Six weeks after the two sides rested in the Justice Department's racketeering case against the cigarette industry, the presiding federal judge agreed yesterday to let six public interest groups intervene and argue for tougher punishment if the government wins.

The unusual decision by U.S. District Judge Gladys Kessler will allow groups such as the American Cancer Society and the Tobacco-Free Kids Action Fund to make the case that the Justice Department did not properly represent the interests of the public.

In its closing argument on June 7, the Justice Department reduced its requested "remedy," should it prevail, from $130 billion to $10 billion -- a move strongly opposed by the public interest groups.

The groups, which also include the American Heart Association, the American Lung Association, Americans for Nonsmokers' Rights and the National African American Tobacco Prevention Network, will be allowed to argue that the companies should be forced to pay more for smoking-cessation programs. They will not, however, be allowed to enter new evidence.

Kessler wrote that the tobacco companies "vigorously" opposed her decision.

In her order, Kessler referred to her own earlier "concern about changes in the government's position, and lack of clarity and finality about those changes."

She also concluded that "in a case of this magnitude . . . it will serve the public interest for major public health organizations, who have long experience with smoking and health issues, to contribute their perspectives on what appropriate and legally permissible remedies may be imposed should liability be found."

In adjusting its requested remedy from $130 billion to $10 billion and then to $14 billion, the Justice Department said an earlier appeals court ruling had forced it to change its position. Earlier this week, the department decided to appeal that decision to the U.S. Supreme Court.

At issue is whether any smoking-cessation program ordered by Kessler should be offered to a wide range of smokers, or just those who will become addicted to tobacco in the near future.