Television: The production exec who was brought in as his boss in the fall will take on the job until the fourth-place network names a successor.

     Doug Herzog stepped down Wednesday as president of entertainment at Fox Broadcasting Co., ending a tumultuous 15-month tenure during which the television network plunged in the ratings and was restructured.
     Herzog is the latest in a string of executives who have held the head entertainment job at Fox, whose history of turnover every two years has frustrated many program suppliers eager for continuity and stability.
     Fox does not expect to name a successor until summer. In the meantime, the job will be done by Sandy Grushow, the TV production chief who was brought in over Herzog last fall, two months into the new season.
     Hollywood television executives have speculated for weeks that Gail Berman, president of Regency Television, has already been approached about taking Herzog's position.
     Regency and Fox Television Studios have a 50-50 co-production deal and produce the comedy "Malcolm in the Middle," the only new program on Fox that shows promise.
     Herzog's departure, which was expected, underscores the difficulty of entering Hollywood as an outsider.
     Television executives say the cable executive's lack of understanding of the broadcasting business and of network television ultimately undermined his staying power.
     Others, however, say Fox's parent company, News Corp., didn't give Herzog enough time to make his mark and point to a recent rebound in the ratings and the success this week of another new comedy, "Titus," which was the network's highest-rated premiere ever on a Monday night.
     Herzog was recruited with great fanfare in late 1998 and was billed as the network's best hope for bringing live-action comedies to Fox, whose success was built on irreverent animation such as "The Simpsons" and dramas such as "The X-Files."
     Herzog had made a name for himself as the head of Comedy Central, which broke cable ratings records by airing the blockbuster "South Park."
     Coming into last fall, Fox was second in the ratings, with a clear shot at edging out NBC for the top spot. But eight weeks into the season, ratings in key young demographics had fallen 19%, with the network still mired in fourth place despite a rebound that has closed the year-over-year decline to 9%.
     Although many of the problems took root before Herzog's January 1999 arrival, News Corp.'s top executives grew nervous that his lack of experience would slow a turnaround.
     Although one of Herzog's mandates was to rein in programming costs, using his experience in the low-budget cable business, agents in town balked and some began bad-mouthing the new Fox executive.
     Herzog's inexperience was also off-putting to some producers and suppliers.
     With the network in a shambles, Peter Chernin, president of News Corp., named Grushow chairman of the newly created Fox Television Entertainment, which brought 20th Century Fox Television studio and the Fox network under one umbrella.
     But the attempt to arrest the network's slide by bringing in a new boss didn't sit well with Herzog. Grushow began taking meetings with agents and took control of many responsibilities that had been Herzog's alone.
     Sources say Herzog, who uprooted his family from New York and bought Roseanne's house in Brentwood for $3.1 million, has been negotiating an exit package for weeks and may remain on the West Coast.
     They say he is undecided about his future, although sources say he has been approached by several "dot-coms," including Pop.com and Macromedia's Shockwave.