EXCLUSIVE: Hub Network president and CEO Margaret Loesch will be stepping down at the end of the year. The veteran executive oversaw the 2010 launch of the kids cable network, a joint venture between Discovery Communications and toymaker Hasbro, and has run it ever since. Loesch’s departure raises further questions about the future of the upstart kids cable network, which has been plagued by rumors that it may be shutting down. Hub, which replaced Discovery Kids, is not commenting on its plans for the future, though I’m hearing the name of a Discovery veteran — Tom Cosgrove, CEO of another Discovery co-venture channel, 3D Television Network — as a potential replacement. There is talk that Hub, which reaches nearly 73 million U.S. homes, may be re-branded, with its headquarters, currently based in Burbank, potentially moving to Discovery’s home base in Silver Spring, MD.

“After five years at the Hub Network as its founding President & CEO, I am announcing that I will be leaving at the end of the year when my contract expires,” Loesch said in a statement to Deadline. “I am very proud of the work we have done and the accomplishments we have achieved at the Hub. The network is now in excellent financial shape, its ratings are up year-to-year, our programming has won more than 30 awards, including 12 Daytime Emmys, and the Hub Network has become a TV home for quality programming that kids and their families come together to enjoy. I will be working closely with our parent companies, Discovery and Hasbro, to assist in the leadership transition. I want to thank both companies for the opportunity they extended me and thank my wonderful team at the Hub. I have loved my job and am proud of the achievements we’ve made. While my career has spanned over four decades, I look forward to evaluating future opportunities and writing the next chapter.”

Last fall, Hub marked an eighth consecutive quarter of ratings growth, and it has been inching up in the ratings year-vs-year. Yet, the network draws a fraction of the audience of Disney Channel and Nickelodeon and is still behind Nicktoons. In May, it averaged 114,000 viewers in total day, flat with its delivery in the first quarter of this year. Several shows have done well, like My Little Pony Friendship Is Magic, Transformers Prime Beast Hunters and The Aquabats!, with My Little Pony in particular credited with boosting merchandising sales for Hasbro. The toymaker also has stated that the network has started turning a profit, after running losses of $6 million-$7 million a year for the previous couple of year. Still, the Hub is a big investment for Hasbro, which shelled out $300 million for 50% of the network and has pumped an additional $200 million into its Hasbro Studios, which produces a large portion of the network’s programming.

Hub has been trying to gain ground in a crowded marketplace while kids advertizing has been steadily declining. To offset that, the network expanded into family-oriented programming, branding itself as “the only network dedicated to providing kids and families entertainment they can watch together.” It has been airing movies in primetime and earlier this week, Hub announced that it would run popular 1990s teen comedy series Blossom.

Another Discovery joint venture which replaced a Discovery cable network, OWN: The Oprah Winfrey Network, went through serious growing pains until finding success with Tyler Perry series. And recently, Discovery rebranded its Military Channel as American Heroes.

During her four decades in the kids programming business, Loesch has overseen the development or production of such hits as Smurfs, Mighty Morphin Power Rangers, X-Men, Jim Henson’s Muppet Babies, Animaniacs, Transformers and Bear in the Big Blue House. She was the first President and CEO of Crown Media United States, responsible for the creation of its Hallmark Channel; and President of Television, Worldwide, of the Jim Henson Group. Loesch was the founding President and CEO of Fox Kids Network, Worldwide. Prior to that she was President and CEO of Marvel Comics’ film production arm, Marvel Prods., and EVP of Hanna-Barbera Prods.