Radio station owner Clear Channel Radio said Tuesday that it will buy part of digital music company Thumbplay Inc. so that its listeners can stream more music over the Internet using computers and smart phones.

The acquisition does not include Thumbplay's cell phone ringtone business. Terms of the purchase were not disclosed.

Clear Channel Radio owns 850 radio stations in over 150 cities, most of which people can listen to over the Internet, through the website iHeartRadio. Thumbplay, too, lets people listen to music over the Internet: It streams more than 8 million songs from major record labels such as EMI, Sony Music Entertainment, Universal Music Group and Warner Music Group.

Unlike websites such as Pandora, which create an online radio station inspired by a listener's favorite artists or songs, Thumbplay allows people to listen to the precise song they want to hear, when they want to hear it.

With Thumbplay's catalog of songs and ability to create musical playlists, Clear Channel's listeners will be able to stream music over the Internet, and not just traditional radio stations.

For Clear Channel, digital radio is a largely untapped market. It says the medium only accounts for 3 percent of the hours people spend listening to the radio.

Both iHeartRadio and Thumbplay currently work on Apple Inc.'s iPhone and iPod Touch, Research In Motion Ltd.'s BlackBerry smart phones as well as devices running Google Inc.'s popular Android software. To listen on mobile devices, users download applications, or "apps."