The 10 black bishops of the Roman Catholic Church in this country have challenged their brother bishops to stamp out racial prejudice, saying it continues to make black Catholics "feel unwelcome" in their church.

Just as some whites feel that "black neighbors, black co-workers and black classmates will be disruptive of their value system and their familiar patterns of life, some white Catholics feel that it will be equally disruptive to share the Scriptures, the bread of life and the cup of salvation [holy communion] with black Catholics," said Bishop Joseph L. Howze of Biloxi, Miss.

White Catholics may "feel sorry" for blacks or "even feel guilty about their plight," Howze said, but whites do not welcome blacks to their churches. Consequently, "many black Americans still feel unwelcome in the Catholic Church."

Howze, the senior of the 10 black bishops and the only one to head a diocese, presented their joint statement Tuesday at a closed-door session of the National Conference of Catholic Bishops, which agreed to make the statement public yesterday. About 1.2 million of the nation's more than 52 million Catholics are black, Howze said.

Howze disputed the "prevailing myth" that the remainder of American blacks are members of Protestant churches. Many, he said, "are simply unchurched."

In order to reach them, the black bishops asked help in developing "black Catholic styles of public worship," evangelistic efforts in black communities, racially sensitive recruiting of black men and women into religious work, and more blacks in leadership roles involving white as well as black Catholics.

They cited the example of Episcopal Bishop John T. Walker of Washington, who is black. He "was not chosen because of the number of black Episcopalians in Washington," they said, but "because he has qualities that are needed to head the Episcopal Church in this area."

Only hours earlier, the national bishops' conference had elected Auxiliary Bishop Eugene Marino of Washington as secretary -- the first black bishop elected to a major leadership post.

In other actions the bishops moved toward possibly toughening their controversial 1983 pastoral letter on nuclear warfare, which said that the nation's policy of nuclear deterrence is "morally acceptable" only if the nuclear powers pursue disarmament and weapons-reduction agreements.

Six activist bishops, led by Auxiliary Bishop Thomas Gumbleton of Detroit, said, "In the judgment of many people, these strict conditions for the moral acceptance of deterrence are not being met."

In executive session, the bishops agreed to name a committee to study the deterrence situation and recommend, at next year's meeting, whether to change their stance.