On the heels of a realignment of the top brass overseeing Sony’s TV operations, Jon Feltheimer has resigned after a four-year run as prexy of the Columbia TriStar TV Group.

Feltheimer’s departure from the studio had been expected in the wake of Mel Harris’ return to the Sony lot as co-prexy and chief operating officer overseeing TV (Daily Variety, Sept. 10). Harris was Sony’s TV topper from 1992 to 1995, when most of his responsibilities were assumed by Feltheimer.

Feltheimer, who was also exec VP of Sony Pictures Entertainment, had been with the studio since 1991. He came over as prexy of the then-separate TriStar TV banner with a team of execs from New World Television after Sony acquired New World’s TV assets.

It’s unclear whether Feltheimer will be replaced. Harris is set to begin his new job today, and a Sony rep said Harris would have to evaluate the situation before any decision was made.

Feltheimer had been in negotiations for the past several months to renew his employment contract, which was up early next year. It’s understood that he was looking to move up the Sony Pictures management ladder, and when it became clear that the two sides were at impasse, the studio moved to recruit Harris.

Howard Stringer, chairman and CEO of Sony Corp. of America, praised Feltheimer for having reinforced the company’s “global television strategy and developed a powerful television infrastructure.”

But Sony insiders said Feltheimer was viewed as something of a maverick within the tightly run, Tokyo-based conglom. Some said Feltheimer had failed to keep top brass totally abreast of major deals he was orchestrating, but others disputed that notion, citing the iron-clad regular weekly sked of management meetings.

Feltheimer, known to many as “Felt,” is well-liked and well-connected in TV circles. He spent eight years with New World, building its TV operation from the ground up before moving to Sony in 1991. Before that, he was a partner in the Feltheimer/Knofsky management banner and also worked as an investment banker.

“Jon Feltheimer is clearly one of the best television execs there is,” said CBS Television topper Leslie Moonves. “He will be sorely missed at Sony. He provided us with a number of terrific programs and was always a stand-up guy to do business with.”

During Feltheimer’s tenure, Columbia TriStar TV developed such hits as “Mad About You,” “The Nanny,” “Party of Five” and “Dawson’s Creek.” He also steered the TV studio’s expansion into animated, interactive and online entertainment ventures.

Moreover, Sony markedly increased its level of international TV production over the past few years while launching or investing in more than two dozen TV channels around the world.

Most recently, Feltheimer put together complex distribution deals for Sony with Brad Grey’s new BGTV banner and Artists Television Group — the Artists Management Group-affiliated production venture launched earlier this year by a handful of former Col TriStar TV execs.

Feltheimer was also the driving force behind Sony’s acquisition, along with Liberty Media, of the Spanish-lingo web Telemundo last year.

Sources said that web’s troubled management was viewed from above as a strike against Feltheimer, even though Telemundo had been in dire straits long before Sony came into the picture. The first Sony-appointed head of Telemundo, former CBS exec Peter Tortorici, was replaced in July by international TV vet Jim McNamara.

Looking ahead, Feltheimer said the next chapter of his showbiz career would involve something “entrepreneurial” that would afford him an ownership interest.

“The kind of reaction I’ve had from friends and colleagues today makes me feel very optimistic about our business,” Feltheimer said. “Those who have been my partners here at Sony over the last eight years will go on and continue building what we’ve started. It should only be enhanced by Mel’s arrival.”

(Josef Adalian contributed to this report.)