Jason Alexander, who plays Jerry's obnoxious best friend George on "Seinfeld," said he owes his career to none other than Capt. James T. Kirk of the starship Enterprise.

"I know it sounds like a joke. I became an actor because I wanted to be William Shatner commanding the Enterprise," Alexander said. "And before I had any training or lessons or anything, I would basically do William Shatner."A rather odd choice, because despite his great success on "Star Trek" Shatner isn't generally recognized as one of the world's finest acting talents. But that didn't stop Alexander from imitating Shat-ner's staccato delivery.

"I just thought if you - broke - sentences down - that you could play any - role," he said, mimicking Shatner. "It worked for many years. I did Shakespeare as William Shatner. I once played Nathan Detroit in `Guys and Dolls' as William Shatner.

"Who knew? I thought that was great acting."

There's no mistaking George for Kirk, however. George is at once grating and lovable as an out-of-work loser.

"I always thought on the evolutionary scale, George was kind of low. But, apparently, everyone knows one, and I'm delighted," Alexander said. "You know, it's wonderful that he's been so embraced, as opposed to people going, `I'd rather not have him in my house.'

"People come up and go, `You remind me of me,' and I have such pity for them," he added. "And I say, `Oh, please, see someone. And get a life."

"Seinfeld" is not Alexander's first sitcom. He had a supporting role in the short-lived "E/R" in 1984-85, and in 1987 he played one of two mismatched brothers in the CBS show "Everything's Relative," which lasted a month.

"That show, we thought, was your average run-of-the-mill television sitcom. We didn't really think we were going to stink quite as badly as we did," Alexander said. "We actually thought, `This is the kind of show that very easily runs for nine years.

"With this show (`Seinfeld'), from the moment I saw the script I thought it would be the most brilliant thing I'd ever be part of, and that it would not run for even a day. Because the audience for this show is me, and I don't watch TV."

Except, of course, for "Star Trek."

"But I don't think anyone is more surprised by the success of (`Seinfeld') than we are, because we thought, `Oh, we'll amuse ourselves, and that'll be it. We'll have a videotape at the end of it that we could play at parties.' "

"Seinfeld" has always been a curious mix of reality and fantasy. Standup comic Jerry Seinfeld plays a standup comic named Jerry Seinfeld on the show.

And that odd dichotomy will become even odder this fall when a continuing story line is introduced.

"The idea is that NBC is going to become interested in me to have my own TV series," Seinfeld said. "And George and I are going to write it."

Apparently, George still isn't going to find a real job.

"Well, with the NBC deal, he's going to be able to get some money out of that - if he doesn't blow it. I can tell you, he's not doing too well at the moment.

"At this point, George has taken over the negotiations without telling me and has found himself in (NBC Entertainment President) Warren Littlefield's apartment during a romantic dinner and, well, it goes on from there," Seinfeld said.

But tonight's season premiere (8 p.m., Ch. 2) picks up where last season left off - Kramer is in Hollywood, where he's just made an appearance on "Murphy Brown." (This gets odder and odder.)

In the first of a two-parter, Jerry and George head for Los Angeles, where they run into Corbin Bernsen ("L.A. Law"), George Wendt ("Cheers") and a "surprise guest."

It's yet another example of how "Seinfeld" has turned out to be one of the best comedies on TV.