The International Trade Commission, an obscure administrative body that has become an increasingly popular venue for patent disputes, has sided with Apple in its fight against Motorola Mobility.

The Google subsidiary filed a complaint with the ITC in 2010 alleging that Apple had violated 18 Motorola patents. The company asked the panel to ban iPhone imports. After siding with Apple on other patents earlier in the process, the ITC rejected Motorola's final remaining patent in a Monday ruling.

Monday's decision focused on Patent No. 6,246,862, "Sensor controlled user interface for portable communication device." It covers the concept of using a proximity sensor to automatically disable a device's touchscreen. This technique is used by the iPhone and other modern smart phones to avoid accidental input when the user puts the phone to his or her face to make a phone call. The ITC concluded that the concept was too obvious to merit patent protection.

The fight at the ITC is just one front in the sprawling patent battle between Apple and Motorola. Federal judges have thrown out lawsuits between the firms in Illinois, Wisconsin, and Florida. The companies are also fighting over patents in Germany, where Apple won a sales ban on some Motorola products last September.

A Google spokesman told Bloomberg that the company was "evaluating our options." Apple had no comment.