June 25, 1982 LEADERS CONCEDE LOSS ON EQUAL RIGHTS

By MARJORIE HUNTER, Special to the New York Times

WASHINGTON, June 24— Leaders of the fight for an equal rights amendment officially conceded defeat today. But they vowed to continue the struggle for equality of women by electing their backers to state legislatures and by suing corporations that practice sexual discrimination.

''We've just begun to fight,'' said Eleanor Smeal, the president of the National Organization for Women, the group that spearheaded the Equal Rights Amendment Countdown Campaign, which has now ended in defeat.

In the 10 years since Congress passed the proposed constitutional amendment to forbid discrimination on the basis of sex, it has been ratified by 35 states, three short of the three-fourths it needed to become part of the Constitution.

Hopes for ratification before the deadline next Wednesday were dashed this week when the amendment was rejected by the Illinois House and the Florida Senate, two states in which supporters felt they had a fighting chance. Hope for One of Two Others

Had Illinois and Florida ratified the amendment, there was at least some chance that either Oklahoma or North Carolina would have provided the final needed vote.

Prospects were far slimmer in the other nonratifying states: Alabama, Arizona, Arkansas, Georgia, Louisiana, Mississippi, Missouri, Nevada, South Carolina, Utah and Virginia.

Phyllis Schlafly, a leader of a group called Stop-ERA, hailed the defeat of the amendment tonight, saying: ''They realized E.R.A. is dead and I think that that is an admission they have lost the battle. My feeling is that E.R.A. will take its place with the prohibition and the child labor amendments as ones which did not have enough support of the American people to be in the Constitution.''

A bipartisan group of at least 38 senators, led by Bob Packwood of Oregon, a Republican, and Paul E. Tsongas of Massachusetts, a Democrat, will introduce new legislation in Congress on July 14, calling again for a constitutional amendment that would have to be ratified by three-fourths of the state legislatures.

But at her crowded news conference today in the organization's storefront headquarters on Pennsylvania Avenue, between the Capitol and the White House, Mrs. Smeal said her organization would ''not again seriously pursue the E.R.A. until we've made a major dent'' in the memberships of Congress and state legislatures by electing more women and ''men who are genuinely feminists.''

She said that NOW, with a membership of 200,000 and a goal of at least a million members, intended to create ''an independent political force'' to unseat legislators who opposed equal rights and recruit and elect those pledged to support the amendment. Says G.O.P. 'Led the Attack'

While she said the new movement would work in both major political parties, she was critical of the Republican Party, saying that it ''actually led the attack'' against the amendment. Although she was less critical of the Democrats, she said that ''women's rights were not high on their agenda and there was significant defection in their ranks.''

To carry on the fight ahead, Mrs. Smeal said, the organizations have a large war chest. She said that donations had averaged $1 million a month in recent months and were still pouring in.

''We're now raising more money than the Democratic Party,'' she said. ''If our opponents think it's all over, someone should tell them we've just begun to fight.''

While critical of state legislators who voted against the proposed amendment, Mrs. Smeal said: ''The real opposition, behind the visible political opposition, has been the special corporate interests that profit from sex discrimination.'' She Accuses Corporations

Major corporate interests, she said, made heavy contributions to the opposition to the equal rights amendment. In the months and years to come, she said, she expects to see big corporations and other special interests ''fighting us as we work to ban discrimination in insurance or to win better wages for women.'' She said that the National Organization for Women would spearhead efforts to boycott, and in some cases to sue, businesses that practiced sex discrimination. She did not cite any specific corporations.

While the battle over the equal rights amendment has been waged more intensely in the last few years, the effort to achieve such an amendment dates from 1923, when legislation was first introduced in Congress. It Passed in 1972

In 1972, the proposed amendment passed the House by the wide margin of 354 to 24, and the Senate by an equally top-heavy vote, 84 to 8. It was a one-sentence amendment: ''Equality of rights under the law shall not be abridged or denied by the United States or any state on account of sex.''

In two hours after it cleared Congress, the amendment had been ratified by Hawaii. And in the months that followed, it handily won approval in a number of other state legislatures.

But by the spring of 1973, opponents had mounted a strong campaign, arguing that it would result in forced military service for women; a dilution of existing laws protecting women in the workplace; homosexual marriages, and unisex public toilets. Furthermore, they argued that existing laws provided equality for women. Proponents of the measure rebutted or minimized allegations of such consequences.

The bill had stipulated that the states had five years in which to ratify. As the deadline in the spring 1979 approached, the amendment was still three states short. Over the objections of forces opposed to it, Congress in the fall of 1978 granted a 36-month extension, which ends next Wednesday.