Tellemcbs2My sources are telling me that Nancy Tellem has gone to her boss Les Moonves to discuss stepping down from her longtime post at CBS as Les’ right hand exec. “No final decision will be made until she returns from MIPCom in Europe,” an insider informs me. But I’m told what’s contemplated by the 55-year-old president of the CBS Television Studios Entertainment Group is to move into a consultancy role sometime within the next 3 weeks. Nobody would take her place, but president of CBS Entertainment Nina Tassler would take on more responsibilities. About why Tellem wants out, I’m told: “She’s just done. She’s thinking about what the next chapter is for her life.” If she’s not replaced, then this leaves questions about succession for the 60-year-old Moonves because Wall Street doesn’t like for its publicly traded corporations to not have an heir apparent in place.

Along with ABC’s Anne Sweeney, Tellem has long been at the top among female executives in the television community and one of the best. And throughout her more than 25 years in the small screen biz, she has worked with Les Moonves and now reports to him directly. Relationships like that just don’t happen very often in Hollywood. Moonves and Tellem may talk by phone two or three times a day, and after so many years together, they don’t hold back. “We yell and we scream at each other, but when that’s over, she’s family,” Moonves once told BusinessWeek.

Profiles of this daughter of an anesthesiologist mom and surgeon dad make the point that she got hooked on TV as a girl through fan magazines which the networks used to mail out in the summers to promote new shows. Tellem began as a practicing lawyer in Los Angeles where in the early 1980s she was chasing down people who claimed to be heirs to Howard Hughes’s estate. When she jumped into entertainment, she was the legal expert on F. Lee Bailey’s 1982 show Lie Detector, worked for Merv Griffin on his Wheel of Fortune, then moved to Lorimar Productions, where she met Moonves.

 Her first major position was in the legal affairs department of Lorimar Television, which then merged with Warner Bros television. When Moonves became head of that in 1987, he promoted Tellem to EVP for Business and Financial Affairs; as the second highest-ranking executive, she helped Moonves make and maintain Warner Bros the dominant supplier of series to the networks. When Moonves jumped to become topper of CBS Entertainment in 1995, he appointed Tellem in 1997 as EVP of Business Affairs for CBS Entertainment, and then moved her over to creative to EVP of CBS Productions. In 1998, when Moonves was again promoted and became the president of CBS, Tellem succeeded Moonves as president of CBS Entertainment, overseeing all of CBS Entertainment’s programming operations for prime time, daytime, late night and Saturday morning, and eventually CBS.com.

She was promoted to the position of President, CBS Television Studios Entertainment Group (formerly Paramount Network Television Entertainment Group) in September 2004. CBS itself became a new entity, split from parent Viacom Inc. (VIA ) in January 2006, to create a more focused TV and radio operation. Its dependence on advertising has been a big problem during this financial crisis, giving both Moonves and Tellem real headaches as the stock plummetted.

Tellem is responsible for all entertainment operations at the CBS Television Network and the CBS Television Studios production studio — including development, programming, production, legal and business affairs. Under her and Moonves, CBS became America’s most watched network and is catching up on key demos, a big change from the geriatric fixer-upper they inherited. 

Tellem also has been spearheading the company’s efforts to expand its content into new media and across all emerging platforms, including the development and production of original content for CBS.com, the new CBS Audience Network and wireless. Tellem has overseen CBS’s entry into the wireless arena, securing licensing agreements with Verizon’s V-Cast, AT&T and Sprint as well as an agreement with MediaFLO USA where full episodes of CBS programming are delivered over their new mobile network. She has also led the company’s recent launch of CBS Records, a new music label — reporting to Tellem — that utilizes CBS’s television and digital platforms to market and distribute new music. CBS Consumer Products, a newly formed licensing and merchandising unit, also reports to Tellem.

Additionally, Tellem oversees CBS’s interests in The CW, the fifth broadcast network which is a joint venture between CBS Corporation and Warner Bros Entertainment. Under Tellem’s leadership, programs like CSI: CRIME SCENE INVESTIGATION, THE AMAZING RACE, CSI: MIAMI, CSI: NY, WITHOUT A TRACE, TWO AND A HALF MEN, COLD CASE, CRIMINAL MINDS, GHOST WHISPERER and HOW I MET YOUR MOTHER have aired. She also was a key part of the development of the SURVIVOR Reality TV series.