The Prince George's County Board of Education accepted the resignation yesterday of Superintendent John A. Murphy, freeing him to take a similar job in Charlotte, N.C., after the current school year ends in June.

The school board's action came less than 24 hours after Murphy, who has been credited with improving the image and morale of the Prince George's schools during his nearly seven-year tenure, was offered the top education post in the Charlotte-Mecklenburg school system.

Murphy said that although he would accept the Charlotte job if the Prince George's school board agreed to free him from his contract, the move to North Carolina will not be made final until after his attorney reviews a proposed agreement with the Charlotte school board.

Murphy's contract in Prince George's would have expired in June 1992. His starting annual salary in Charlotte will be $144,000, $24,000 more than he makes now.

The board's vote to allow Murphy to leave Prince George's a year ahead of schedule was unanimous.

After the vote, board Chairwoman Catherine M. Burch read a statement praising Murphy. "He believed we could build equity and excellence into our school system, and he said at the outset that we were going to become a national model for education in America," Burch said, choking back tears. "He was right. We are."

The administrators and parents at the meeting then gave Murphy a standing ovation.

At a news conference yesterday, Murphy, 55, said he was extremely saddened about leaving, but said Prince George's could not offer him the job security he is seeking.

Murphy also criticized the county's legislative delegation for its unwillingness to exempt the county last year from a state law that limits school superintendents' terms to four years. Last February, the school board tried to prevent Murphy from accepting a job in Florida by offering him a 10-year contract with a $150,000 annual salary, but a community furor ensued over the length of the contract and state lawmakers refused to approve the salary package.

Murphy said the county NAACP's vocal criticism of him was also a factor in his decision, adding that he does not believe the group speaks for a majority of black residents in the county.

He also said his leaving was not because of the mounting financial problems that the local school system is facing. "We have responded to a lot more serious problems than this one," he said.

Earlier in the day, several school board members said they saw no point in trying to keep Murphy in Prince George's against his wishes, while expressing regret over his departure and concern over the task of finding a successor.

"Charlotte's lucky -- I just wish we were Charlotte right now," said board member Marcy C. Canavan. "It's not the best time for a superintendent search."

Murphy's decision to leave Prince George's puts the county in the position of having to compete with nearly two dozen other large school districts in the nation that are looking for superintendents in a shrinking pool of qualified applicants.

His departure also comes at a time when the county and state are experiencing serious financial problems that could make it more difficult to attract the best candidates, observers said.

Board Chairwoman Burch said the board will hold two public hearings to gather public opinion about how the search for a new superintendent should proceed, as well as recommendations on the qualities that parents and community leaders think the new superintendent should have.

The hearings will begin at 7 p.m. and will be held Feb. 18 at Friendly High School in Fort Washington and Feb. 20 at Eleanor Roosevelt High School in Greenbelt.

Several observers said they expect considerable support for black candidates to lead a county school system whose enrollment is 65.3 percent black and growing. Prince George's has had no black school superintendents.

"I think it is incumbent upon the leaders of our diverse community to pursue a unified and nationwide search for a very qualified successor," said Wayne C. Curry, the chairman of a school committee on black male achievement. "In that search, among other things, they should see about the availability of an African American who ought to be seriously considered."

Alvin Thornton, a Howard University professor who sits on a committee that monitors school desegregation efforts in Prince George's, put it another way. Thornton said it was insulting for people to question a desire for a black superintendent.

"What I think the black community is saying is first, we want quality education for our children," Thornton said. "Second, we want the necessary funding to bring that about.

"Once you get that in place, you say of course, it's obvious that a school system that is 65 percent black would expect every effort to be made to find a black school superintendent," Thornton added. "If the tables were turned, it wouldn't even be debated."

Curry and Thornton praised Murphy for his success in boosting student test scores, securing support from the county's business community, and pushing for higher expectations of minority children.

But they cautioned against expecting a new superintendent to achieve miracles. Some residents made that mistake with Murphy and became discontented with him as a result, a factor that probably contributed to Murphy's decision to leave, Thornton said.