Kevin Clash, the puppeteer on PBS's "Sesame Street" who has performed as Elmo the past 27 years, has been placed on leave from the show following allegations that he had a sexual relationship with a 16-year-old boy. Show producer Sesame Workshop said the allegations were made in June by a man who is now 23. He says he was 16 when he began a relationship with Clash. The puppeteer denies the claims, and Sesame Workshop also says the allegations are unsubstantiated.

Syndicated entertainment newsmagazine "Entertainment Tonight" has named Rob Marciano co-anchor, working alongside Nancy O'Dell beginning in January. Marciano joins the show from CNN, where he had been a news and weather anchor.

Seattle agency Frank Unlimited has named LeeAnna Buis media director, replacing the departed Tonya Murphy. Buis was previously senior manager in charge of media at Virgen Advertising in Las Vegas.

Steve Marino has been named chief operating officer at agencyQ, a digital agency based in Washington, D.C. Marino was previously North American director of digital and social media at MSLGroup.

Susanne Daniels, a veteran of The WB and Lifetime, has joined MTV, taking over as presidento of programming for David Janollari, who has decided to leave. Daniels shepherded such programs as "Dawson's Creek" and "Buffy the Vampire Slayer" on the air at the WB. She most recently was a consultant for the Oprah Winfrey Network.

Comedy Central has promoted Gary S. Mann to senior vice president of original programming and development, based in the network's Santa Monica, Calif., office. Mann joined Comedy Central in 2003, and before that he was at HBO Independent Productions.

Louis C.K., the comedian and star of FX's "Louie," is set to star in a standup comedy special on HBO to air in 2013. The special, the comedian's fourth to air on HBO, will be shot during C.K.’s current tour.

Popular Mechanics magazine has named Mike Austin automotive editor, effective Nov. 26. Austin joins from Car and Driver, where he was technical editor.

Rodale has named Kristen Zohn account director at Organic Gardening magazine, reporting to publisher Jeff Tkach. Zohn had been senior partner and associate director of print communications at GroupM.

Brenda Saget Darling has been named associate publisher at House Beautiful magazine, as well as group digital director for Hearst Design Group. Saget Darling was most recently vice president and publisher for print and digital initiatives at Dwell magazine.

Time Inc. has promoted Tony Haskel to vice president of advertising sales at Money magazine, effective immediately. Haskel had been at Time Inc.'s Fortune magazine as executive sales director.

Video advertising technology company Extreme Reach has brought in Chip Scully, naming him vice president of online video advertising. Scully had been senior director of advanced TV and online video sales at Microsoft.

Tags: Brenda Saget Darling, Chip Scully, David Janollari, Jeff Tkach, kevin clash, Kristen Zohn, Mike Austin, Rob Marciano, Tonya Murphy