The Montgomery County Board of Education voted last night to review the racial balance policy that the previous board majority, ousted in the November elections, altered in a way that its critics charged curtailed the school system's integration efforts.

The board will begin in May to discuss changes to that part of the policy that defines when there is too high a concentration of minorities in a school and when the board must act to remedy that situation.

The old board's decision two years ago to increase the permissible percentage of minority enrollment at individual schools was generally considered the first step that led toward widespread dissatisfaction with the old board's majority among blacks and civil rights leaders.

Those groups campaigned actively for the four board members who were newly elected last November. Three of those four were present at last night's meeting and were among those who voted for the review.

In addition, the board asked Superintendent Edward Andrews to produce a plan that would require the school system to award a certain percentage of its contracts to minority-owned firms. Last month, the board set aside $25,000 to plan for this program.

"What we're trying to say to the black community is that we believe you have raised very important issues about the education of black students and black involvement," said Board President Blair Ewing. "We are saying we are committed to integrated schools and we want to work with you and not at odds with you. The other board may have said they were committed to integrated schools, but they were never committed to putting that statement into practice."

Under the current racial balance policy, the board is required to consider ways to adjust imbalances in schools where minorities exceed by 40 percent the proportion of minorities in the entire school system. The systemwide proportion is now 25.4 percent, so only those schools with minority enrollments of 65.4 percent or above are affected.

The current policy replaced one that required addressing question of racial imbalance in schools with student bodies more than half minority.

There are now 15 schools with minority enrollments more than 50 percent, and only four that exceed 65 percent.

When the old board instituted the current policy in July 1981, its majority, led by conservative Marian Greenblatt, brushed aside attacks that they were insensitive to the special educational needs of minority children and defended the action as the only reasonable solution in a county that has one area, lower Silver Spring, where the number of minorities has increased dramatically over the past decade.

Greenblatt, who was absent from last night's meeting because of illness, said when reached at home by a reporter: "I don't know what the board is going to do. But I still think that to have any fixed number like 50 percent is absurd." CAPTION: Picture, About 1,000 parents, teachers and students supporting increased funding for public schools demonstrated outside a County Council budget hearing in the Montgomery County Office Building last night after rallying at Richard Montgomery High School in Rockville. They contend the $367 million proposed for schools falls at least $6 million short. By Joel Richardson -- The Washington Post