The radio industry, in a move to take on growing competition from satellite radio, iPods and the Internet, has formed an alliance to step up the rollout of digital radio.

The group's goal is to offer new and compelling content using "high-definition" digital radio technology, which produces CD-quality sound and eliminates the static, hiss and fades associated with analog signals, top radio executives said Tuesday at a press briefing unveiling the alliance.

So far, about 600 out of more than 10,000 radio stations across the United States have started digital broadcasts. HD radio is free, but consumers need to purchase pricey digital radio receivers to listen to broadcasts.

The alliance — which has at least seven radio companies on board including giants Clear Channel Communications Inc. and Viacom Inc.'s Infinity — hopes its efforts will drive down the cost of digital receivers as they catch on with more consumers.

The group, called HD Digital Radio Alliance, will coordinate the rollout of HD digital radio, including who will get to air what on new "multicast" channels. Through multicasting, which involves the split of radio frequencies into niche channels, a radio station can use the extra space for alternate programming.