The company said it would change four stations -- including stations in San Diego and Ann Arbor, Mich. -- to progressive talk within 60 days. The stations will carry Air America Radio's Al Franken and Randi Rhodes, as well as other syndicated talkers and local hosts.
"In certain local markets, listeners are clearly finding progressive talk radio entertaining and informative," said John Hogan, Clear Channel chief executive officer. "We've been delighted with the ratings generated by our progressive talk radio stations."
Clear Channel's Portland, Ore., outlet, KPOJ-AM, went from No. 26 to No. 3 among adults 25-64 after switching to progressive talk earlier this year.
In July, Clear Channel signed a deal to broadcast Air America Radio on its Miami outlet, WINZ-AM. The Palm Beach Post reported Clear Channel decided Air America Radio was a good fit for the Miami market -- given the success of Michael Moore's anti-Bush movie "Fahrenheit 9/11."
"We saw some impressive numbers from stations doing this format," said Clear Channel-Miami general manager Peter Bolger.
Notable deaths of 2014 [PHOTOS]