Shares of cigarette makers

Altria

(MO) - Get Report

and

R.J. Reynolds Tobacco

( RJR) finished lower after a report said two Missouri lawsuits involving so-called light cigarettes had received class-action certification.

Judge Michael David certified the lawsuits, which allege that the tobacco companies misled smokers about the health risks of "light" cigarettes, according to

Bloomberg

.

The news follows a decision by a Florida court last week to toss out a class-action suit over "lights," in addition to other legal victories for the industry last year.

"This certification clearly runs counter to recent court actions maintaining that the difference in the plaintiffs predominate over the similarities in these cases and thus they are not appropriate for class action," said Ellen Matthews, a spokewoman for RJR, in comments on

Bloomberg

.

Altria fell 41 cents, or 0.8%, to $53.83, while RJR lost 91 cents, or 1.6%, to $57.79.