A federal judge struck down the Army's equal-opportunity promotion process yesterday, saying the policy gives undue preference to women and minorities at the expense of white, male officers.

The Army's written direction to promotion boards that urges them to consider the "past personal or institutional discrimination" faced by women and minorities is unconstitutional because the policy does not order the board also to consider possible discrimination against white men, the judge found.

"This undeniably establishes a preference in favor of one race or gender over another, and therefore is unconstitutional," U.S. District Court Judge Royce C. Lamberth wrote in a 68-page opinion.

The decision came in the three-year-old case of retired Lt. Col. Raymond Saunders, a white officer who was twice denied promotion to the rank of full colonel in 1996 and 1997. He retired in 1999 as a judge advocate general -- an Army lawyer -- and then filed suit.

His case is one of several filed by white Army officers, and a fewer number filed by officers in other branches of the armed services, that allege the military has been giving too much consideration to race and gender in promotions.

Lamberth's ruling, which legal analysts said yesterday closely followed Supreme Court precedent, finds that Army policies emphasizing race and gender considerations were not justified because the agency failed to show any history of discrimination against women or minority officer candidates.

If the ruling stands, it would require the Army to remove such considerations from its promotion process. It also would allow Saunders's lawsuit to proceed, and to deny his claim the Army would have to prove that he would not have been promoted anyway.

Relying on Army data, mostly dating from 1970 onward, that showed black officers being promoted at virtually the same rate as whites -- if not slightly higher -- Lamberth's opinion reasoned that there was no factual basis for the Army to take race or gender into account in its promotion process.

"This case will have enormous impact," said Eugene R. Fidell, a Washington attorney who specializes in military law. "It's likely to sound the death knell for military promotion decision-making where there's an actual or imaginary thumb on the scale."

The ruling could affect thousands of promotions in the Army in the past six years, analysts and lawyers involved in reverse-discrimination lawsuits said yesterday, as well as alter the playing field in days to come. The decision would not affect any officers already promoted.

"The court has declared the Army's officer promotion standards to be unconstitutional. A lot of other people are obviously going to be using this as a precedent," said Christopher A. Sterbenz, the attorney representing Saunders and nine other white officers in similar suits. The Army had not reached a decision yesterday on whether to appeal the decision, said Maj. Steven Stover, an Army spokesman. It was not immediately clear whether the Bush administration, which has been cool to some affirmative action programs but has let others stand, would become involved in the case.

The Army rule in question instructs members on promotion panels that the "[s]uccess of today's Army comes from total commitment to the ideals of freedom, fairness and human dignity," and says that they must be alert to past discrimination and take it into account. It also says that the number of promotions given should match the percentages of women and minorities in the pool of applicants if at all possible.

The ruling is not expected to have any implications for civilian affirmative action programs because it is narrowly tailored to the modern Army's recent history, civil rights attorneys said yesterday.

"It's a decision in the tradition of the Supreme Court and of the D.C. Circuit," said John Relman, a prominent civil rights attorney in Washington. "I think it's unlikely the decision would be overturned."

The Army's role in American attitudes on race has been historically profound, and gave yesterday's ruling an added dimension of irony. Black soldiers who served abroad in the first half of the 20th century found it intolerable to return to racism and segregation, and their resolve to be treated equally at home helped form the backbone of the civil rights movement. When the Army became one of the first federal agencies to officially desegregate, it set an example that would slowly be followed by the rest of society.

In the Saunders case, Army hiring reports from the 1970s, 1980s and 1990s showed that racial discrimination in officer promotion had largely disappeared over time, according to the court's finding yesterday. That is significant because the Supreme Court has held that for an affirmative action program to be legal, it must be established in an institution that has a clear, demonstrable record of racial or gender discrimination.

Staff writers Thomas Ricks and Steve Vogel contributed to this report.