WINSTON-SALEM, N.C. (AP) _ Anti-smoking activists are urging the federal government to regulate a high-tech, low-smoke cigarette developed by R.J. Reynolds Tobacco Co. that hits three U.S. cities for test-marketing soon.

''I'm not at all surprised that they announced the test-marketing,'' said John Banzhaf, executive director of Action on Smoking and Health, based in Washington, D.C. ''They wanted to get a jump on it. After all, it's a lot more difficult to get the genie back in the bottle after the fact.''

Reynolds Tobacco announced Tuesday that the new cigarette, which simulates smoking by heating a flavor capsule instead of burning tobacco, will be test- marketed in St. Louis, Phoenix and Tucson, Ariz., starting Oct. 1.

Reynolds, one of the nation's largest cigarette manufacturers and a subsidiary of Atlanta-based RJR Nabisco Inc., began selling the new brand, Premier, this week to distributors, supermarkets and discount chains in the cities.

While it will cost about 25 percent more - or about 30 cents a pack - than the company's other brands, Reynolds believes it could become its best-selling brand. The company will use a variety of messages, including one that touts the cigarette as ''Premier - the Cleaner Smoke.''

Banzhaf said about two dozen anti-smoking groups met with Food and Drug Administration officials recently to urge the agency to regulate the cigarette.

Joyce Taylor, branch director of the Arizona Lung Association in Tucson, said that if the FDA doesn't get involved, smokers won't know what they're inhaling.

''My theory is that regardless of what (company officials) are saying, if they're going to light it, they're still going to have carbon monoxide, which is one of the major irritants in smoke, and nicotine,'' she said.

''They're not telling us what's in that packet. They don't want the FDA to be involved, because then they would have to tell everybody what they put into tobacco smoke.''

Company officials, however, are not making any health claims, which could invite scrutiny by the FDA.

''If a product is sold with claims to make cigarettes safer, it is a medical device'' and subject to FDA approval, said William Grigg, an agency spokesman.

''This is not a safe or safer cigarette,'' said Richard Kampe, president of Reynolds' development divison. ''It's a cleaner cigarette.'' He said the term ''smokeless cigarette'' used by the media to describe the product is a misnomer.

The cigarette contains a packet of tobacco extracts that is heated, not burned, through a ''carbon heat source'' lit at the tip. The result is a cigarette without odor and only a trace of ash or smoke that could irritate people nearby, Kampe said.

''It reduces many of the controversial compounds associated with burning cigarettes and virtually eliminates sidestream smoke,'' he said.