Four of the biggest entertainment companies in the world have bought or created television networks in recent years in order to pursue a simple strategy: They want to own both the programs and the source of distribution for them.

So it comes as something of a surprise in Hollywood that the No. 1 producer of new network shows for the upcoming fall TV season is a studio that doesn’t own a network.

The Columbia/TriStar Television Group, part of the Sony Corp., has eight new shows that will debut on various networks this fall, and three more that have been picked up as mid-season replacements.

It’s the first time Columbia/TriStar has ever led the pack in new shows, an area usually dominated by Warner Bros. Ironically, Warner Bros. had only four new shows picked up for next fall and six of its network shows from the past season have been dropped even though Warner’s parent company, Time Warner Inc., owns a television network (The WB, which didn’t pick up a single Warner Bros. show for next fall).

Despite the fact that many studios now own networks, television executives say the independent producers are in little danger of being shut out. For one thing, no matter who owns the network, it has to buy the best shows in order to remain competitive.

“Ultimately, it isn’t about owning the distribution apparatus, it’s about quality programming,” said Andy Kaplan, executive vice president of Columbia/TriStar Television.

Kaplan attributed his company’s success this year to a greater focus, saying Columbia/TriStar identified various needs at the networks and went after them. For example, the “Sleepwalkers” show it is producing for NBC was specifically developed to fit the network’s Saturday night schedule, when it will run in between two dramas with similar themes (“The Pretender” and “Profiler”).

But executives with other studios suggest there may be another reason for Columbia/TriStar’s success: Because its parent doesn’t own a network, it is more willing to make the kind of co-production deals that networks are now demanding.

In 1995, an important shift occurred in the TV industry when federal regulators repealed the so-called “financial interest and syndication” (better known as “fin-syn”) rules. The change meant that networks could for the first time own part or all of the programs they aired.

The result is that many networks particularly NBC and CBS, the only two of the six that aren’t owned by studios are beginning to insist on joint venture deals with the producers of their shows. Under co-production deals, the network retains a share of the syndication revenues that a show generates, and usually exercises some creative control over the program.

Four of Columbia/TriStar’s new shows involve co-production deals.

“The networks are afraid, in that their audience shares are eroding and have been for years, and their only income stream has been from advertising revenues,” said Christopher Barrett, president of Metropolitan Talent Agency, which packaged the upcoming comedy series “Veronica’s Closet” for NBC. “The advertising revenues may recede even further in the future, but the shows will continue to sell elsewhere (in syndication).”

Being independent of the networks may benefit Columbia/TriStar’s in other ways. Networks may be unwilling to buy shows from studios that own other networks with which they compete.

“There is a certain bias against enriching your nearest and dearest adversary,” Barrett said.

Despite a dearth of new shows, Warner Bros. remains the No. 1 one network television producer. With 11 shows from last season returning in the fall, the studio will have a total of 15 network shows, compared with 13 from Columbia/TriStar and 13 from Paramount Network Television.

But Warner Bros. was shut out at its own network, The WB even though the studio produced pilots for two ethnic sit-coms and a drama specifically developed for the network.

Warner Bros. officials weren’t available last week, but David Handelman, former general counsel at Fox Inc. and now of counsel with law firm Troy & Gould, explained that sometimes the production divisions of studios that own networks are actually at a disadvantage in selling shows to their own networks.

“If you buy a show from your own company, sometimes the feeling is that you may be doing somebody at the studio a favor but you’re not necessarily getting the best show,” Handelman said.

This phenomenon might help explain why not only Warner Bros., but Paramount and Walt Disney Co., had a relatively tough time selling shows to their own networks.

Disney, which owns ABC, has five new shows on the fall schedule all but one on ABC. But five Disney shows from last season have been canceled, two by its own network.

Paramount, whose parent Viacom Inc. owns half of the fledgling UPN, sold four new shows for next season, but four of last season’s shows were dropped. Only one new Paramount show, a co-production with Viacom-owned MTV Productions called “Hitz,” was picked up by UPN.

The exception to the rule is Fox. Five of the network’s eight new fall season shows come from Fox’s TV production arm, which was the second most successful producer of new shows after Columbia/TriStar. Fox has nine new shows on the fall schedule, with only three old shows being dropped.

One independent that took a blow this year is Studio City-based Carsey-Werner Co., which saw two of its shows (“Roseanne” and “Townies”) dropped by ABC while no new shows from the company will be added next season.

TV industry analysts, though, say Carsey-Werner is such a reliable supplier of successful shows that it’s likely to recover from the setback. The company has four returning shows.