In a win for the tobacco industry, a federal appeals court in Manhattan has thrown out a class action on behalf of anyone who ever smoked a “light” cigarette. The lawsuit had sought $800 billion in damages on behalf of 50 million smokers.

A three-judge panel of the 2nd U.S. Circuit Court of Appeals halted the lawsuit yesterday by reversing a district judge’s decision to certify a class of “light” cigarette smokers who could pursue several tobacco companies collectively.

The plaintiffs had claimed that cigarette manufactures deceived them into believing that “light” cigarettes, which have been advertised as providing less nicotine and tar, were less unhealthy than other cigarettes. The plaintiffs allege that smokers who enjoy “light” cigarettes unknowingly end up receiving just as much tar and nicotine because they inhale more frequently or smoke more cigarettes to compensate.

The court found that it was possible that smokers of “lights” had chosen them for reasons other than the alleged health benefits. The decision, written by Judge John Walker, noted that some smokers may have “preferred the taste of Lights, or chose Lights as an expression of personal style.” The existence of smokers who chose “light” cigarettes for those other reasons means that there can be no single class action, the decision said.

The 2nd Circuit’s ruling requires each individual plaintiff to prove that he or she had picked the product because of the perceived health benefits. While that requirement doesn’t end the prospect of individual lawsuits based on “light” cigarettes, it does end the possibility of a class action.

The defendants included the American Tobacco Co., Altria Group, Philip Morris USA Inc., Lorillard Tobacco Co., Liggett Group Inc., R.J. Reynolds Tobacco Co., and others.

The lawyer who argued the case on behalf of the tobacco companies, Theodore Grossman, said the problem with a class action on behalf of all “light” cigarette smokers is that “many people believe ‘light’ cigarettes are just as dangerous as regular cigarettes.”

Mr. Grossman, of the firm Jones Day, said the number of plaintiffs in the proposed class and the amount of money being sought was “astronomical” and “unprecedented in American jurisprudence.”

The lead lawyer for the plaintiffs, Michael Hausfeld, said that individual plaintiffs would push forward with their claims in district court in Brooklyn, before Judge Jack Weinstein. He said there were several class actions on behalf of “light” cigarette smokers in state courts that were pending.

“It’s far from over,” Mr. Hausfeld, of the firm Cohen, Milstein, Hausfeld & Toll, said.