The executives said Chris Carlisle, FX's executive vice president of marketing and promotion, is likely to step into the job recently vacated by Roberta Mell.
Network executives declined comment late Friday.
Mr. Carlisle, a veteran of Warner Bros., Walt Disney Co.'s ABC and General Electric Co.'s NBC, has helped put FX on the TV map by taking a theatrical approach to marketing the cable network's aggressive original series such as Nip/Tuck and The Shield.
An outdoor campaign for the first season of The Shield used the stark tagline, "The road to justice is twisted," and a memorable photograph, shot by Mr. Carlisle himself, of series star Michael Chiklis. Mr. Carlisle also shepherded the Nip/Tuck campaign on-air and off-channel.
Ms. Mell, who opted out of the final year of her three-year Fox contract, left the network July 27. Her two-year tenure as executive vice president of marketing had given Fox a measure of stability in a job that had been a revolving door, with a prior marketing chief spending a few months there and the job sitting vacant for nearly two years after that.
During her watch, Ms. Mell helped launch hits such as American Idol, The Simple Life, and The OC. Her plans are unknown and she was not available for comment.
In addition to shaping the on-air look of the basic-cable network, Mr. Carlisle is credited with bringing high-impact feature film-style marketing to FX.