A US federal judge has clamped further restrictions on Qualcomm's ability to sell and support certain wireless chipsets, saying that they infringe on three patents held by rival Broadcom.

The injunction, issued by Judge James Selna, prohibits Qualcomm from making and selling certain 3G chipsets, used to provide Internet access to mobile phones. Qualcomm is also barred from engaging in a range of marketing and customer support activities related to its WCDMA and EV-DO (EVolution-Data Only) chips, which are used to process data on high-speed wireless networks.

The ruling is the latest in a series of actions in the long-running dispute between the two chip vendors. Last year, the US International Trade Commission (ITC) ruled that Qualcomm infringed Broadcom patents, and barred Qualcomm from importing chips to the US, but the Commission allowed mobile phone vendors to ship the chips in their products.

"The ITC order did not go nearly as far in prohibiting other activities from Qualcomm," said David Rosmann, vice president of intellectual property litigation with Broadcom. "The District Court order has in some respects much broader remedies. So the activities that are going to be barred by this injunction go a long way to stopping Qualcomm's continued operations in support of these infringing chips."

Broadcom sued Qualcomm in May 2005, claiming that Qualcomm's chips violated three of the company's patents. In May of this year, a jury found in Broadcom's favour and awarded the company US$19.6 million in damages. The injunction stems from that decision.