Microtune Inc. claimed victory in its latest legal scuffle with silicon tuner rival Broadcom Corp.

According to Microtune, U.S. International Trade Commission (ITC) Judge Sidney Harris made an initial determination on April 2 that single-chip tuners and amplifiers imported by Microtune did not infringe on a Broadcom patent (No. 6,445,039).

The judge ruled that Broadcom's patent "was invalid on numerous grounds, making the issue of infringement irrelevant." Broadcom can petition the ITC to review the initial determination, however. A final ITC determination should be released by July 2.

"We feel vindicated in defending our single-chip tuner technology, which we pioneered and patented," said Microtune CEO and president James Fontaine, in a release.

The ITC investigation first came to light in April 2003. Broadcom, which made the filing in the previous month, sought to bar Microtune from importing its tuners, power amplifiers and Bluetooth products into the U.S.

The ITC ruling is just the latest result of a flurry of legal activity between the two companies. Last March, a Texas Jury ruled in favor of Microtune in separate patent infringement case brought against Broadcom. There, the jury found that Broadcom's BCM 3415 microchip infringed on Microtune's patent for a "highly integrated television tuner on a single microcircuit."

Broadcom had also sued Microtune for infringement over another patent (No. 6,337,315), but later withdrew the suit.

Three other cases between the two companies are still pending, Microtune said. Among them, two are patent-related. In the third, Microtune has filed an anti-trust suit, alleging that Broadcom has engaged in unfair business practices.