SCENE OUTSIDE `SEINFELD' SET YIELDS LOT OF NOTHING.

Byline: Keith Marder Daily News Television Writer

Electronic and print reporters set up camp outside the CBS Studio Center on Wednesday, covering perhaps the greatest nonstory of the decade.

They pounced on every morsel of information, every glimpse of a cast member they could spy to feed flimsy stories about the filming of the final ``Seinfeld'' episode. It got so bad during the daylong stakeout, bored news crews started interviewing each other and even ended up falling for a fellow journalist's prank.

The hype has been building like lines for lottery tickets over the last few days, as secrecy shrouded nearly every detail about the finale of one of the most popular television series of all time, scheduled to air May 14. Since December, when Jerry Seinfeld announced he would turn down $5 million an episode to return for a 10th season, there has been speculation about the last show and the future of NBC's Thursday night ratings reign.

But the tight-lipped cast and crew left journalists floundering.

Chuck Whitlock of ``Extra'' came up with the best story at the expense of the pack. He posed as a prop master, setting up a folding table outside the studio gates to sell what he claimed were signed cereal boxes that actually appeared on the show. Bored reporters bid in excess of $20 for the cereal.

Whitlock then produced two tickets for the final taping of the show, getting $40 for what he would later confess were fakes - just like the cereal boxes.

He eventually returned all the money, explaining that the scam was for an ``Extra'' segment called ``Cons on Camera.''

Red-faced reporters returned the breakfast food for their cash. But the local NBC affiliate apparently missed the scam revelation, airing a news segment that mentioned the cereal sale, not realizing it was a hoax.

CNN, which at one time had all three entrances to the studio covered with separate crews, got there first at about 9 a.m., recording series star and co-creator Jerry Seinfeld cruising through the gates in his silver Porsche Boxster and Michael (Kramer) Richards pulling in behind the wheel of a black Mercedes sedan.

And Dana Adams, who flew in from New York to report for CBS, won for best effort Wednesday. Flashing her network credential, she was escorted onto the lot but had to leave her camera operator and microphone behind. She emerged moments later with no story, but three souvenir hats from the studio.