Tobacco company stock prices actually rose after the committee released its report, which concluded "removal of menthol cigarettes from the marketplace would benefit public health in the United States."

The advisory panel laid out a detailed critique of the special dangers posed by menthols, including evidence that they are a significant factor in the rise of smoking among adolescents and that the flavoring facilitates addiction.

But the panel's determinations are not binding on the Food and Drug Administration, which will decide what, if any, action to take. And the tobacco companies are expected to marshal potent political and legal resources to delay any new restrictions for years to come.

There is potentially strong congressional opposition to a sweeping new regulatory push by the government, especially in the GOP-controlled House, where a majority of Republicans voted against the 2009 legislation granting the FDA authority to regulate tobacco, said Michael Siegel, a Boston University expert on the public health consequences of smoking.

And President Barack Obama may be reluctant to take on another controversial issue at a time when he is fighting to defend his signature health care overhaul and engaged in difficult negotiations over the federal deficit and other issues.

"The last thing he needs, politically, is government telling tobacco companies what to put into cigarettes," Siegel said.

There is also concern over losing tax revenue if cigarette sales decline, as well as over the possibility that a black market would develop.

In crafting the 2009 tobacco law, Congress called for a ban on candy, fruit, spice and other flavorings in cigarettes because of their potential allure to young smokers. Menthol flavoring was not banned because declaring nearly one-third of the cigarette market illegal was thought to be too disruptive and politically unpalatable.

By Andrew Zajac McClatchy-Tribune Newspapers