A top official of the Seventh-day Adventist Church, acceding to a demand first made by black church leaders six years ago, publicly apologized yesterday for a remark he made in a 1979 internal memorandum that the leaders said was offensive to black members. Nearly a fourth of the church's North American members are black.

Ken Mittleider, who is white and one of five vice presidents of the church, told about 200 church leaders from around the world gathered for an annual conference at the Seventh-day Adventist Church in Takoma Park that his remarks arguing against hiring a white woman he described as "a crusader" for black causes was not meant as a racial slur.

"I ask forgiveness of anyone who came to that conclusion. From the depths of my heart I ask that you please forgive me," a church spokesman quoted Mittleider as saying during an unscheduled, 15-minute speech detailing his motives in writing the memo Oct. 30, 1979.

In it, Mittleider urged that Carol Rayburn, a former officer of the Black Forum, a student group at Andrews Seminary in Michigan, be denied an internship at the Potomac Conference and a pastoral associate post at Sligo Church in Takoma Park. Rayburn filed a complaint with the Equal Employment Opportunity Commission alleging that the church refused to hire her because of her ties with blacks and black-oriented church groups. The case later went to court.

A federal appeals court, citing the constitutional separation of church and state, ruled last month that antidiscrimination laws did not apply in Rayburn's case.

In the 1979 memo, Mittleider wrote of Rayburn, "She is a crusader. You will notice one of the activities she joined in at Andrews is the Black Forum. She will constantly be working for the 'underprivileged,' trying to better their situation from a material standpoint."

Warren Banfield, director of the Seventh-day Adventist Office of Human Relations and general conference field secretary, said, "The statement when it first came out shocked a lot of people. It haunted us all the way down to now."

"We took this statement as an offense to black people," said Donald George Morgan, president of the International Layman's Action Committee for Concerned Adventists, a 300-member group of black and minority church members. Members of the group picketed the church meeting last week.

"At least for a while it the apology heals this wound, but in terms of healing the racism it doesn't, because racism is a cancerous thing in the church," Morgan said yesterday. "It's there, and it will come out again in different form."

In a telephone interview yesterday, Mittleider said, "Morgan championed this thing on his own. If an individual wants to picket that's fine -- that's one of the great things about our society, freedom of speech."

Banfield said yesterday, "Churches are going to have to learn to live with this openness: There's nothing private anymore, and we're going to have to give an accounting of ourselves publicly -- and that's not all bad."