EXCLUSIVE: Russell Hicks, an 18-year Nickelodeon veteran, has stepped down as President, Content Development and Production for the Nickelodeon Group. I hear his resignation, which is expected to be announced internally tomorrow, came soon after he’d returned from a four-month medical leave. There are no plans for him to be replaced at this time.

“Russell Hicks has decided to step down from his position effective immediately,” a rep for Nickelodeon confirmed to Deadline, declining further comment.

Hicks oversaw the live-action, animation development and production teams for all of Nickelodeon’s content platforms and across all of the network’s channels—Nickelodeon, Nick at Nite, Nick Jr., TeenNick and Nicktoons. Yet, he has maintained a relatively low profile. There also had been rumors that he may not have always seen eye to eye with long-time Nickelodeon chief Cyma Zarghami who a year ago was promoted to oversee Viacom’s newly formed kids and family group that includes the Nick brands.

Nickelodeon upfront
Jeremy Gerard

I hear in her internal memo Zarghami speaks highly of her lengthy partnership with Hicks and praises him for shepherding the Nickelodeon development team to deliver some of the network’s biggest recent successes.

Hicks’ exit comes as Nickelodeon has started to climb back in the ratings after a period of declines. Nickelodeon returned to No.1 in kids 2-11 last year, claiming the top 3 shows in the demo with Alvinnn!!! and the Chipmunks, The Loud House and veteran SpongeBob SquarePants.

While the rest of the Viacom networks, including MTV, VH1, TV Land and Comedy Central, underwent top executive shakeups following last year’s restructuring of the network group under Zarghami and Doug Herzog, Nickelodeon has remained pretty stable.

Among Hicks’ initiatives at Nick, he started an animation shorts program to attract new talent and projects. In live-action, he opened a sketch lab in Los Angeles, creating comedy workshops to cultivate new talent.

Before being named president of the Nickelodeon Group in 2012, moving to the West Coast, Hicks served as Nick’s Chief Creative Officer. In this position he oversaw all of Nickelodeon Creative, On-Air Promotions, Consumer Products, Brand and Advertising divisions, and led the product development and creative positioning of Nickelodeon’s brands and properties.

Prior to working at Nickelodeon, Hicks was VP Marketing, Cartoon Network/Turner brands for Warner Brothers.