After nearly 15 years with the company, Christina Miller, President of Warner Media’s Cartoon Network, Adult Swim, Boomerang and TCM, announced today that she would be leaving at the end of the year.

Michael Ouweleen, EVP/ Chief Marketing Officer, Cartoon Network, Adult Swim and Boomerang, will serve as the interim president, and Miller will help with the transition.

“This is not a decision I came to lightly,” said Miller. “It’s one of the hardest I’ve had to make in my career. Ultimately, it feels like the right time for me to leave and take a little time to think about what comes next, but I do so, feeling immensely proud of the work we’ve done together and so grateful for the experience.”

This marks the latest top-level executive departure at a WarnerMedia network following the completion of AT&T’s acquisition of Time Warner, which triggered a major executive restructuring. According to sources, Miller was asked to stay on by the new WarnerMedia leadership but opted to Christina Miller Stepping Down As President Of Warner Media’s Cartoon Network

“Christina has been a respected and impactful leader since she joined the company, said Ann Sarnoff, Chair and CEO, Warner Bros. “We wish her the best of luck in the next chapter of her career, where I know she’ll continue to enjoy great success.”

Miller has led the Kids and Young Adults division for the last five years where she was responsible for all aspects of the business including global oversight of content development and production and franchise management. Her leadership also extended to Christina Miller Stepping Down As President Of Warner Media’s Cartoon Network the premium video subscription service, Boomerang. She most recently was given responsibility of TCM.

Adult Swim continues to be the #1 network with young adults. Along with the success of award winning shows like Adventure Time, Rick and Morty, Steven Universe and global franchises, The Powerpuff Girls, and Ben 10, Miller has also gained a reputation as a thought leader on the topic of how to inspire kids to be the next generation of creators and innovators; and for the inspirational campaign, Stop Bullying Speak Up and partnerships with Dove, which have given kids the tools and resources needed for confidence and self-expression in their daily lives.

Prior to her current position, Miller was general manager of NBA Digital and SVP of Turner Sports Strategy/Marketing/Programming, where she led the day-to-day operations for the NBA Digital portfolio, managing relationships with league partners, as well as the strategic planning and scheduling of on-air sports programming and developing marketing programs for the division’s linear and digital properties. She joined Turner (WarnerMedia) in 2005 as VP, Cartoon Network Enterprises, where she was responsible for building the division’s first global consumer products business and after serving as senior vice president of brand management and licensing for HIT Entertainment.

Miller currently serves on the Boards of The Shed, Scratch and Hello Sunshine.

Read the original article on Deadline, here.