The hit zombie drama series "The Walking Dead" has been renewed by AMC for a fourth season, but showrunner Glen Mazzara is not returning.
The cable channel announced the news in a statement obtained by OTRC.com on Friday, December 21.
"Today, AMC announces the season 4 pick-up of 'The Walking Dead,'" the cable channel said in a joint statement with Mazzara. "AMC also jointly announces with Glen Mazzara today that for future seasons, the two parties have mutually decided to part ways."
"AMC is grateful for his hard work," the statement said. "We are both proud of our shared success. Both parties acknowledge that there is a difference of opinion about where the show should go moving forward, and conclude that it is best to part ways. This decision is amicable and Glen will remain on for post-production on season 3B as showrunner and executive producer."
Mazzara took over show creator Frank Darabont's position as showrunner during the second and current third season, which featured newcomer Danai Gurira of "Treme" fame as Michonne. The series also stars Andrew Lincoln, Jon Bernthal, Sarah Wayne Callies, Steven Yeun and Laurie Holden.
"I've had an amazing experience as showrunner for S3 @WalkingDead_AMC but it's time to move on. Thank you to all the fans for their support," Mazzara Tweeted on Friday. "The #WalkingDead fans are absolutely amazing. I cannot thank you enough for your support. Thank you to an immensely talented cast and crew."
The mid-season finale of "The Walking Dead" aired on December 2. More than 10.4 million people watched the episode, which was the top-rated cable show that night, with a rating of 5.4 among adults between ages 18 and 49 -- which is considered impressive for a network series, let alone a cable show.
The third season resumes on February 10. The fourth cycle is expected to begin in the fall of 2013.