Chinese telecom equipment vendors Huawei Technologies Co Ltd and ZTE Corp have secured their second victory against a lawsuit claiming they infringed on patent rights in the United States.

The United States International Trade Commission ruled on Sept 6 that the two companies did not infringe on the patent rights of several companies in the US. The investigation was launched a year ago.

It marked their second victory in four months. In June, the two companies won a similar victory against InterDigital, which is located in the US and had accused Chinese companies, including Huawei and ZTE, of patent infringements on its wireless technologies.

China's Ministry of Commerce said on Thursday that Huawei and ZTE won the second ruling despite a difficult process.

"It reflects these companies' competitiveness in an objective way and boosts their confidence in facing investigations," the ministry said.