Clear Channel Radio announced that it is extending its commercial-free programming on iHeartRadio’s Custom Stations through April 1, 2012, after initially planning on stopping this at the year’s end.

They must want to keep their momentum in competing with Pandora going strong.

The new iHeartRadio launched in September. It used be basically a way to listen to radio stations from around the country, and that was pretty nice on its own, but the new version keeps that functionality and adds a Pandora-like feature that lets users create their own stations based on songs or artists that they like. So far, these custom stations have not had ads, and users like that, so extending the no-ad time should be pretty good for continuing to win over new users who are tired of the ads on the free version of Pandora.

A Clear Channel spokesperson tells WebProNews they’re “beginning to work with advertisers to eventually integrate commercials into the service in a way that delivers real value to them while being acceptable to listeners.”

“The New iHeartRadio has exceeded our expectations – and more importantly, those of our fans – since it launched in September at the iHeartRadio Music Festival in Las Vegas. It offers our listeners everything they want from a digital radio service in one completely integrated, free experience,” said Brian Lakamp, President of Clear Channel Digital. “Because Custom Stations are only a feature of the New iHeartRadio, we have the luxury of being able to extend our commercial-free Custom Stations till April 1, 2012.”

Clear Channels notes that iHeartRadio is consistently in the top 10 downloads of free music apps for the iPhone and in the top five for Android.

It logs 65 million listening hours a month, and the mobile apps have been downloaded 44 million times. The iHeartRadio is currently available at iHeart.com and on iOS and Android.