Among the most significant statements by the executives were those that confirmed that tobacco companies could control the amount of nicotine in cigarettes by varying the types of tobacco and the parts of the tobacco plant that were used in a particular blend. They said a number of their cigarettes, primarily low-tar brands, did use high-nicotine blends, which gave more nicotine to the smoker than the cigarettes might have otherwise given. They use these blends for flavor, they explained.

On the Reynolds company's widely criticized use of the cartoon figure Joe Camel to promote its Camel brand, Mr. Johnston of Reynolds apologized for an ad that recommended that young men seeking dates at the beach drag women from the water, pretending to save them from drowning.

"That ad ran once," he said. "It never should have run. I apologize. It was offensive. It was stupid. We do make mistakes." Concerned About Fires

While most of the exchanges focused on the health risks of cigarettes, the executives were also asked about other risks posed by their products, like fire. The president and chief executive of Philip Morris, William I. Campbell, was asked about the feasibility of making cigarettes whose paper tubes would pose less danger of starting fires. Cigarette companies have said this type of cigarette would be difficult to draw smoke through and would taste bad. Representative Albert R. Wyden, Democrat of Oregon, noted that the Virginia Slims brand was considered less of a fire hazard than others, and he asked Mr. Campbell, whose company makes the brand, if a Virginia Slim was difficult to smoke.

"As a matter of fact, it is too hard to smoke, and doesn't taste very good," snapped Mr. Campbell. He said the company had been unable to make a commercially acceptable and fire-safe cigarette.

Pressed by the subcommittee's chairman, Henry A. Waxman, Democrat of California, and by Representatives Wyden and Mike Synar, Democrat of Oklahoma, the companies agreed to supply many private company papers, including all the research on humans and animals concerning nicotine and addiction, all the market research and internal memoranda on Reynolds' Joe Camel advertising campaign and all the research done by the Philip Morris researcher whose scientific paper on addiction was blocked from publication by company executives.

At one point during the hearing, Mr. Wyden presented a stack of data from medical groups and a 1989 Surgeon General's report on the perils of smoking, asking each executive in turn if he believed that cigarettes were addictive. Each answered no.