CHICAGO (MarketWatch) -- In a legal blow to the tobacco industry, the U.S. Supreme Court held Monday that federal labeling laws do not protect marketers of what are called "light" cigarettes from being sued under state antifraud statutes for false advertising.

The 5-4 ruling in Altria Group v. Good means that a group of Maine consumers can go ahead with a state lawsuit against Altria that charges the company with deceptive advertising of its light brands. At issue were federal rules about cigarette labeling and advertising, which Altria claimed preempted state laws. A federal district court initially agreed with Altria only to be later overturned on appeal. The high court made no ruling on the merits of the case, merely allowing it to proceed.

Writing for the majority, Justice John Paul Stevens said that the federal "Labeling Act does not preempt state-law claims like respondents' that are predicated on the duty not to deceive," and also held that the Federal Trade Commission's "various decisions with respect to statements of tar and nicotine content do not impliedly preempt respondents' claim."

Still, he added, "respondents still must prove that petitioners' use of 'light' and 'lowered tar' descriptors in fact violated the state deceptive-practices statute, but neither the Labeling Act's preemption provision nor the FTC's actions in this field prevent a jury from considering that claim."

Stevens was joined by Justices Anthony Kennedy, David Souter, Ruth Bader Ginsberg and Stephen Breyer.

Justice Clarence Thomas, joined in dissent by Chief Justice John Roberts, Antonin Scalia Samuel Alito, wrote that the majority misread precedent and that the ruling could well "have the perverse effect of increasing the nonuniformity of state regulation of cigarette advertising," a problem that Congress intended to remedy with the Labeling Act.

"While we had hoped for a dismissal based upon federal preemption, it is important to note that the Supreme Court made no finding of liability," wrote Murray Garnick, Altria's associate general counsel, in a response. "We continue to view these cases as manageable, and the company will assert many of the strong defenses used successfully in the past to defend against this very type of case."

Ed Sweda, senior attorney for the Tobacco Products Liability Project at Northeastern University School of Law, said that the opinion "gives the green light to the victims of the tobacco industry's 'light' cigarette scam to have their case heard before a jury of their peers."

It is a "victory for consumers who were deliberately deceived by an industry that came within one vote today of getting an absolute shield of immunity for decades of wrongdoing."