Tobacco companies including Reynolds American Inc. (RAI) and Lorillard Inc. (LO) filed a lawsuit against the U.S. and the Food and Drug Administration, saying that a recent law imposes "unprecedented restrictions" on First Amendment rights.

The FDA received authority in June from lawmakers to regulate the tobacco industry after years of contentious debate in Congress, the public health arena and among tobacco firms. The June legislation allowed for restrictions on advertising and packaging.

Under the new legislation, tobacco companies can't jointly market their cigarettes with non-tobacco products sold at local retailers. Also, they cannot market or describe any products as less harmful than others unless they have approval to do so from the FDA. There had been no specific legislation previously that laid out exactly how tobacco companies could describe the relative risk from different types of tobacco products.

Tobacco companies have worked to develop smokeless products, which some research indicates maybe less harmful than cigarettes. It is still unclear how the FDA will decide to treat these products.

Reynolds says it isn't against the decision to give FDA authority to regulate tobacco, but it is protesting several provisions in the recent legislation. A spokesman said that, among other provisions, the company is opposing those that prevent it from describing certain tobacco products as less harmful even if there is supporting scientific information. Any such claims would first have to be cleared by the FDA and it is still unclear what process the FDA's new tobacco center will use, he said.

Altria (MO), the nation's largest cigarette maker, wasn't part of the lawsuit. Altria, which makes the well-known Marlboro brand, has generally been seen as being hurt less than its smaller competitors by marketing and other restrictions because it already has a large, dominant market share. An Altria spokesman declined comment.

"This suit does not challenge Congress' decision to give the FDA regulatory authority over tobacco products, nor does it challenge the vast majority of the provisions of the new law," said Martin L. Holton III, senior vice president and general counsel for R.J. Reynolds. "However, the law contains provisions that severely restrict the few remaining channels we have to communicate with adult tobacco consumers and, in our opinion, cannot be justified on any basis consistent with the demands of the First Amendment."

Cigarette makers have seen sales shrink in the past decade, and they have already been operating under some restrictions that were part of their 1999 settlement with 46 states.

The new law, though, was backed by Altria Group, parent of industry leader Philip Morris. Critics of the bill said it would protect the company's No. 1 status.

R.J. Reynolds said Monday the plaintiffs are seeking to protect their First Amendment right to communicate with "adult tobacco consumers about their products." The plaintiffs allege the law contains "severe provisions restricting or banning truthful speech, contrary to the requirements of the First Amendment."

The suit was filed in federal court in Kentucky. A representative from the FDA declined to comment.

-By John Kell, Dow Jones Newswires; 212-416-2480; john.kell@dowjones.com; and Anjali Cordeiro; 212-416-2200; anjali.cordeiro@dowjones.com

(Jared Favole contributed to this article.)