In an initial ruling, the US International Trade Commission (ITC) found that GPS (Global Positioning System) chip maker SiRF infringed six Broadcom patents. The ruling, issued by Administrative Law Judge Carl Charneski, will be followed by a final decision in early December by a six-member panel.

The contentious patents, held by Broadcom subsidiary Global Locate, improve GPS processing and sensitivity, Broadcom said. A range of SiRF products, including those that include the SiRFstarIII and SiRFInstant GPS technologies, were found to infringe the patents, Broadcom said.

This is not the only dispute between the companies. An earlier ITC ruling in June found that Broadcom did not infringe two patents, as alleged by SiRF. In addition, Broadcom and Global Locate have filed patent-infringement lawsuits against SiRF in the US District Court for the Central District of California in Santa Ana.

"We are pleased that in two separate patent cases in front of two different ITC judges Broadcom has prevailed at trial, with rulings that support our position that SiRF infringes our intellectual property but that we do not infringe theirs," said David Rosmann, Broadcom's vice president of intellectual property.

Broadcom, a major communications processor vendor, bought Global Locate last year in order to be able to sell chips for mobile phones and other handheld devices that include GPS capabilities.

The market for GPS chips is heating up as an increasing number of mobile phones include the technology, partly due to government regulations in the US that require mobile operators to be able to locate wireless callers in emergency situations.

After the ruling was announced, SiRF was down more than 10 per cent after hours at $2.87. Broadcom's stock added 14 more cents in extended trading after gaining 57 cents to close at $26.01.

Broadcom Corporation is a Los Angeles-based supplier of integrated circuits (ICs) for broadband communications. Founded in 1991 by Henry Samueli (chairman and CTO) and Henry Nicholas, it became a public company in 1998 and now employs over 6,800 people worldwide. It had annual revenues of $3.78 billion last year.

SiRF Technology Holdings, Inc. is a publicly traded company that manufactures a range of patented GPS chipsets and software for consumer navigation devices and systems. The chips are based on ARM controllers integrated with low-noise radio receivers to decode GPS signals at very low signal levels. Based in San Jose, California, the company posted revenues of $329.4 million in 2007.