A top Justice Department civil rights official has recommended that his department drop a landmark school-housing discrimination suit against Yonkers, N.Y.

The Yonkers suit was filed last December. It was the first to combine challenges to a city's school and housing practices.

In a July 21 memo that some department lawyers consider insensitive, if not racist, Robert J. D'Agostino, deputy assistant attorney general in the Civil Rights Division, criticized previous department statements about the case.

At one point in the memo to William Bradford Reynolds, head of the Civil Rights Division, D'Agostino disputed a government claim that blacks had been "improperly classified as emotionally disturbed."

"Why improperly?" he asked. He went on to say that "blacks, because of their family, cultural and economic background, are more disruptive in the classroom on the average. It seems they would benefit" from programs for the emotionally disturbed.

At another point he questioned the Justice contention that a "disproportionate number" of minority students were steered to vocational programs and then general high school programs. "Disproportionate to their school achievement?" D'Agostino wrote. "Disproportionate to their needs?"

He attacked the case generally as "the end result of a mind-set in the educational area and one of the opening shots in a new attempt to remake America through coerced residential integration."

D'Agostino also said the suit found segregative intent in virtually any act that didn't lead "to the ultimate good as defined by the Justice Department, racial mixing."

The memo has been circulating in the Civil Rights Division in recent days, and is viewed by several attorneys as the latest sign of the Reagan administration's shift in civil rights enforcement.

One attorney who has read it said, "The general tone of the memo is an insult to black people worldwide." Another called it "outrageous and appalling." A third said D'Agostino's comments "are not appropriate characterizations for someone who does civil rights work."

D'Agostino, 38, a former dean at the Delaware law school and a Reagan campaign aide, defended his memo. "I write a lot of provocative memos," he said in a telephone interview yesterday. "It's one of my jobs around here to get people to take fresh looks at things . . . . One of the reasons Ronald Reagan was elected was that people wanted a fresh look at things."

D'Agostino denied that the memo was racist, although he said he understood how some people might consider it insensitive. He said his academic specialty was bankruptcy law. He has found Civil Rights Division lawyers competent but "committed to a certain point of view," he said. "I think they're wrong on some of those views. I want them to stop and question what they're doing."

The Yonkers case is one of three filed in the final months of the Carter administration that Reynolds is reviewing to determine whether they should be continued. No decision has been reached on the Yonkers case.

Yonkers, north of New York City in Westchester County, has a population of about 200,000. Its school system has approximately 23,000 students, 32 percent of whom are black or Hispanic.

The Justice suit said the local school board, city officials and the local community development agency discriminated against minorities by a pattern of school construction and closings, alteration of attendance lines, assignment of teachers and selection of sites for subsidized housing in heavily minority areas.

D'Agostino criticized the department's housing allegations by noting that Yonkers had built subsidized housing on sites approved by the Department of Housing and Urban Development. "What is the nature of Yonkers' violation? They were stupid enough or altruistic enough to voluntarily participate . . . ," he said.

D'Agostino concluded his memo by saying, "I see absolutely no reason to pursue this case in its present form. If it is the Reagan administration's position to attempt to create law that will mandate the building of low-income housing projects when communities do not want such projects, then we should proceed; otherwise we should not."