A U.S. trade panel that hears patent disputes has agreed to investigate Apple Inc's complaint that mobile phones and tablets made by South Korean rival Samsung Electronics Co Ltd violate its technology intellectual property.

The world's most valuable technology company and Samsung are waging an escalating legal battle in multiple countries, accusing each other of infringing on technology and design patents as competition in the red-hot mobile gadgets arena intensifies.

Apple filed a complaint with the International Trade Commission, an independent federal agency, on July 5, seeking to block its South Korean foe from importing a plethora of Galaxy electronic devices. That came less than a week after Samsung also sought to stop imports of Apple's popular iPads and iPhones.

On Tuesday, the ITC said in a statement it voted to institute an investigation into Apple's claim and its request for a cease and desist order, spanning mobile handsets, tablets, software, touchpads and hardware interfaces.

Galaxy products use Google Inc's Android operating system, the closest competitor to Apple's iOS mobile software.

The intensifying patent dispute threatens to strain a lucrative supply relationship: Apple in 2010 was Samsung's second-largest customer, accounting for $5.7 billion of sales tied mainly to semiconductors, according to the Asian consumer electronics company's annual report.

Apple's complaint is In re: Certain Electronic Digital Media Devices and Components Thereof, U.S. International Trade Commission, No. 2827. Samsung's complaint is In re: Mobile Electronic Devices, Including Wireless Communication Devices, Portable Music and Data Processing Devices, and Tablet Computers at the same agency, No. 2824.

(Reporting by Edwin Chan, editing by Gerald E. McCormick)