A federal judge ruled in favor of tobacco industry lawyers yesterday in a dispute over whether they had lobbied New Jersey state legislators for a 1987 product-liability law that weakened a pending lawsuit.

Modifying a December order, U.S. District Judge H. Lee Sarokin in Newark barred the plaintiff's lawyers from taking depositions from the defense counsel on whether they had drafted or influenced a legislative committee's report interpreting the law.

Sarokin had held last October that the report compelled him to strike the lawsuit's "risk/utility" claim retroactively. The claim was that cigarettes are an "unreasonably unsafe" and consequently "defective" product because their risks exceed their usefulness.

In courtroom argument Thursday, Donald J. Cohn, a lawyer for Liggett Group Inc., said the constitutional separation of powers among the branches of government denies a court the power to investigate the acts of a legislature or of a legislative committee.

The plaintiff's lawyer, Cynthia A. Walters, argued that there was no precedent barring Sarokin from letting the depositions to be taken so that he could assess the weight to give the report in court.

Sarokin held that the legislative committee's report had to control the case, and that its origins weren't relevant. If there were impropriety in its preparation, it would be up to the legislature to look into it, he said.

Walters and Marc Z. Edell, her associate, represent Antonio Cipollone, whose wife died of lung cancer, in the case, which is set to go to trial on Jan. 29.

The Cipollone lawyers fared better in a dispute with the defendants -- P. Lorillard Inc., Philip Morris Inc. and Liggett -- over their subpoenas of eight defense lawyers as potential trial witnesses. The plaintiffs said the lawyers had "knowledge of and/or participation in events ... pertinent to the lawsuit," such as studies of health risks.

The defendants -- joined by other companies and industry organizations -- denounced the subpoenas as "outrageous" and asked Sarokin to quash them. Yesterday, in a mixed ruling, he preserved Edell's and Walters's right to subpoena six of the lawyers, but dismissed the subpoenas for Patrick M. Sirridge of Shook, Hardy & Bacon of Kansas City, Mo., counsel for Philip Morris, and for Cohn.

Acting on a plaintiff's motion, Sarokin gave another tentative victory to Edell by asking him to prepare an order that -- subject to the companies' objections -- would require them to list the nontobacco ingredients of their cigarettes, such as additives and pesticides.

The trial is expected to last four months or longer.