The head of the NAACP said yesterday that it was "blatant discrimination" for Catholic University to refuse to let some of its students form an NAACP chapter on campus and that the civil rights organization will go to court, if necessary, to get school officials to reverse their stance.

Kweisi Mfume, the NAACP's president and chief executive, said at a news conference across the street from Catholic University's Northeast Washington campus that the decision was an embarrassment to those of the Catholic faith and others who believe that discrimination of any type is wrong.

"This is blatant discrimination in its most naked form," Mfume said. "For years, we have had chapters of the NAACP on the campuses of other Catholic schools such as Georgetown, Trinity College, Fordham and St. John's."

The university decided in April that students could not start an NACCP chapter on campus, saying it would overlap with two existing campus groups and expressing concern about the organization's advocacy of abortion rights.

Mfume said the university's concern about starting another campus organization for black students imposed "a quota system that is not applied to other students of other races."

Victor Nakas, Catholic University's director of public affairs, said the school strongly disagreed with Mfume's characterization of the controversy.

"For us, this issue is not an evaluation of the merits of the NAACP but the principle of our right and responsibility as a university to determine what groups we will or won't permit to be established," Nakas said. "We don't simply accept every request to form a group presented by students simply because they think it's a good idea."

Nakas said Mfume's claim that the university is trying to set a quota on African American organizations "is clearly not the case." Blacks accounted for 386 of the school's 5,740 undergraduate and graduate students last fall.

Mfume complained at the news conference that Catholic University officials had not responded to his repeated telephone calls after an article about the school's rejection of the NAACP chapter appeared Thursday in The Washington Post.

But Nakas said the Rev. David M. O'Connell, the university president, returned Mfume's calls Thursday and left two messages offering to meet with him Monday to discuss the NAACP's concerns. Nakas said O'Connell was out of town attending a family funeral and could not meet any earlier than Monday.

With the spring semester over, only a small group of students attended Mfume's news conference, and most were from NAACP chapters at other colleges. Among those present was William Jawando, who spent much of his senior year at Catholic University trying to get the NAACP chapter approved after a group of 30 students endorsed the idea. Jawando, 21, plans to enter the university's law school in the fall.

Jawando said school administrators told him in April that allowing the NAACP on campus would not be consistent with the mission of the university or the Roman Catholic Church. An NAACP spokesman said it "took a while" for the news to reach top NAACP officials, who spoke out this week.

The National Association for the Advancement of Colored People, founded 95 years ago, is the nation's oldest and largest civil rights organization. It has a half-million members and chapters at about 150 colleges.

In February, the NAACP's board of directors passed a resolution endorsing a woman's right to choose her method of birth control, including abortion. The organization also backed an abortion rights march in the nation's capital in April.