Ericsson’s attempt to have the iPhone banned from US sale over a patent dispute moved one step forward yesterday as the ITC agreed to investigate. Ericsson claims that iPhones infringe a number of its patents for fundamental cellphone technologies, including both GSM and LTE. Apple denies any infringement, and says that Ericsson is in any case demanding unreasonable amounts.

In an attempt to up the ante, Ericsson called on the U.S. International Trade Commission to block imports of the iPhone into the country, and the ITC has now agreed to carry out an investigation, reports PC World.

The ITC did previously apply a limited ban to the iPhone 3GS, iPhone 4 and 3G iPads over a patent claim by Samsung (later overturned by President Obama), but in this case it seems likely that Ericsson is merely hoping that the possibility will force a faster settlement than would be reached through the courts.