In a speech to the United Nations Women's Conference, chief U.S. delegate Maureen Reagan said today that the United States has no intention of denying Palestinian women or South African women opposed to apartheid the use of the conference as a platform to voice their grievances.

The speech was viewed by some delegations as surprisingly conciliatory and evoked qualified praise from women representing the Palestine Liberation Organization, the anti-apartheid African National Congress and the government of Nicaragua. However, it was denounced by American feminists. They called Maureen Reagan's boasts about the advancement of American women "total double talk" and charged that women's rights have been eroded under the Reagan administration.

The U.S. delegation had come into this conference vowing to keep "political issues" from dominating "the unique concerns of women," which it had maintained were the only "legitimate" business of the conference.

While the president's daughter did not explicitly back away from that position today, she said that "the question of apartheid in South Africa . . . is of utmost importance" to the Women's Conference. She also referred specifically to the problems of "Palestinian women."

At the last U.N. Women's Conference, in Copenhagan in 1980, the United States complained angrily about how supporters of a proposed Palestinian homeland dominated the conference and forced passage of a final document equating Zionism with racism.

Maureen Reagan's speech today, however, appeared to placate representatives of the PLO, who have official observer status at the conference. "At least the U.S. administration has called us by our name," said Abu Khadra, secretary general of the Union of Palestinian Women. "It is a step forward in our relationship."

The woman heading a delegation from the African National Congress, a resistance group that has been banned by the South African government, said she was both pleased and surprised to hear the head of the U.S. delegation condemn apartheid as "demeaning and destructive" to South African blacks, especially women. Gertrude Shope, head of the women's section of the ANC, said that while Maureen Reagan could have gone further in condemning apartheid, "what she said was very interesting."

While groups that are traditional enemies of the United States at international forums such as this gave lukewarm praise to the speech, several American feminists here, who are not official delegates to the conference, convened a press conference at which they characterized Maureen Reagan's remarks as "rosy rhetoric" that "ignored facts."

Representatives of the National Organization of Women seized, in particular, on a reference in the speech to the "space flight of the first American woman astronaut," Sally Ride, as an example in America "of the dramatic progress during this decade for women."

"It is true that the acheivement of having a woman in space was an inspiration to every women in the United States," said Stephanie Clohesy, executive director of NOW's legal defense and education fund.

"But Sally Ride herself acknowledges that she would not be in the space program if it had not been for the affirmative recruitment required under Title 9," Clohesy said, referring to a 1972 amendment to the Civil Rights Act.

That provision of the Civil Rights Act was overruled, in effect, by a 1984 court decision, and the Reagan administration has resisted attempts to reintroduce in Congress a bill that would restore the law.

Ride and her mother are featured in a public service advertisement, now running in American magazines, in which they credit the Title 9 law not only for opening up opportunities for Ride but for women all over the United States.

"To take credit for a Sally Ride without acknowledging that we may never have another is unfair and does not serve the purpose of why U.S. women are here," Clohesey said.

Today's speech was interrupted twice by applause, which was the most enthusiastic when Reagan proclaimed that she would "never deny to any woman an opportunity such as that presented here to use this platform, no matter how much I disagree with her position."