The ITC’s final decision in the case is expected to be issued in October.
InterDigital, which buys and licenses patents, had accused the companies of violating seven patents used to make 3G wireless devices. The patents cover conservation of power and ensuring the right data goes to the right recipient, among other technology.
LG Electronics had been named in the original complaint but settled with InterDigital.
InterDigital asked the ITC to ban the US sales of the three companies’ 3G wireless mobile devices. While much of the world is moving to 4G, 3G remains broadly in use.
The ITC, a quasi-judicial federal agency, is a popular venue for patent fights because its docket moves fairly quickly and it can order a sales ban for any device which infringes a patent.