Jay, Arsenio . . . and Ted? You Bet . . .

Everybody talks about Jay and Arsenio, or Arsenio and Jay, when it comes to late-night TV dominance.

But there is, lest we forget, another prominent guy out there butting heads with NBC’s top-rated “Tonight Show” host Jay Leno and the syndicated comedian Arsenio Hall.

“And I’m funnier than both of them,” quips the third contender, Ted Koppel of ABC’s “Nightline” series.

Amid all the talk of who’s going to be No. 1 in the late-night ratings now that Johnny Carson has retired from “Tonight,” it may surprise some viewers to know that Koppel thinks he has a good shot at it.

He’s not kidding.

Like the other contenders lining up to try to wrest leadership away from “Tonight,” ABC sees Carson’s departure as “a window of opportunity” for Koppel and “Nightline,” says a spokeswoman for the network.

Leno, however, has delighted NBC with his ratings performance in his first month as Carson’s heir, retaining the top spot and registering strongly with viewers desirable to advertisers--audiences ranging in age from 18 to 34, 18 to 49 and 25 to 54.

But the startling thing is that “Nightline” for years has been a solid No. 2 to “Tonight”--even beating it on occasion--although it gets live clearances from its affiliate stations in only 63% of the nation, while the rest of the country sees it later than its regular time period.

Just last Tuesday, “Nightline” flexed its muscles again when a program with Caspar Weinberger, the former Reagan Administration defense secretary indicted in connection with the Iran-Contra affair, beat both “Tonight” and a Hall show with Madonna in the big-city ratings.

But Koppel’s dilemma remains. In a phone interview from his Washington office Thursday night, the newsman elaborated on the recent message that he and ABC News President Roone Arledge delivered to their affiliates--that station support will determine the fate of the series and whether it survives.

“The program in a sense is at one of the most interesting crossroads it’s ever faced,” said Koppel. “If we can only get half a dozen significant stations that are now delaying the broadcast to carry it live, ‘Nightline’ would be No. 1. It’s only behind ‘The Tonight Show.’ It beats everybody else that’s out there.

“By the same token, if another half a dozen or so stations were to go from live clearance to a delayed broadcast, we’re going to begin approaching the point at which the network inevitably will start coming to us and saying: ‘Well, maybe you can cut back a little on use of satellites. Maybe you shouldn’t be making trips. Maybe you shouldn’t be doing the longer investigative reports.’

“And the only point I was making--and I’ve made it to my bosses--is that that’s not the kind of ‘Nightline’ that I wanted to be associated with.”

In other words, he would leave the distinguished series that he has made a TV institution?

“That’s right.”

According to ABC, “Nightline” now gets live clearance on 119 stations that penetrate 63% of America. The series is delayed on 105 stations that cover the remainder of the nation. (Although “Nightline” is seen on a tape-delayed basis in Los Angeles, it is considered a live clearance because it is carried in ABC’s regular program sequence.)

According to Koppel, two of the significant markets he covets and would like to see return to live clearance of “Nightline” are Dallas and Atlanta: “If major stations (like these) were to make that commitment, I think it would send a message throughout the whole industry.”

Added Koppel: “We’re on the brink of doing what ABC has dreamed of for 30 years (during Carson’s reign), and that is dominating the 11:30 time period. We’re doing better in the ratings than we have done in years.

“We’re doing remarkably well considering that we only have 63% live clearance. To give you a for instance, during two of the last four weeks that Carson was on ‘The Tonight Show,’ ‘Nightline’ won the week.”

One of those weeks included the Rodney G. King verdict and the Los Angeles riots, and “Nightline” is always at its strongest during major news stories.

Despite the strength of “Nightline,” Broadcasting magazine reports that Stephen Weiswasser, executive vice president of ABC News, “said with rising production costs ABC would reach a point where it could no longer afford to keep the show without better (station) coverage.”

Most of the stations that delay “Nightline,” said Koppel, “take syndicated programs like ‘MASH’ and ‘Maude.’ It’s a simple economic decision, and I understand the economics. You know, they get the full 6, 6 1/2 minutes worth of commercials if they buy a program, and they only get 2 1/2 minutes worth of commercials if they take ‘Nightline’ (from ABC).”

Sitcom reruns also often get bigger ratings than news shows like “Nightline,” which means that stations can charge higher prices for commercials.

The way Koppel sees it, the live clearance problem could affect NBC as well: “The great fear that the folks at NBC have is that if the Leno program doesn’t do extremely well between now and November, they too will start losing (clearances). That’s still a reflection of the enormous clout that Johnny Carson had.

“Jay Leno is an enormously talented man, and I have no doubt that he will do very well. But there’s no question that NBC affiliates are looking at the same economic realities as ABC affiliates, and the same kind of thing could happen. I think it’s shortsighted on all their parts because there are very few signature programs anywhere anymore that last year after year after year.

“You’ve got programs like ‘Good Morning America,’ ‘Today,’ ‘60 Minutes,’ ‘The Tonight Show.’ If you let those go, it’s almost impossible to re-establish a signature show. I’m not talking about a show that lasts five or six seasons. I’m talking about a show that can last 20 seasons.”

At the moment, “Tonight” and “Nightline” are well ahead of Hall. The Dennis Miller series is way back and CBS’ action lineup, “Crime Time After Prime Time,” has picked up a bit in the ratings but continues to trail Leno and Koppel.

Asked about the reports that NBC’s David Letterman might jump to ABC when his contract is up next year, Koppel said his understanding was that no moves were currently being made, but that if anything developed, “it would not be with an eye to putting him on at 11:30.”

Would Koppel like to have “Nightline” and Letterman go back-to-back on ABC?

“I’d be thrilled. I’m one of his greatest fans. It’s a terrific program.”

Meanwhile, Leno and Letterman are clicking as a ratings tandem, and NBC is going all out to make sure the successful pairing remains intact.