Civil rights advocates, union leaders, administration officials and women's rights groups heralded yesterday's Supreme Court ruling in the Brian Weber case as their long-awaited mandate to push for sweeping affirmative-action programs across the country.

At the same time, yesterday's ruling was decried as a high court sanction of strict numerical quotas by those who had supported Weber in his claim that he was a victim of reverse discrimination.

One Immediate Consequence of the ruling was the announcement by the head of the Equal Employment Opportunity Commission that the EEOC may amend its guidelines to allow more vigorous crackdown on job discirmination.

EEOC head Eleanor Holmes Norton said in an interview after the decision that she was "looking at whether or not we should amend the guidelines" adopted in December. Those guidelines require affirmative action programs only where there is a "reasonable" basis to believe discrimination existed in the past.

But in its 5-to-2 decision, the court ruled that there does not have to be a past history of discrimination, only evidence of a current racial imbalance, and that makes the court mandate broader than the EEOC's requirement.

"We're going to look at the guidelines" for possible revision, Norton said, adding that the current guidelines were adopted after the more restrictive Allan Bakke decision last year.

But where the decision in the celebrated Bakke case left proponents of affimative action confused and the reverse discrimination issue largely unresolved, civil rights leaders yesterday wasted no time in claiming a major victory in the Weber case.

Some even suggested that the ruling was the most important advancement for minorities since the Brown vs. Board of Education decision 25 years ago.

"Today's decision in the Weber case inspires hope that the nation will embark on a new thrust to secure equality for minority citizens," said Vernon Jordan of the National Urban League at a New York news conference.

Jordan said the ruling "suggests a positive obligation for private employers to press forward with broad, comprehensive affirmative-action programs. They had a legal mandate to do so before Weber. Now they have no excuse."

In Louisville, where the NAACP is holding its 70th annual convention, news of the decision spread quickly and was greeted with the expected exhilaration.

"We applaud this decision," said NAACP executive director Benjamin Hooks. He called the Weber ruling "the most important civvl rights decision in recent history."

Hooks said the Bakke decision last year was a defeat for blacks largeey because the media and others initially interpreted the ruling adversely for minorities. This time, he said, the NAACP will begin a massive public relations campaign to make sure the Weber decision is "correctly interpreted" as a victory.

Women's rights activists also claimed victory yesterday, since the affirmative action programs at issue involve women who also may be under-represented in the workforce. Eleanor Smeal, president of the National Organization for Women (NOW), said in a telephone interview after ruling, "Now it's decided - affirmative-action programs are positively legal under title VII."

Opponents of the affirmative-action program in the Weber case had argued that while the intent was good, strict numerical quotas were arbitrary and discriminatory. They were able to take some solace in the narrow language of the court's 13-page decision, which they interpreted as having limited implications.

"It was a strict, narrow decision," said Larry Lavinsky, chairman of the National Civil Rights Committee of B'nai B'rth's Anti-Defamation League. "Private employers may read this decision as sanctioning racial quotas, but if they do, they're going to be in a lot of trouble."

Lavinsky said, "It seems to me what they tried to do was come up with a very narrow decision supporting this particular program under these particular circumstances . . . It's a very limited sanction of that kind of a strict numerical approach under grievous circumstances. Those who support quotas down the line did not get that kind of broad sanction."

That response was similar to that by another Jewis organization, the National Jewish Commission, which, like B'nai B'rith, has traditionally opposed racial quotas because Jews have been victims of them in the past.

"It's a disturbing decision actually," said Dennis Rapp, a National Jewish Commission attorney who filed a friend-of-the-court brief supporting Weber. "I'm really afraid it will lead to enormous pressure on corporations to institute those types of programs."

Rapp said the decision in effect allows discrimination against one race - in Weber's case, whites - when a company is trying to make its workforce reflect the racial makeup of the community. "That's incredible. That's absolutely incredible. They've never said that before. This is an incredible break from the past."

Rapp said, "The ones who are going to suffer are primarily going to be Jews. It's a very shocking decision."

The long-range implications of the decision for corporations considering their own affirmative-action programs is unclear. While some civil rights advocates and union leaders predicted an immediate push to establish broad affirmative-action programs, others predicted that the pace will be much slower and more measured than this initial euphoria suggests.

E. Richard Larsen, national staff counsel for the American Civil Liberties Union, said, "The continuing struggle now is to convince all employers to adopt and vigorously implement meaningful affirmative-action plans."