The Supreme Court ruled Monday that a federal law regulating tobacco product labeling does not bar a group of Maine smokers from using a state consumer protection law sue a major tobacco company.

The justices ruled 5-4 in the case of Altria Group Inc. v. Good that a 1965 law, the Labeling Act, does not pre-empt a lawsuit the Maine group filed in federal court against Altria, owner of Philip Morris USA, Inc. The Maine smokers based their claim on a state unfair trade practices law.

The lawsuit claims the company’s advertising fraudulently represented that smokers of “light” cigarettes ingested less tar and nicotine than smokers of regular cigarettes, when the company knew that was not the case.

The 1965 law established federal health warning labeling requirements for cigarettes. It also mandated that no “requirement or prohibition based on smoking and health shall be imposed under state law” regarding advertising or promotion of cigarettes packaged with the requisite labeling.

That provision, the court ruled, did not pre-empt a fraud claim by the Maine smokers because such a claim is not based on smoking and health.

“We conclude . . . that the Labeling Act does not pre-empt state-law claims like respondents’ that are predicated on the duty not to deceive,” Justice John Paul Stevens wrote in the court’s opinion.

Altria had won a summary judgment in district court, but the U.S. Court of Appeals for the First Circuit reversed. The Supreme Court’s decision sends the case back down to the district court.

It was the industry’s second setback in a month. On Nov. 26, the Federal Trade Commission revoked 42-year-old guidelines that had allowed cigarette manufacturers to tout some of their products as low in tar or nicotine. The commission rescinded government approval for a testing method that uses a “smoking robot” to measure tar and nicotine content in order to label some cigarettes as “light” and “low-tar.”