Third superintendent candidate withdraws

Mary Grassa O'Neill , former superintendent of Milton schools, has become the third candidate to drop off the short list to become the new chief of Boston Public Schools.

The pullout plunges the hunt for a new superintendent, which is already behind schedule, into uncertainty. The two contenders still in the running to succeed Thomas W. Payzant are high-ranking school system officials but have never served as superintendents.

Members of the search committee previously said if more than one of the five leading contenders pulled out of the running, the search would be expanded to recruit other candidates. Yesterday, a school committee spokesman declined to say whether an effort to attract new candidates is underway. Superintendent Payzant retired last Friday.

Grassa O'Neill said she was honored but has decided to stay at Harvard Graduate School of Education, where she runs a center that trains school principals. Manuel J. Rivera , superintendent of Rochester, N.Y., and former San Francisco Superintendent Arlene Ackerman have also dropped out of the running.

``After much thought and consideration I have decided that I am happy where I am," said Grassa O'Neill in an e-mail she sent Saturday. She did not return phone calls yesterday.

Elizabeth Reilinger , Boston School Committee chairwoman and co-chairwoman of the search committee, did not return telephone messages yesterday. In March she said the city was on track to name finalists as early as April and select a new superintendent in June.

Boston schools spokesman Jonathan Palumbo said that search committee members are still talking to candidates but he would not provide more details. Boston has not officially announced the names of the top contenders for the job; sources familiar with the search provided them to the Globe last Monday.

``Clearly it would be great to have somebody in place as quickly as possible," said Palumbo. ``But they're not going to sacrifice finding the best person to meet deadlines that we set for ourselves."

Last week the School Committee installed Michael Contompasis , the district's chief operating officer, as interim superintendent.

Another wrinkle is the popularity of Rivera, and questions surrounding his availability. Rivera said last week that he would not proceed to the final round of consideration, and that he had merely come to Boston to help advise those searching for a superintendent. But Rivera was a favorite of many search committee members, sources familiar with the search have said. And one source said that they expect Boston to continue courting Rivera, who was the 2006 national superintendent of the year.

Rivera did not return calls yesterday.

Still in the running are Nancy J. McGinley , chief academic officer for Charleston County schools in South Carolina, and Deborah Sims , chief of K-12 operations in San Francisco.

McGinley said it is normal for search processes to take time. She said she hadn't heard when the interviews would take place in Boston, but is still willing to go through them.

``My position hasn't changed," McGinley said yesterday. ``I'm certainly still as interested as I was last week."

Sims did not respond to telephone messages.

Tracy Jan of the Globe staff contributed to this report.