Officials of the National NAACP have decided to reopen a federal desegregation suit against the Prince George's County school board unless the board can show within the next 10 days that a modified busing plan approved last month won't result in further segregating the county schools.

NAACP general counsel Tom Atkins said this week that his office will not make a final decision to reopen the desegregation suit filed in 1972 by the Prince George's NAACP until it receives the information it has requested from the school board.

Specifically, the NAACP has asked the board to supply documentation of the racial composition of student bodies and faculty in individual schools, curricular offerings, the effect of past and future school closings and other such items.

"We have a range of concerns, all of which will require information," Atkins said.

Josie Bass, president of the Prince George's NAACP, said yesterday that the request for information is "a good faith attempt by us to make sure we have covered every avenue and secure all documentation prior to taking court action."

The national office became involved again in the emotional and highly complex county busing issue at the request of the Prince George's branch after the school board voted in May to reduce busing by returning some 3,600 elementary school children to neighborhood schools.

The county NAACP chapter has long felt that the school board has tried to thwart the federal court's desegregation order, by attempting to reduce busing and by school closings.

When the board finally adopted a modified busing plan after a dozen previous efforts had failed because of internal board politics, local NAACP members charged that the plan would further resegregate the county school system and cause schools in predominantly black areas to be closed in the future.

Since last month, NAACP members have been working quietly to document their case. The national office's request for further information, which was sent to the board yesterday, apparently is part of that effort.

Atkins said he expects the board to go along with his request. If it does not, he will ask U.S. District Court Judge Frank Kaufman of Baltimore to reopen the 1972 case.

"I would go to court in a minute at either the slightest hint of refusal to supply information or to supply it in a timely fashion -- immediately," Atkins said.

Paul Nussbaum, the school board's attorney, said yesterday that the NAACP will be provided with any information already available to the public. Dissemination of any other information will have to be approved first by the board.

School board chairman JoAnn Bell said yesterday, "I see no problem in our answering their request. Obviously we feel that we are in full compliance with the law and the plan we approved [in May] is defensible in court."

The May modification vote by the board and the national NAACP's recent reinvolvement in the eight-year-old issue indicate that the controversy over busing is far from over in the county.

Since Judge Kaufman first declared that Prince George's had failed to follow Supreme Court desegregation rulings and ordered what was then the largest busing plan in the country, opponents blamed busing for the loss of affluent families and businesses.

Since busing began in January 1973, both the county and the schools have seen a large increase in black population. Percentage of black students has risen from about 24 percent to about 50 percent today.

Although the county began to change racially, the busing plan never was altered to reflect that change.

As a result, busing patterns designed in 1972 to desegregate schools in many cases no longer accomplish that purpose. In adopting the May modification the school board said it was altering the busing plan to eliminate "unnecessary busing," the busing of children from one integrated area to an integrated school or from a black area to a predominantly black school.

Judge Kaufman's order was designed to eliminate black majorities in 46 of the country's public schools. After an initial decline, the number has been increasing to the point that last fall 108 -- or almost half -- of the county schools were more than 50 percent black.