On Tuesday, the ITC issued a limited order preventing sales and imports of AT&T models of the iPhone 4, iPhone 3GS, iPad 3G and iPad 2 3G. Samsung had also accused Apple of violating another three patents, but the ITC ruled that the Silicon Valley company did not infringe those.
The ITC ruled that Apple had infringed a standard essential patent covering 3G wireless technology.
The ruling reversed a September decision by ITC Judge James Gildea, who found that Apple did not infringe the patents. The case, 337-794, was filed in August 2011.
The case is the latest instalment in a long-running battle between the two companies over smartphone technology.
"We are disappointed that the commission has overturned an earlier ruling and we plan to appeal. Today’s decision has no impact on the availability of Apple products in the United States," Apple spokeswoman Kristin Huguet said in a statement.
Samsung issued a statement which said the ITC decision “confirmed Apple’s history of free-riding on Samsung’s technological innovations”.
“Our decades of research and development in mobile technologies will continue and we will continue to offer innovative products to consumers in the United States,” it read.
Apple has filed a separate ITC complaint, accusing Samsung of infringing two patents relating to its iPhone and iPad devices. An ITC judge ruled that Samsung infringed one patent but not the other. A final ruling on that case is expected in August.
