Charlotte, N.C. ? The Illinois Supreme Court handed the tobacco industry a huge victory Thursday by tossing out a $10.1 billion fraud judgment against Philip Morris USA over the marketing of its “light” cigarettes.

But while shares of parent company Altria Group Inc. soared to an all-time high on the news, industry critics warned that the Illinois decision does not insulate U.S. cigarette firms from future lawsuits. There are at least 40 similar suits pending against companies like Philip Morris and Reynolds American, any of which could result in awards into the billions of dollars, tobacco opponents said.

“They need to keep their legal teams ready,” said Richard Daynard, president of the Boston-based Tobacco Control Resource Center and a longtime industry foe.

Philip Morris USA, which makes the popular Marlboro brand and controls about half the U.S. cigarette market, issued only a terse statement, saying the Richmond, Va.-based company was “gratified” by Illinois court’s decision.

The Illinois high court’s ruling in Price vs. Philip Morris – the so-called “price lights” case – addressed whether Philip Morris acted fraudulently when it labeled some cigarettes as “light” or “low tar and nicotine.”

By a 4-2 vote, the court found that the U.S. Federal Trade Commission had authorized such characterizations.

“If the FTC has specifically authorized the use of the terms …. (Philip Morris) may not be held liable under the Consumer Fraud Act, even if the terms might be deemed false, deceptive or misleading,” Justice Rita Garman wrote for the majority.

“I think they (Philip Morris) can take some comfort from this victory,” said Carl Tobias, a law professor at the University of Richmond who follows tobacco litigation. “It does seem like this could dissuade individuals from pursuing them vigorously in other states.”

However, Mark Gottlieb, executive director of the Tobacco Products Liability Project at Northeastern University, said the lights fight was far from over.

Gottlieb estimated damages from similar suits pending in courts around the country could go as high as “tens of billions of dollars.”