A report commissioned by the American Civil Liberties Union says the Montgomery County school board has shown little commitment to school integration and that some of its recent school-closing decisions could have a "devastating" effect on integrated neighborhoods.

The 70-page report, which also charged that minority students are bearing the major burden in county school closings, was conducted by The Center for National Policy Review, a Washington-based research institute affiliated with the Catholic University Law School. Copies were given to school board members Monday night.

The center's study found that a majority of schools slated for closure were racially mixed; that is, the schools closed were not those with enrollments that were more than 90 percent white, nor those in which the percentage of minority students was greater than 60 percent. The study said the school board considered racial balance in school closings as a factor only after schools had been screened and after decisions had been made on whether to close or change boundaries.

"The schools which are the most racially isolated, both white and minority, are precisely the schools that will remain open," the report concluded. "In this county, the pattern of school closings tells integrated neighborhoods that only predominantly white or predominantly minority neighborhoods can be certain of keeping their neighborhood schools."

School board president Eleanor Zappone said yesterday the study "does not recognize the fact that this the school closings was primarily a facilities policy to address underenrollment and underutilization.

"This board has had the internal fortitude to face what's needed to be done for a long time," she said. "We just have to face the brickbats when they come."

School board member Blair Ewing, who frequently has clashed with the board's conservative majority over the closing decisions, said the report "will provide the basis, inevitably, for a successful lawsuit against the board."

Edward L. Genn, an attorney who chairs the Montgomery County ACLU, said the ACLU board "has been concerned about the reasonable likelihood that the school board violated its own rules, both procedurally and substantively, with the school closings." He said the report represents the first independent assessment of the board actions.

Genn said a copy of the report has been forwarded to the ACLU's legal counsel for a recommendation as to whether the group should consider any legal action against the board.

The report expressed particular concern about the possibility of resegregation in neighborhoods where a racially mixed school will be closed. "Where racial diversity is a result of neighborhood integration, no attention has been paid to the effect a school closing will have upon the housing patterns," it said. "Frequently, the presence of a successfully integrated school is the keystone to neighborhood stability . . . the effect of a school closing on an integrated neighborhood is particularly devastating."

In the Rosemary Hills area, the report charges, minority students will have to be bused throughout their elementary school years while white students will be able to walk to school. In the Montgomery Blair High School area, the report said, the board's actions have "generally decreased racial balance."