R.J. Reynolds Tobacco Co. yesterday stopped test-marketing its controversial smokeless cigarette, bringing to an abrupt halt a well-publicized new product gamble that may have cost the tobacco giant half a billion dollars over the past five years. The decision follows disappointing sales of the smokeless cigarette -- called Premier -- since it was introduced in test markets in Arizona and Missouri last October, and came amid mounting opposition to the cigarette from public health groups, which claimed that it presented unknown safety risks to smokers and should have been reviewed by federal health officials before being sold to the public. However, the company left the door open for a possible introduction of a similar product as Reynolds, like the rest of the tobacco industry, continues to look for ways to stem the decline in U.S. cigarette consumption. Reynolds, a Winston-Salem, N.C.-based division of Atlanta conglomerate RJR Nabisco Inc., said it would consider returning the product to the market if it could "fully address the issues raised in the test markets... . We intend to continue developing new technologies that will better meet consumer demands." "This isn't the end of smokeless cigarettes, it's simply a delay," said Diana Temple, an analyst with Salomon Bros. in New York. "Because this product is so revolutionary, it's still very early in its acceptance curve." Reynolds already is test-marketing two new cigarette products based on the research that led to the creation of Premier -- a low-smoke cigarette known as Vantage Excel, and Chelsea, a cigarette with what company officials call a "fresh aroma." Reynolds had billed Premier as a "cleaner smoke," because it virtually eliminated cigarette ash and smoke as well as the burning of certain harmful compounds found in tobacco. Unlike regular cigarettes, the tobacco in Premier was warmed by air drawn through the cigarette from a lit piece of carbon on the cigarette's tip. By eliminating the burning of tobacco, Reynolds officials argued that Premier virtually eliminated the smoke and "controversial compounds" produced by conventional cigarettes. Reynolds spokeswoman Betsy Annese said the marketing tests showed that consumers were interested in the concept of a smokeless cigarette, but the product ran into problems in the area of "taste, aroma and consumer education." "Premier does require some adjustments," she said. Among other things, consumers reportedly had difficulty lighting the carbon element in the cigarette. The product also was dogged by criticism from the Coalition on Smoking or Health -- a powerful antismoking group composed of the American Heart Association, the American Lung Association and the American Cancer Society -- that argued that the unorthodox design of the cigarette and its unknown additives should have required it to be reviewed by health officials before being put on the market. Last April, several months before the test marketing of Premier began, the coalition filed a petition with the Food and Drug Administration asking the agency to review the smokeless cigarette as if it were a new drug. The FDA has not yet ruled on the petition. Reynolds conceded that the opposition had hurt Premier's chances for success. "The distortions and the biases and the misinformation created by our critics caused a great deal of confusion," Annese said. "The organizations and groups that attacked Premier used it as a soapbox to air their prohibitionist views on smoking in general." By most industry estimates, Reynolds had spent several hundred million dollars on research and development, invested another $200 million building a small-scale plant to manufacture the product, and spent $125 million manufacturing and marketing Premier last year. However, John Maxwell, a analyst with Wheat, First Securities in Richmond, said, "Hundreds of million of dollars isn't very much when you're talking about tobacco companies."