Leave it to the company that makes the Uncola to do something uncommon and unconventional.

When most companies put together a new advertising blitz, they get their ad agencies to come up with a new image, a new slogan and a new batch of commercials. But Seven-Up is reaching back into its past.

The company is reviving its famous "Uncola" campaign, last seen 10 years ago, and has even rehired spokesman Geoffrey Holder, whose mellifluous reading of the words "cola nuts" helped make the Uncola campaign a classic.

"If the identity is there, why walk away from it?" Seven-Up President Edward W. Frantel said yesterday.

"It is unusual," said Emanuel Goldman, a beverage-industry analyst at Montgomery Securities in San Francisco. "You usually don't see companies going back to prior campaigns."

Seven-Up is probably willing to try just about anything. Its share of the nation's soft drink market has slipped to 5.1 percent from 5.4 percent a year ago, according to Goldman, and it is light years behind market leader Coca-Cola, which commands a powerful 24 percent share.

Seven-Up isn't even in its traditional spot of third place any more -- Diet Coke, introduced a little over two years ago, "blew right by them like an Olympic runner," as Goldman puts it, dropping Seven-Up into the No. 4 spot. In addition, the beverage is feeling pressure from other lemon-lime drinks, such as Coca-Cola's Sprite.

The Uncola campaign, which first debuted 17 years ago, ran in various forms for several years before disappearing entirely. But consumers didn't forget it. The company found that when it did consumer surveys, a vast majority of those responding related Seven-Up to the Uncola nickname. "The awareness is tremendous," said Frantel, who was brought in to run Seven-Up by its parent company, Phillip Morris Inc.

The latest campaign features a new series of television ads starring the seemingly ageless Holder, a Broadway actor and choreographer. In each, he extols the virtues of Seven-Up and ends with the tagline "The Uncola. Ahhhhh." Some ads also add a new chapter in Seven-Up's long-running "No caffeine, no artificial colors or flavors" theme -- the drink is now touted as having no preservatives.

Frantel says the size of the campaign is unprecedented for the company. He wouldn't give any figures, but he said it will begin with a five-week "intro-blast" that will jam the equivalent of several months worth of advertising onto the nation's airwaves and into newspapers and magazines.

Goldman said that Seven-Up needs to reestablish itself in light of all the publicity Coke and Pepsi have gotten in the past couple of years with campaigns featuring Michael Jackson and Lionel Richie (for Coke) and Geraldine Ferraro (for Pepsi) as well as the introduction of such products as Diet Coke.

"There's an enormous emphasis on colas -- Diet Coke, Diet Pepsi, cola, cola cola," Goldman said. "I can see why they're doing it."