Broadcom Corp. said that the International Trade Commission (ITC) has commenced an investigation tied to allegations that Microtune Inc. infringed on two Broadcom patents.

In charges that Broadcom most recently brought to light in January, the chipmaker has further alleged that Microtune engaged in unfair trade practices by importing tuners, power amplifiers and Bluetooth products.

Broadcom, in its March 3 filing with the ITC, is seeking to bar Microtune from importing into the U.S. those devices, plus cable modems, set-tops, PCTV cards and Bluetooth-based headsets that use Microtune chipsets.

If the ITC agrees to an exclusion order, Microtune's allegedly infringing products would be barred from importation to the U.S., Broadcom claimed.

Broadcom's charges against Microtune marks the latest salvo in string of legal skirmishes between the two companies. Microtune, however, has enjoyed the upper hand, so far.

In March, a Texas jury ruled in favor of Microtune in a separate patent infringement case brought against Broadcom. In that case, the jury found that Broadcom's BCM 3415 microchip infringed on Microtune's patent for a "highly integrated television tuner on a single microcircuit."

Microtune Chairman and CEO Doug Bartek said a court hearing is set for April 11 to determine an injunction date in that case. That date must be determined before the court decides the amount of financial damages, if any, will be awarded to Microtune.