The District's leading candidate for school superintendent said yesterday that he would not accept a permanent position but would consider a year-long commitment if city and congressional leaders agreed to a number of changes in how schools are overseen.

Carl A. Cohn, who has been personally recruited by Mayor Anthony A. Williams (D), said taking the permanent job would not be "a prudent risk." He also cited family reasons.

His decision is the latest blow to city leaders, who wanted Cohn to sign a long-term contract to lead the 64,200-student system. Last month, their first choice for superintendent, former New York City schools chancellor Rudolph F. Crew, accepted a job in Miami. City officials' plan to have a new superintendent in place by early July -- eight months after Superintendent Paul L. Vance quit -- now appears unlikely.

Yesterday, city officials continued to aggressively recruit Cohn, even as he told them of his concerns and his unwillingness to commit to more than one year. An education "collaborative" of seven city and school officials voted to recommend that the school board open negotiations to hire Cohn, the former school superintendent in Long Beach, Calif.

The D.C. Council last night passed emergency legislation that would extend the current school board structure -- five elected members and four appointed by the mayor -- for four years and then make it an all-elected body. Votes on the final legislation must still be taken. Cohn had said that school governance needed to remain constant for at least four years to ensure stability and attract a top staff.

In an interview yesterday, Cohn said that "a truckload" of other issues need to be resolved by the mayor, the D.C. Council, the school board and Congress before he would take the job and that a "summit" of the leadership should be held. He said they would need to sign a "written compact" agreeing to the changes.

Among other things, Cohn said, the school system's chief financial officer should report to the superintendent and not the city's chief financial officer. He also said that the school system's fiscal year should be adjusted to match the school calendar and that school contracts worth more than $100,000 should not be subject to council approval.

"What's most important is that someone convene a group that talks about what do we need to do to create a bright future for kids in the nation's capital," Cohn said. "And that needs to be the starting point, and everyone needs to be in the room, including the congressional oversight folks."

In the interview, Cohn said that he raised his concerns with Williams in a telephone conversation yesterday and that the mayor said he would work on the issues. Tony Bullock, a spokesman for Williams, said the mayor wanted to accommodate Cohn's concerns.

Cohn said that in a year, he could bring in a "turnaround team" and put in place "the central pillars of support that are needed for teachers and principals." He said that amount of time would also allow him to put in place "a new way of functioning" for the school board and address other oversight issues.

"I think it's real important that someone come in there and fix all aspects of the governance structure so that the long-term, permanent superintendent does not have to do that work," Cohn said.

He said that, for now, "I've ruled out longer than a year." But in the future, he said, he might consider staying longer.

D.C. Council Chairman Linda W. Cropp (D) said that some school systems have had success in bringing in a superintendent on a short-term basis and that doing so could work in the District. She said that negotiations were continuing and that Cohn could ultimately decide to stay longer.

"An individual can come in and change things, do things right and do things correctly and decide that they want to see it through," Cropp said.

She said that Cohn would improve city schools -- on a short-term or a long-term basis.

Peggy Cooper Cafritz, president of the school board, which will hire the next superintendent and negotiate a contract, said she would not comment until the board had made a decision.

Iris Toyer, co-chair of Parents United for the D.C. Public Schools, said that the possibility of hiring Cohn for a year was "outrageous."

"If there is anything this school system needs, it is certainly consistency and stabilization, and you can't get that with someone that's only willing to do that for a year," Toyer said. "The system is too broken."

Some of the issues raised by Cohn have been the subject of previous superintendents' concerns. Crew also said the schools' chief financial officer should report to the superintendent.

Cohn said the changes related to the fiscal year and financial officer are needed to make the school system run smoothly and to ensure accountability. The council's power to approve contracts of more than $100,000 could lead to the superintendent "playing political games," Cohn said.

He said the changes are needed to fix the school system, regardless of who is in charge.

Cohn left the Long Beach school system in 2002 after a decade as superintendent. He now works as a schools consultant and as a professor at the University of Southern California. Williams and other city officials traveled to Long Beach last week to recruit Cohn.