President of Fox TV Resigning : Networks: Lucie Salhany, Twentieth Television chairman, may succeed Jamie Kellner.

Jamie Kellner, who helped turn Fox Broadcasting Co. into a viable fourth network, said Monday that he is resigning as president to start his own business, possibly in association with Fox Inc. Chairman Rupert Murdoch.

Murdoch is expected to name as Kellner’s successor Lucie Salhany, chairman of Twentieth Television, the syndication and network program production arm of the Fox studio, a knowledgeable source said. Salhany, a former Paramount Pictures TV executive, helped develop and produce Paramount’s hit syndicated late-night program “The Arsenio Hall Show.”

Kellner’s departure comes just as Fox is preparing to launch a long-awaited seventh night of programming. But people close to the network say they do not expect it to affect Fox’s plans.

Kellner was one of the Fox executives who helped make a rickety string of UHF affiliates into a significant competitor to ABC, CBS and NBC through a combination of innovative programs such as “The Simpsons” and low-brow shows such as “Married With Children.”

There has been widespread executive turnover at the film and TV studio since Murdoch took direct command last year, following the resignation of Fox Inc. Chairman Barry Diller.

Last month, Peter Chernin, the network’s chief programmer, was named chairman of 20th Century Fox Film Corp., succeeding departing film studio boss Joe Roth. Murdoch promoted Sandy Grushow, a marketing and promotion executive, to head of programming.

Kellner, 45, said he originally wanted to step down a year ago, but Diller’s sudden departure forced him to postpone his plans.

“I reached my objective, and now I want to move on,” Kellner said. “I’m going to take a little bit of a breather and then decide.” Kellner, who has also been appointed to the Fox Inc. board, said he might start up a new media-oriented business with backing from Murdoch.

Kellner’s successor is a veteran TV executive from the rough-and-tumble but immensely profitable syndication business.

One of only a handful of women in Hollywood who occupy a power position at a studio, Salhany provoked a controversy last year when she pulled the plug on ABC’s “Anything but Love,” starring Jamie Lee Curtis and Richard Lewis, because she determined there was not enough profit in its future reruns to justify the show’s weekly production costs.

Although frequently overshadowed by his high-profile bosses, Kellner was the Fox executive who forged and maintained relations with Fox affiliates and advertisers during the crucial early days of the network.

“Jamie made Fox a viable medium,” said Jon Mandel, senior vice president of Grey Advertising. “That’s why who they replace him with is critical to the advertising community.”

The 7-year-old Fox network has posted steadily improving profits in recent years despite an overall downturn in TV advertising. In the last fiscal year, Fox earned about $53 million in operating profit on about $520 million in revenue. Revenue and profit are expected to increase significantly again this year.

After several setbacks, Fox will finally expand to a seventh night of programming Jan. 19, with two hourlong dramas, “The Class of ‘96” and “Key West.”

Federal regulations prohibit Fox from regularly airing more than 15 hours of prime-time programming per week as long as it continues to syndicate shows such as “Studs” and “America’s Most Wanted.”

Although the network won a six-month waiver to comply with “financial interest and syndication” rules, it is not expected to reach the 15-hour limit for a couple of years.

In the nearer term, the new Fox president will have to mollify affiliates, who are expressing concern about Fox’s upcoming late-night talk show starring Chevy Chase. The show, produced in-house by 20th Television, is slated to go on the air next fall.

The Chevy Chase gamble comes at a time when the late-night talk show scene is highly unstable, with NBC’s David Letterman entertaining a generous offer from CBS that would also place him opposite Arsenio Hall in many markets. Fox made an offer for Letterman last month in the hopes of creating a two-hour “late prime” block of programming, but the late-night talk show star believed that the fourth network did not offer him enough exposure.