Wrestling is about to face a major rival in the TV ring.

With ratings beginning to hit the mat, producers are looking for a successor to take wrestling’s place and become the next cultural phenomenon that appeals to the lucrative demo of fight-loving 18- to 34-year-old males.

And they think they’ve found it: mixed martial arts.

The sport, which combines karate, judo, jiujitsu, tae kwon do, kung fu and boxing, among other fighting techniques, only trails soccer as the most popular sport in the world. Its events fill stadiums and attract an impressive number of television auds.

However, the sport has yet to go mainstream among U.S. TV viewers. That’s because, outside of the occasional pay-per-view fight, little programming exists that capitalizes on the appeal of the sport.

A martial-arts fight club of players is trying to change that, recruiting high-profile showrunners to weekly formats (i.e., competitive reality concepts) and is shopping to the broadcast and cable webs.

Among them:

  • Former William Morris agent Xavier Kochhar last week announced he has formed XK Entertainment with plans to develop series revolving around 10 of the world’s largest mixed martial arts orgs, including U.K.’s World Boxing Federation, Italy’s World Assn. of Kickboxing and Canada’s Ultimate Combat Championships.

  • “Survivor” supremo Mark Burnett has teamed with sports production-management outfit Battle Entertainment to create a reality franchise for the small screen that involves Japan’s K-1, considered the NFL of mixed martial arts.

  • Producer Larry Kasanoff (“Mortal Kombat”) is trying to launch a 24-hour cable channel called Blackbelt TV, which will broadcast movies, such as Bruce Lee’s “Enter the Dragon,” TV shows, such as “Kung Fu” and events.

  • Reality program producer LMNO Prods. has teamed with Ultimate Fighting Championship on an overall development deal designed to bring the once-controversial franchise to TV.

Similar to how the World Wrestling Federation (now World Wrestling Entertainment) created shows such as “Raw” and “Smackdown” around its bouts, the latest batch of producers is also teaming with major fight orgs and the superstar athletes they’re associated with.

Not only is the strategy expected to give their projects more credibility when pitching to network execs, but it guarantees them a built-in audience, especially for fans of specific athletes, and additional revenue streams.

Burnett and Battle’s partner K-1, for example, attracts an average of about 70,000 to 90,000 fans to its live events in Japan as well as one-third of the country’s TV viewers.

Besides money generated from pay-per-view bouts, the company’s created a cash cow in licensing and merchandising, selling homevids, vidgames, clothing, etc.

“These sports organizations have huge draws and ticket sales to their events,” Kochhar says. “We’re saying: Let’s create a show, attach the organization as a backbone, find a great showrunner and take the whole package to a network.

“But even better we’re ensuring networks something more than just ratings,” he says. “What made ‘American Idol’ so great wasn’t the show itself, but the scalability of the show. When the show was over, there was a CD and tour. They have a company whose business it is to do that. We have the same thing.”

Once the biggest draw on cable, wrestling became a ratings powerhouse that helped put UPN and cablers USA and TNN on the map.

But viewership is on a decline. Not one primetime-wrestling hour showed up among the 10 highest-rated individual programs in households on cable over the summer. Meanwhile, attendance at live wrestling events fell by 40%, while PPV buys also dropped by 40% during the WWE’s most recent quarter.

Producers say the timing’s right for television to adopt martial arts in a major way, not just because of auds’ growing disinterest in wrestling, but also the sport’s growth in the U.S.

Elements of the sport already have taken over what Americans do during their free time, with nearly 16 million people practicing some sort of martial art. More kids take martial arts classes at one of the country’s 25,000 schools than compete in Little League. Tae-Bo videos are still big sellers. And you won’t find too many gyms without a kickboxing class.

The martial arts phenom has already crossed over to film, with nearly every action movie hitting theaters featuring their heroes, even “Spider-Man,” throwing karate chops.

“The feature film business has already figured it out,” Kochhar says. ” ‘The Matrix’ made it cool, and now there isn’t an action movie out there that doesn’t have one form of martial arts in it. But there isn’t anybody in TV that’s been able to crack the nut.