Limbaugh syndicator cancels national ads Right-wing radio talk show radio host Rush Limbaugh speaks at the Conservative Political Action Conference in Washington, Feb. 28, 2009. SHERMAN OAKS, Calif., March 13 (UPI) -- The syndicator of Rush Limbaugh's U.S. radio talk show said it was canceling all national commercials airing during the show for two weeks, a Web site reported. Premiere Networks, the largest U.S. radio syndication company based on programming popularity, said in a memo to affiliate-station managers it suspended the national commercials airing on "The Rush Limbaugh Show" from Monday through March 19, Radio-Info.com reported. While some radio stations pay huge fees to air Limbaugh's program, many air it for free or at low cost, provided they let Premiere run several minutes of national advertising every hour. The stations also run their own local commercials. Premiere offered no reason for the suspension of national advertising for two weeks. "I suspect they want to make sure that nothing happens, that there's no friction on the air involving an advertiser," Radio-Info.com Editor Tom Taylor told MSNBC. Premiere -- which also syndicates "The Glenn Beck Program," "The Sean Hannity Show" and "Coast to Coast AM" among other programs -- said in a response to the Radio-Info.com story, "This memo was sent to traffic managers of news/talk affiliates as part of Premiere's overall strategy to update our processes and services to better meet our clients' needs." Traffic managers schedule advertisements radio and TV stations. Limbaugh publicly apologized March 3 for words he used when he called Georgetown law school student Sandra Fluke a "slut" and a "prostitute" on the air, after she testified in support of the Obama administration's requirement that health-insurance plans cover contraceptives for women. Limbaugh talked about Fluke at length for three days, focusing on her sex life and criticizing her advocacy for contraception coverage. After liberal groups launched a campaign calling for advertisers to boycott Limbaugh's show, scores of sponsors said they were suspending their commercials. The ThinkProgress political blog cited a separate Premiere memo Monday as saying nearly 100 previously unreported national advertisers have asked that their ads not be played on the show, bringing the total in the wake of the "slut" controversy to 141. Limbaugh was away from his program Monday. Fill-in host Mark Steyn joked Limbaugh had given himself a suspension for the day and was playing golf.