The proposed agreement between the Prince George's County School board and the county NAACP to curtail school busing was effectively killed yesterday when a national NAACP committee voted to recommend that the local NAACP president who negoitated the plan be permanently suspended from his post.

The NAACP's Committee on Branches, at a closed meeting in Columbia, S.C., decided to make the recommendation to the NAACP's national board after reviewing the results of a hearing held Monday on the case of suspended president William R. Martin, sources said. The national NAACP board almost certainly will accept the committee's recommendation when it is announced today NAACP officials said.

Josie Bass, the acting president of the Prince George's NAACP, said yesterday that if Martin is permanently suspended by the national board, the local chapter never could even consider the proposed agreement. Martin's suspension would be based, she said, on a finding that the agreement was negotiated improperly because Martin failed to consult NAACP officials.

"This would probably cripple [the agreement] a whole lot," conceded Martin yesterday when informed of the committee's decision.

Meanwhile, school board member Susan B. Bieniasz said yesterday that she has asked Saunders in written memo to explain his role in the negotiations with Martin and to account for the time and money spent by school board employes in secretly negotitating the agreement.

Martin and Saunders initialed the proposed busing plan, known as the "memorandum of principals and understanding," last February after a series of negotiations from which the local NAACP executive board and other members of the school board were excluded.

Since the local NAACP voted to recommend Martin's suspension early in March, Saunders and school board attorney Paul M. Nussbaum have attempted to persuade the black parents who filed the original desegregation suit against the county to publicly approve the memorandum, but those negotiations, too, have failed.

Bieniasz asked Saunders in a letter distributed to all board members, Nussbaum, and county school Superintendent Edward J. Feeney to explain "under what authority" he acted in entering into negotiations and using school staff and "public funds" without ever informing the school board.

Saunders, who has maintained that he was acting within his role as school board chairman, could not be reached yesterday for comment.

The Martin-Saunders memorandum would have allowed communities that have become integrated since the beginning of the county's busing program to petition the school board to stop busing in their areas.

Many local NAACP leaders opposed the plan because, they said, it would result in some county schools becoming all-black.

Bass said that the failure of the Marin-Saunders agreement did not mean that the local NAACP would not discuss possible modifications to the county's 7-year-old court-ordered busing plan.

It is possible, Bass said, that the NAACP might hold a "forum on quality education" from which a new resolution on busing could emerge.

The school board will consider two new plans to reduce busing on May 31, one of them introduced by Saunders as an alternative to his agreement with Martin.

The school board is not required to obtain the approval of the NAACP or any other organization for a busing reduction plan, but Saunders and Nussbaum have maintained that such negotiations are necessary in order to guard against a possible court challenge to a reduction in county busing.

Also contributing to this story was Washington Post Staff Writer Robin Meszoly. CAPTION: Picture, WILLIAM R. MARTIN . . . permanent suspension urged