InterDigital, the US company that earlier complained Beijing was threatening it over its attempt to collect patent royalties from Chinese and other firms, lost its legal battle at the international trade court on Thursday.

The US International Trade Commission (ITC) has cleared Huawei Technologies, Nokia and ZTE of charges they infringed cellphone patents owned by InterDigital.

The wireless research and development company had accused the companies of violating seven patents used to make 3G wireless devices.

It has asked the ITC to ban sales of the three companies’ 3G mobile devices in the United States.

Nokia, a former leader in the telecoms market, is based in Finland, while ZTE and Huawei are Chinese multinational corporations.

William Merritt, the chief executive of InterDigital, said in a statement about the final ruling on Thursday: “Today’s determination by the ITC is extremely disappointing. We believe the commission’s claim constructions are plainly wrong, and we look forward to appealing the determination.”

InterDigital, which owns nearly 2,000 wireless technology patents, is still under investigation by China’s National Development and Reform Commission (NDRC) for allegedly violating Chinese anti-monopoly law.

InterDigital earlier said the Chinese government had threatened to arrest its employees as part of the investigation.

The NDRC said it launched the investigation because of InterDigital’s complaint to the ITC, a quasi-judicial independent body.