As part of the deal, Clear Channel will add Cumulus’570 radio stations to its iHeartRadio online listening service. In exchange, Clear Channel will share in some of the financial benefits of Cumulus’daily deals business called SweetJack.

Both station groups will advertise SweetJack bargains on radio stations in more than 60 markets where SweetJack is in business, including San Francisco, New York, Dallas and Atlanta. More markets are expected to be added soon.

Clear Channel, which is privately held, owns about 850 radio stations nationwide and is the top radio broadcaster in the nation, reaching 238 million listeners a month. Cumulus, a publicly listed company, is ranked third with 570 stations.

Clear Channel kicked off its iHeartRadio online radio service in September in a challenge to market leader Pandora Media Inc. Both services allow online listening over mobile devices to music that fits certain genres or sounds based on artists. Clear Channel is keeping this so-called “custom station” service free of ads through April 1 to build up its audience.

Clear Channel also offers streams of radio stations from different cities, which come with ads.

By tying up with Cumulus, Clear Channel is taking a stab at another booming online business – that of online coupons – led by upstart Groupon Inc.

Clear Channel Radio CEO John Hogan said the deal shows that traditional radio companies are staying relevant with tech-savvy consumers.

“It shows we can and do compete effectively in the digital space,” he said in an interview.

The deal will enable Cumulus to turn SweetJack into “a true nationwide platform,” and help it compete among many daily deal sites such as LivingSocial, said Cumulus CEO Lew Dickey in a statement.