The US International Trade Commission said on Monday that Apple did not violate four patents held by HTC, which said it intends to appeal.
HTC had filed the complaint with the ITC in May of last year, alleging that Apple had violated patents relating to power-management methods and phone-number directories used in HTC mobile devices.
The company further requested that the ITC ban the import of certain Apple products to the U.S. that infringe on the patents. The complaint prompted the ITC to launch an investigation in June 2010, resulting in Monday's initial determination.
HTC said it had yet to receive the full opinion and analysis of the ITC's findings. But in a statement, HTC General Counsel Grace Lei said, "This is only one step of many in these legal proceedings. We are confident we have a strong case for the ITC appeals process and are fully prepared to protect our intellectual property."
Apple did not respond to a request for comment.
Both Apple and HTC have been locked in patent disputes with one another, with both asking the ITC to ban the sale of the other's products.
Monday's decision dealt another setback to HTC following a ruling in a separate ITC case.
Last year, Apple filed a complaint against HTC, alleging the company had infringed on its held patents. In July, the ITC gave an initial determination that ruled in favour of Apple. If the judgement is made final, HTC could be banned from importing phones to the US.