed ten of the firm's patents. However, in preliminary findings, the ITC revealed it believed only two of the ten patents relating to the iPhone had been infringed.
The ITC findings must now be reviewed by a six-member committee. A final verdict is expected on December 6. If the complaint is upheld, the US may ban some HTC phones being imported into the country.
HTC said it will "vigorously fight these two remaining patents through an appeal before the ITC commissioners who make the final decision" along with maintaining it has never infringed any of Apple's patents.
"This is only one step of many in these legal proceedings."
It’s not the first time Apple has hit out at HTC. In March last year, Apple filed a lawsuit alleging that HTC infringed 20 of its patents relating to the user interface and the underlying architecture and hardware of the iPhone. However, HTC retaliated by filing a complaint with the ITC claiming Apple infringed five of its patents. While it did not reveal the technology covered in the patents, it did ask the ITC to halt the importation and sale of the iPhone, iPad and iPod in the US.