• by Erik Sass  @eriksass1, January 9, 2012

Facing a powerful incumbent in the form of Pandora, radio groups that compete in the broadcast realm are closing ranks online, joining forces to build wider selections of content offerings for listeners while achieving greater scale for advertisers.

In the latest tie-up, Clear Channel Radio and Greater Media have struck a deal to bring online streaming audio from GM’s 22 radio stations to CCR’s digital iHeartRadio platform.

The addition of GM stations in Boston, Philadelphia, Charlotte, Detroit, and New Jersey will bring the total number of content options on iHeartRadio to over 1,370 broadcast and pure-play digital radio stations, including local stations from 150 cities across the U.S.

This is the third such deal for CCR and iHeartRadio. In early December 2011, CCR announced an agreement with Cumulus Media that will bring audio content from the latter’s 570 stations around the country to the iHeartRadio platform beginning in March or April of this year. Cumulus stations will advertise iHeartRadio on-air and feature a link to iHeartRadio on their station Web sites, while continuing to stream audio via those Web sites and their own mobile apps.

Clear Channel stations will begin promoting Cumulus’ SweetJack daily deals social commerce service.

In September, CCR revealed that it was adding Spanish-language programming from Univision Radio to the New iHeartRadio platform. The content partnership -- the first third-party distribution relationship for the digital platform -- includes music, sports, and talk formats, as well as leading AM and FM Spanish-language radio personalities.