ASHINGTON, Nov. 17 — A dispute within the Supreme Court over what, if anything, to do next about affirmative action broke into the open on Monday when two justices dissented from the court's refusal to take up a white-owned construction company's challenge to an affirmative action program for public contracting in Denver.

The court had been considering the appeal since the end of the summer recess, an unusually long time, and turned it down on Monday without comment from the majority. That prompted Justice Antonin Scalia to file a 10-page dissent that Chief Justice William H. Rehnquist signed.

The two justices objected that in upholding the affirmative action plan, the federal appeals court in Denver had failed to insist on sufficient proof that the program was necessary to overcome existing discrimination in the construction industry. By failing to take the appeal, the two justices said, the Supreme Court in effect blessed what they characterized as a slippage from the rigorous review required by court precedents.

Denial of the appeal "is important because of what it signals about this court's ongoing commitment to exacting judicial review of race-conscious policies," the dissenters said. Referring to one of the most important precedents in this area, a 1989 decision that invalidated a minority set-aside program for public contracts in Richmond, Va., they said the latest action "invites speculation that that case has effectively been overruled."

Justices have often cautioned that no more can be read into a denial of review than that an appeal failed to attract the necessary four votes. But in this instance, that fact alone added more than passing interest to an otherwise routine event. (The court denied 176 other cases on Monday along with this one, Concrete Works of Colorado v. City and County of Denver, No. 02-1673.)

The silence of the court's two other strong opponents of affirmative action, Justices Clarence Thomas and Anthony M. Kennedy, was notable, given that they could have provided the necessary third and fourth votes to grant review.

Those two justices, along with Justice Scalia and Chief Justice Rehnquist, dissented from the decision in June that upheld the University of Michigan's affirmative action plan for admission to its law school. In her majority opinion in that case, Justice Sandra Day O'Connor suggested that the court would not choose to revisit the issue, at least in the context of higher education, for the next 25 years. Part of the internal struggle on the court now may be over just how tightly it meant to draw a curtain over the general subject of minority preferences.

On the other hand, the denial may reflect the conclusion of the missing justices, and perhaps others, that this case was a poor vehicle for a renewed exploration of the permissible boundaries of race-conscious government policies.

"I think it signifies that if any program could withstand strict scrutiny, it was this one," Eileen Penner, a Washington lawyer who filed the brief for Denver in support of the program, said in an interview. "It's possible they thought the evidence of discrimination was so clear under any standard that there was no reason to take the case."

Under court precedents, the existence of discrimination in a general sense is not sufficient to justify an affirmative action program. Rather, there must be evidence of discrimination in the market or industry that the program is addressing.

In this case, the Federal District Court in Denver found the evidence insufficient, but the United States Court of Appeals for the 10th Circuit took a fresh look at the evidence and upheld the program. Though the appeals court's analysis tracked closely with other cases, Justice Scalia found it inadequate.

The Denver program, incorporated in three city ordinances, does not impose a quota or set-aside. Rather, it requires prime contractors to show that they have solicited bids from minority-owned subcontractors and that they have not rejected a lowest bid from a qualified minority-owned company. A white-owned company, Concrete Works of Colorado Inc., filed suit in 1992 after losing three contracts.

After announcing its orders on Monday morning, the court began a Thanksgiving recess that will last until Dec. 1. Those awaiting a decision in the campaign finance case that was argued in a special session in September will have to wait until at least Dec. 2, the next day on which the court is scheduled to announce decisions.

In other action on Monday, the court turned down an appeal from an inmate on death row in Oklahoma. The inmate is a Mexican citizen who at the time of his arrest in a double killing in 1995 was not given the rights guaranteed by an international treaty, the Vienna Convention on Consular Relations. The treaty requires that immediately after arrest, a foreign citizen be told that his country's consul can be informed of the situation.

The prisoner, Osbaldo Torres, who was 18 at the time of his arrest, did not receive this information and has tried unsuccessfully to challenge his conviction and sentence through a petition for a writ of habeas corpus. The Mexican government has taken a great interest in the case, Torres v. Mullin, No. 03-5781, and filed a brief asking the justices to defer action until the International Court of Justice can decide a complaint that Mexico brought in January on behalf of Mr. Torres and 53 other Mexicans who have been sentenced to death in the United States.

Justices John Paul Stevens and Stephen G. Breyer objected to the denial of review. "Given the international implications of the issues raised, I believe further information, analysis and consideration are necessary," Justice Breyer wrote. Justice Stevens objected that the court was allowing "state courts to disregard the nation's treaty obligations."

The action on Monday was not necessarily the court's last word on the issue. Similar petitions have recently been filed on behalf of two Colombian citizens who are on death row in Kansas. The court was scheduled to act on those cases, Ortiz v. United States, No. 02-11188, and Sinisterra v. United States, No. 03-5286, earlier this month, but instead requested the record of the lower court proceedings for further review.