The US International Trade Commission (ITC) banned the import of older versions of some Apple mobile devices, after ruling that the iPhone maker had violated a patent held by Samsung.

In the latest development in the long-running patent battle between the smartphone giants, the ITC said the Cupertino-based company had infringed a patent held by the South Korean giant, and issued a “limited exclusion order” prohibiting Apple from importing “communications devices, portable music and data processing devices, and tablet computers” which use the intellectual property.

A cease and desist order has also been issued, prohibiting the sale and distribution in the US of the same Apple devices.

The impact of the judgement is likely to be limited, however, because it does not concern Apple’s latest devices.

The complaint covers the AT&T versions of the iPhone 4, iPhone 3GS, iPhone 3 and iPad 3G and iPad 2 3G, but Samsung has reserved the right to allege infringement by Apple products offered by other operators.

The allegedly 3G-essential ‘348 patent covers the encoding and decoding of data transmitted on CDMA networks. The ITC found that Apple failed to defend itself based on Samsung’s FRAND declarations.

Newer iPhones and iPads use Qualcomm baseband chips which do not infringe the patent, meaning the ruling won’t affect the import or sale of these devices.

Apple will be able to continue importing the devices during a 60-day Presidential Review period and if the White House does not veto the ruling, and an appeal by Apple fails, the import and sales ban will be implemented.

The ITC investigation started in August 2011 after Samsung filed a complaint alleging that Apple violated section 337 of the Tariff Act by selling electronic devices that violated five (later four) patents. The ITC found Apple did not violate the three other patents.