Taiwanese smartphone maker HTC has been dealt a big blow in its legal battle with Apple involving patent infringement claims. The US International Trade Commission (ITC) has ruled that Apple did not violate patents as claimed by HTC in a complaint lodged last year. HTC had asked the court to ban imports of several Apple products in to the US citing patent infringements. HTC's shares fell as much as 6% after the ruling. The case involved four patents held by HTC related to protecting data, storing contact information and managing the phone's power supply. 'Confident' The judgement is another setback for HTC which is involved in a long and bitter battle with Apple. In July this year, the Taiwanese phonemaker was found to have infringed two iPhone patents in a case brought by Apple at the ITC. However, HTC said that despite the judgement, it was sticking to its claims. "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," said Grace Lei, HTC's general counsel. "We look forward to resolving this case, so we can continue creating the most innovative mobile experiences for consumers." A full commission of the ITC is expected to decide in February, whether to uphold or reject the judge's decision.