Financial terms weren't disclosed.
Limbaugh's politically-oriented talk program has been at or near the top of the Arbitron ratings for several years, making it a huge cash cow for Jacor (JCOR).
The three-hour broadcast is heard weekdays on more than 600 radio stations across the country, reaching more than 20 million listeners each week.
Art Bell's show, which explores various extra-terrestrial themes, conspiracy theories and paranormal phenomena, will be carried on a live video feed over the Web. Viewers will be able to watch Bell conducting the program from his studio.
The late-night radio show has also been a consistent ratings winner and reaches more than 7 million listeners.
Jacor shares slipped 5/32 to 69 19/32, while Broadcast.com stock rose 2 to 85 13/16.
Jacor is one of the nation's largest radio companies. Clear Channel Communications' (CCU) $4.4 billion acquisition of the company, announced last October, is expected to close by the end of the third quarter.
Broadcast.com (BCST) broadcasts on the Internet 24 hours a day, seven days a week, and its programming includes more than 370 radio stations and networks, 30 television stations and cable networks, and game broadcasts and other programming for over 420 college and professional sports teams.
Written By David B. Wilkerson, CBS MarketWatch