A majority of the Prince George's County NAACP's executive committee called last night for the "immediate expulsion from office" of county NAACP head William R. Martin, who signed an agreement with county school officials Tuesday to curb school busing.

A statement released by 12 of the 17 committee members asserted that Martin lacked authority to negotiate the agreement and filed to consult; it declared, "We no longer have confidence in our leader."

The agreement that Martin signed with School Board Chairman Norman H. Saunders Tuesday also was cirticized yesterday by national NAACP Chairman Benjamin L. Hooks. Hooks said in a statement released by the NAACP's New York office that the agreement "would reward only those who advocate obstructionism and delay."

Martin, reached early today, said he was not surprised at the call for his ouster. But he said his enthusiasm for the agreement remains high. "There is an urgency and justification for the agreement," he said.

The agreement signed by Martin and Saunders still requires approval from the local NAACP memberdhip and the school board. Some initial reaction from NAACP members indicated that there are fears that the agreement would result in resegregation.

If approved, the agreement could curtail all busing of school children who live in integrated neighborhoods of the county.

The proposal represents a sharp change from the NAACP's past policy of opposing any alteration of the county's court-ordered busing plan, which began in 1973.

Martin and Saunders said yesterday a change in that plan is needed because busing assignment still are based on the raical composition of neighborhoods six years ago.

Since 1973 increasing numbers of blacks have moved into previously all-white communities, resulting in busing patterns that achieve little integration.

The Martin and Saunders agreement would allow children in currently integrated neighborhoods to attend neighborhood schools.

Paul Brock, spokesman for Hooks, said Hooks has not yet seen the agreement, and added that the proposal will be reviewed by the organization's lawyers and members of the NAACP national education committee.

"We're primarily concerned that a local branch has done something that requires approval of the nationl chapten," he said. "We were not consulted in any way."

Brock said Martin's action paralelled that taken in 1972 by the Atlanta NAACP chapter, which agreed with the local school board to curtail some busing in the city in order to reduce municipal spending.

"That action was taken against the national policy of this organization and we suspended that local office." he said. "The same thing could happen in Prince Georges."

During a press conference yesterday, School Board Chairman Saunders defended the proposal, saying that tesegregation would be prevented because of "the checks and balances provided by the NAACP."

"The school board and the NAACP will be involved on all levels to assure equal opportunity for equal and integrated education," he said.

He said eight other members of the board had expressed support for the proposal. A vote by the board is scheduled for March 8, he said.

But Sylvester J. Vaughns, former head of the local NAACP, who brought the original suit that led to the court-ordered busing plan, said, "This thing will not be ratified by the rank and file. We feel left out of the whole process."

Martin said he had "no idea" whether other members would support the agreement or whether NAACP lawyers would either.