An obscure federal agency is about to create a revolution in the frozen pizza world by proposing regulations that would dictate the minimum amount of cheese in each pie.

The Food Safety and Quality Service also wants pizza makers to spell out -- in bold letters on the package label -- if they use artificial cheese or skimp on the beef or sausage topping. l

If the proposed rule goes through, one official said, supermarket shelves could soon be graced with something called "Uncles Charlies's Pizza Made With 3 Percent Cooked Sausage, Cheese Substitute and Cheese."

"That would be the absolute worst case," said Dr. David Shenkenberg, a food science expert now drafting the so-called pizza standard. "That would be the real economy model."

The pizza standard, which both Shenkenberg and industry officials say would have far-reaching implications for the food industry, has been announced only in a tiny notice in the Federal Register which said that a formal proposal would be made Dec. 15 and final action could be expected next May.

But it is already sending shock waves through the frozen-pizza industry, pitting artificial cheese advocates against dairymen and pizza maker against pizza maker.

"The rule may be delayed by politics and the change of administrations. But sooner or later, the pizza industry will have to face this issue," said a spokeswoman for the National Frozen Pizza Institute, the trade association for the more than $400-million-a-year industry that is relying increasingly on cheap artificial cheese.

The food safety and quality agency, an arm of the Agriculture Department charged with ensuring truthful labeling of packaged foods containing meat or poultry, currently sets minimum limits only on the meat on top of the frozen pies. Pepperoni pizza, for example, must be at least 10 percent pepperoni, and chili pizza at least one-quarter chili.

But the growing popularity of imitation cheese, and the resulting outcry from dairy interests, is forcing agency officials to go deeper: into the cheese.

Shenkenberg said the three-part pizza standard, still being polished, would:

Require packaged pizza sold in interstate commerce to contain not less than 6 percent real cheese. Shenkenberg noted that there are "lots of pizzas on the market where what is perceived as cheese is 96 percent artificial."

Allow pizza makers to use less meat topping if they reveal the shortfall in the name. Sausage-short pizza, for instance, could be named, "Pizza With 3 Percent Sausage."

Make manufacturers of any meat or poultry product containing artificial cheese say so in the name. Frozen cheeseburgers containing artificial cheese would become "Cheeseburgers Made With Cheese Substitute," Shenkenberg explained.

Cheese makers are divided over the proposed regulations.

"I have mixed emotions," said Robert Anderson, executive director of the National Cheese Institute, noting that many real cheese producers make ersatz cheese as well.

Anderson said that artificial cheese, which may include soy protein and chemical emulsifiers and stabilizers as well as milk extracts, is generally as nutritious and safe as real cheese. It is also less expensive, which benefits producers as well as consumers, he said.