Rush of interest attends Limbaugh's return.

For KFI-AM (640), adversity is about to pay a dividend.

Rush Limbaugh, the undisputed king of talk radio, is due back behind the microphone this week after being in a drug rehab for an addiction to prescription painkillers--and for the Clear Channel Communications Inc.-owned station, there could be bigger audiences than ever.

With an estimated 20 million listeners nationwide, Limbaugh, who is syndicated through Clear Channel's Premiere Radio Networks, has the No. 1-rated talk show in the country. In Los Angeles, as elsewhere, he has helped propel the station that carries him to the top spot in the AM market.

While some stations and listeners grumbled about the hosts selected to fill-in for him during his absence, the ratings for his show haven't suffered. Now they may get a boost.

"I think it will be big doings," Neil Saavedra, director of marketing for KFI, said of Limbaugh's return. "There's always going to be lookieloos and hopefully anybody who samples the product will stick around."

Mary Jo Sobotka, vice president of media for Phelps Group, a Los Angeles advertising agency, expects that "a lot of people are going to tune in to hear about his adventures in rehab and how he is going to spin things. I can definitely see how this would benefit him audience-wise."

Although a clearer picture will emerge in January with complete results from the fall ratings period, early indications are that KFI has held its own over the past five weeks.

Preliminary Arbitron Inc. data for October show that between l0 a.m. and 3 p.m. KFI garnered a 3.6 rating, compared with a 3.5 rating in the three-month summer ratings period. (Limbaugh's show airs from 9 a.m. to noon on KFI).

Among KFI's local talk competitors, KABC-AM (790) stayed flat with a 1.8 rating in October, while KRLA-AM (870) improved to a 1.5 last month from a 1.4 during the sum met.

"Audience in L.A. did not drop off in October for mid-days," said Kathy Begley, vice president and broadcast director for Initiative Media. "(Limbaugh) couldn't have been off at a better time considering all the news with the California recall election, supermarket strikes, mass transit strikes and fires. These events contributed to increased audience levels for stations like KFI."

Anchored by a lineup that includes Bill Handel, Phil Hendrie and Dr. Laura Schlessinger, in addition to Limbaugh, KFI has dominated its talk competitors in recent years.

Whether out of respect for Limbaugh, who is credited with revitalizing AM radio in the 1990s, or because it wasn't considered a wise strategy to lure his viewers by kicking Limbaugh when he was down, KFI's competitors did not aggressively go after his listeners.

KABC, which for the past 18 months has run Fox News personality Bill O'Reilly against Limbaugh, has made some incremental gains against KFI, although Limbaugh still dominates his time period among listeners 25 to 64.

"Other than being on top of our game and knowing that some listeners are shopping around in Rush's absence, we're not doing anything that would be opportunistic," said Erik Braverman, operations director at KABC.

Tom Tradup, national program director news and talk for Salem Communications Corp., which owns KRLA, went so far as to send a note to all of his station managers reminding them to take the high road.

Not everyone was so magnanimous. Tom Leykis, whose syndicated show airs in Los Angeles on FM talk station KLSX (97.1), offered to wave his talent fee to record ads for any business that switched from Limbaugh's show to his. At least one apparently took him up on the offer.

Bob Moore, vice president and general manager for KLSX, is among those who believe that Limbaugh's drug revelations and the racially tinged comments that caused him to be fired this fall as a commentator for ESPN will take a toll.

"Nobody is going to say that Limbaugh is over but I think that advertisers, listeners and radio stations are going to look at him a different way," Moore said. "It's a major topic of conversation. He pretended to be someone he wasn't."