Larry King, apparently unfulfilled by his daily CNN talk show, his daily Mutual radio show and his weekly USA Today column, comes to NBC this week with "Sunday Night with Larry King."

It's difficult to understand how King could fit the show into his schedule."I sometimes wonder myself," King said in a telephone interview. "Since I had my heart surgery, I really do have more endurance."

The host said the idea for the show wasn't his.

"It was a shot out of the blue," King said. "(NBC Entertainment Chairman) Brandon Tartikoff called and said, `Would you be interested in hosting a variety show.'

"I wasn't at the time. I'd just signed a new (five-year) contract with CNN and, with the radio show too, I didn't think I'd have the time."

But Tartikoff was persistent. And when CNN chief Ted Turner agreed to let King give it a try, King finally said OK.

Billed as an "information and entertainment television event" and perceived as a successor to the old `Ed Sullivan Show,' the program will feature everything from King interviewing Bart Simpson to a reunion of the cast of "Rocky."

"We want to show you what variety was on television," King said. "A lot of people don't know `The Ed Sullivan Show,' it's been off the air so long."

Other scheduled guests include comedy bits by Garry Shandling and David Letterman, musical numbers by the Teenage Mutant Ninja Turtles, rappers DJ Jazzy & The Fresh Prince and country singer Kathy Mattea, a wild-animal act by Siegfried and Roy and an interview with Donald Trump.

King has no illusions about himself as a performer.

"I know how to host, how to ask questions. I'm glib," he said. "I know my way around a mike and a camera. I'm no entertainer, but then neither was Sullivan."

If the show is a hit - "and that's a big if - we'll just present it and see how it is received . . . " - don't expect to see King as a weekly fixture on NBC.

"I couldn't do it on a weekly basis," he said. "Unless we did it like three times a year, I just can't do it."