The president of entertainment at Fox, David Madden, is leaving the network, the company announced on Wednesday.

Mr. Madden will be replaced by Michael Thorn, a development executive at Fox’s in-house TV studio.

But Mr. Madden, a veteran of 21st Century Fox, may not be out of work for long. He was in advanced talks to become the new head of programming at AMC, according to a person familiar with the negotiations. In that position, he would occupy one of the most visible jobs in cable television, previously occupied by Joel Stillerman, who left AMC for Hulu this summer.

The job Mr. Madden was discussing would also include occupying a senior role at AMC’s in-house studio, said the person, who spoke anonymously to discuss private negotiations.

Mr. Thorn, meanwhile, will effectively be the new No. 2 at Fox, reporting to Dana Walden and Gary Newman, the co-chief executives of the Fox Television Group.

Though the network airs “Empire,” which was a hit in its first season, it has been in a prolonged slump. Earlier this year, Lachlan Murdoch, a top executive at 21st Century Fox, told investors that its performance has been “frustrating for us all.”