EXCLUSIVE: Fox’s No.2 programming executive Matt Cherniss will be leaving the network and the TV business. I hear he is in negotiations with Warner Bros. for a job on the feature side. This would mark Cherniss’ first stint outside of Fox family where he has spent his entire career so far with tenures at Fox and FX.

Fox is not expected to fill the position, EVP of programming, whose previous holders include Robert Greenblatt, David Nevins and Craig Erwich. Cherniss was brought in by Fox Entertainment president Kevin Reilly and former chairman Peter Liguori in May 2008 as Reilly was in the early stages of building his development team. Now I hear Fox is eyeing a structure with fewer layers, with department executives expected to get more responsibilities.

I hear it was Cherniss’ desire to pursue a move to features and that his bosses Rice and Reilly are supportive of his decision. Cherniss has a long-standing relationship with Reilly for whom he worked at Fox and at FX. For the past 2 years, Cherniss oversaw drama and comedy development and has had major hand in the development of such Fox series as Glee and Raising Hope. Before joining Fox, he served as SVP of original programming at FX where he shepherded development of such series as Damages and Sons of Anarchy. And before joining FX in 2002 as director of drama and comedy development, he worked at Fox as an associate in the Program and Network Research Group and then director of current programming.