Hub may not have school chief till Jan.

Boston officials do not expect to have a new school superintendent in place until next January, after a disappointing and lengthy search in which all but one of five top candidates invited by the city to contend for the job dropped out of the process.

The heads of the committee searching for a replacement for Thomas W. Payzant, who departed last month, will now spend the next several weeks trying to expand the pool of candidates.

School officials had previously hoped to have a superintendent in place by June. Now, the search committee expects to come up with a new list of finalists by the end of the summer and bring them to the city for public interviews in September.

The delay is setting off concern among some observers of the school system, who say that efforts to improve city schools are losing momentum. Others are beginning to ask aloud: Is there something undesirable about working in Boston?

``Given the amount of lead time that was available, it's disappointing we've come down to the 13th hour here without leadership," said Paul Reville, president of the Rennie Center for Education Research and Policy in Cambridge. ``There's a new kind of urgency to this search. The longer the gap between leaders, the more there is a sense of hiatus within the School Department about what's important for the future of the Boston public schools."

The city's inability to pick someone sooner has surprised some education group leaders in the city and around the nation, who say Boston should have had little problem naming a pool of candidates. With the backing of the mayor and an appointed School Committee, the superintendent has been able to run the show. Boston is recognized as one of the top urban school districts in the country, but has room for improvement, said Samuel Tyler , president of the Boston Municipal Research Bureau .

``For those reasons, you would expect candidates to want to come to Boston to make their mark," Tyler said,

So why aren't more candidates clamoring to lead the city's schools? Payzant, who had led the city's schools for 11 years, announced his retirement more than a year in advance.

Arlene Ackerman, the former San Francisco schools superintendent who was one of the contenders for the post in Boston, said she declined to be a finalist for personal reasons, but can see why the city's having a hard time.

It's not Boston, but rather, the timing for top-notch candidates, she said . Those who might be great at the job are happy in their current positions or have recently landed new jobs, said Ackerman, former chairwoman of the Council of Great City Schools. Ackerman will teach at Teachers College at Columbia University this fall.

And then there are the reservations some have about following in the footsteps of Payzant, revered by many in his profession. He established stability in a once politically tumultuous job.

``I see Boston as a golden opportunity," Ackerman said. ``The only thing I've heard is: `God, who wants to follow Tom? He's like a legend in his own time. He's like the godfather of superintendents.' "

The city has been searching for a new schools chief since December, hoping to pick someone before Payzant retired on June 30. The search fell behind schedule, and the search committee settled on naming three to five finalists by the end of June.

The names of the top contenders were not going to be made public until they had agreed to be finalists.

The Globe published a story June 27 naming the five the search committee had chosen.

Subsequently, four have dropped out of the running, including Ackerman; Deborah A. Sims, an associate superintendent in San Francisco and one of Ackerman's protégés; Mary Grassa O'Neill, a former Milton superintendent and former Boston schools administrator who now trains principals at Harvard University; and Manuel J. Rivera, superintendent of Rochester, N.Y., City School District.

Nancy J. McGinley, chief academic officer of Charleston County schools in South Carolina, is the sole remaining candidate from the group of top contenders.

The search committee still ``considers her a strong and credible candidate," said Elizabeth Reilinger, cochairwoman of the search committee and head of the School Committee, in a statement yesterday.

School system officials blame the search's disarray on the Globe's ``premature disclosure of names under consideration," according to a press release from the school system, but only one candidate has indicated that the publicity was a reason for dropping out.

The Globe published the names of the top contenders days before the search committee was due to announce their names. After announcing the finalists, the city planned to bring them to Boston for public meetings.

Sims, the most recent candidate to withdraw, said in an e-mail that she did so because of the uncertainty surrounding the timeline of the search. She did not return phone calls.

Paul Grogan, president of The Boston Foundation, which supports a broad range of activities that boost communities around Greater Boston, said the search committee now should cast a wide net that will bring in nontraditional candidates and consider scrapping public interviews so it can draw the best candidates.

``Consternation is rising around the city," Grogan said.

Tracy Jan can be reached at tjan@globe.com.