Emmis Communications, which owns 25 radio stations primarily in the United States, on Monday said it will begin selling Internet services to local media companies through Emmis Interactive, its online marketing division.

After decades as mere observers of the digital revolution occurring around it, the radio industry is now in the eye of the storm created by the Internet.

The industry has seen many of its younger listeners switch to digital forms of entertainment such as MP3 players and the Internet. And many radio advertisers have followed them.

Emmis Interactive, which will now operate as a wholly owned subsidiary of Emmis Operating Company, was launched five years ago as Emmis' effort to transform the Internet from a rival into a revenue opportunity.

The group, which is based in Chicago, has now opened its doors to other local media including radio stations, newspapers, and TV to assist them in extending their marketing and programming efforts to the Internet.

Emmis Interactive's main goal is to mask the technical complexity and disruption involved in the creation of web services that allow listeners to move easily back and forth from the station to the station's web site.

"We take the content creation out of the back room where a web master might be, and put it into the hands of the morning DJ or the radio news guy," said Chris Campbell, director of sales marketing for Emmis Interactive.

The company said it can measure what listeners like on the web with more precision than one can using traditional radio market metrics, which marketers have challenged over the years.

"Better analytics help advertisers make their brands much more interesting and engaging to the local audience," Mr. Campbell said. "These are very targeted niche audiences that have true affinity for the content."

The terrestrial radio industry which depends almost entirely on advertising for its revenue has now had four consecutive years of disappointing revenue results, according to BIA Financial Network.

The industry’s revenue has been recorded as $18.1 billion each year from 2004 to 2006, and it fell to $17.9 billion in 2007. BIA Financial projects the industry's revenue will fall another 3.1 percent in 2008.

"While it has been a rough several years for radio, the efforts it is making to engage its listeners online and through the digital airwaves will hopefully come to fruition in the next few years," said Mark Fratrick, vice president of BIA Financial.