The dispute among black leaders over black-Jewish relations broke wide open yesterday.

The major catalyst for the public rupture was a Kansas City speech by National Urban League President Vernon E. Jordan Jr., who indirectly but pointedly attacked black leaders who have opened talks with Yasser Arafat, head of the Palestine Liberation Organization.

In a speech before the National Conference of Catholic Charities, Jordan said that the black civil rights movement "has nothing in common with groups whose claim to legitimacy is compromised by cold-blooded murder of innocent civilians and school children."

Even as Jordan was speaking, the Leadership Conference on Civil Rights in Washington issued a statement pleading with all parties in the Black-Jewish flare-up to stop fighting. But that moderate call for peace fell on deaf ears: Jordan's remarks drew immediate and harsh replies from other blacks, including some Baptist ministers, who accused him of "selling out to the Jewish-Israeli lobby."

"This issue is going to separate the men from the boys in terms of who speaks for black people in this country," said one of these, the Rev. George Lawrence, spokesman for the Progressive National Baptist Convention, which represents 1.5 million black American Baptists.

He noted that Jordan had joined other black leaders two months ago in signing a statement supporting former U.N. Ambassador Andrew Young, whose resignation after an unauthorized meeting with a PLO representative touched off the debate over black-Jewish relations.

That joint statement implied at least some support for talking to the PLO. Jordan seems now to be backing off that, Lawrence suggested.

"Any civil rights organization that cannot take a stand without being worried about its white money being cut off doesn't deserve to be a civil rights organization," Lawrence said.

"We understand where Vernon is coming from . . . He doesn't want his bread cut off. We support the right of Israel to exist, too. But we also support Justice for the Palestinian people.

"We're no longer the boys doing what the Jewish community wants us to do in the civil rights movement. It's a sad commentary on black unity that some people don't realize that."

The Rev. Wyatt Tee Walker, pastor of the Canaan Baptist Church in New York City and former chief of staff to the late Rev. Martin Luther King Jr., sent an open letter to New York newspapers yesterday accusing Jordan of betraying the civil rights movement.

"You have brought to an end the masquerade of the Urban League as a civil rights organization," said Walker, who also heads a black Baptist lobbying group called the International Freedom Organization.

Lawrence and Walker's statements ally them with the Rev. Jesse Jackson, national president of Operation PUSH (People United to Save Humanity), the Rev. Joseph E. Lowery, president of the Southern Christian Leadership Conference, and District of Columbia Del. Walter Fauntroy, all of whom personally visited Arafat after Young's resignation.

Jordan's position has support from black mainline moderates. Prominent among them are Benjamin Hooks, executive director of the NAACP, and Bayard Rustin, leader of the labor-oriented A. Philip Randolph Institute. b

Rustin and a group of other black moderates, including Urban League and NAACP representatives, were in Israel yesterday on a peacekeeping mission of their own.

"Speaking for myself, I want to make it clear to the Israelis that there are great numbers of black people who want the United States to give Israel whatever support it needs." Rustin told reporters before departing for Israel Sunday night.

Members of the delegation said their trip had been planned months ago and was not being taken in response to earlier Middle East visits by Jackson, Fauntroy and Lowery.

But that disclaimer failed to impress other blacks, who said Jordan had sided with pro-Israel groups in his speech.

"On the one hand, Vernon is condemning blacks for meeting with the PLO. But here are his own people meeting in Israel with Israelis today, and he isn't saying a damned thing about that," said a spokesman for a black member of Congress, who requested anonymity.

Though Jordan mentioned no names in his speech, his close aides and associates said his words were aimed at Jackson, Fauntroy and Lowery.

The situation proved distressing to officials of the Leadership Conference on Civil Rights, which represents many of the black and Jewish factions in the dispute.

Conference Chairman Clarence M. Mitchell and secretary Arnold Aronson yesterday tried to quell the argument, saying that fighting was getting in the way of the larger aims of the civil rights movement.

"The work that still must be done is too important to let differences divide us," the officials said in a joint statement.

"A free plural society demands not the elimination of differences but the expression of differing views without rancor, racism or anti-Semitism," the statement said.

Mitchell and Aronson said that the conference's commitment to full employment, equality in education and housing, and quality health care "continues undiminished."