The U.S. International Trade Commission (USITC) has voted to institute an investigation of Apple's smart phones that use image processing technology ver a patent infringement complaint filed by computer graphics firm S3 Graphics.

The investigation is based on a complaint filed by S3 Graphics. The complaint alleges violations of section 337 of the Tariff Act of 1930 in the importation into the United States and sale of certain electronic devices with image processing systems, components thereof, and associated software that infringe patents asserted by S3 Graphics. The USITC has identified Apple Inc. as the respondent in this investigation. S3 Graphics request that the USITC issue an exclusion order and a cease and desist order.

By instituting this investigation (337-TA-724), the USITC has not yet made any decision on the merits of the case. The USITC's Chief Administrative Law Judge will assign the case to one of the USITC's six administrative law judges (ALJ), who will schedule and hold an evidentiary hearing. The ALJ will make an initial determination as to whether there is a violation of section 337; that initial determination is subject to review by the Commission.

The ITC said it will make a final determination in the investigation ?at the earliest practicable time?. Within 45 days after beginning the investigation, the regulator will set a target date for completion.

Apple has been in trouble with regulators frequently in recent months, most notably its long running dispute with handset maker HTC, and also Kodak.

Both Apple and HTC have sued each other for patent infringement relating to smartphone technology.

Nokia has also filed a legal action against Apple, claiming that the iPhone and iPad 3G products infringe on five Nokia patents relating to enhanced speech and data transmission.