The leading candidate to run the District's troubled school system abruptly withdrew from consideration yesterday, leaving city officials without a viable contender for superintendent more than seven months after the job became vacant.

Carl A. Cohn had been personally wooed by Mayor Anthony A. Williams (D), who abandoned his quest for control over the school system during early negotiations with Cohn. City officials also agreed to pursue the former superintendent of Long Beach, Calif., even after he said he would accept only a one-year contract.

But, in the end, neither the wooing nor the concessions proved sufficient, reaffirming how difficult it is to recruit a top-flight educator to lead the 64,200-student system. The District's first choice, former New York City schools chancellor Rudolph F. Crew, turned down a compensation package of as much as $600,000 and instead accepted the superintendent's job in Miami-Dade County.

Addressing the needs of the school system is an enormous challenge for a superintendent and is often cited as a top priority by Williams. Test scores are among the lowest in the country, and four superintendents in the past eight years have not solved long-standing problems.

Although city officials all agree on the need to attract an accomplished leader for the school system, the mayor, the council and the school board have often been at odds. Williams, who in September proposed taking control over the system from the school board, has criticized school leaders for a "history of fiscal mismanagement" and for micromanaging the superintendent.

The school board and the council have had acrimonious debates over the budget, and school leaders have accused Williams of trying to make a power play. The search for a superintendent took place while city leaders were fighting over who would govern the system. Crew and Cohn both said they were concerned about oversight of the school system.

City leaders had hoped to have a superintendent in place by July 1. Instead, the search that unofficially began when Paul L. Vance announced his resignation in November might start anew, and officials are cautioning that the position might not be filled when school begins in September.

Peggy Cooper Cafritz, the president of the school board, said the board will hold a private meeting soon to discuss whether to restart the search or reexamine previous candidates.

Yesterday, a spokesman for Williams said the mayor will consult with the next finalist to determine what type of school oversight system would be preferable, possibly reopening an issue that had been addressed as part of the discussions with Cohn. Williams previously favored a system that would grant him control over the school system, including the authority to hire and fire the superintendent, powers now vested in the school board.

Williams, who was attending a meeting of regional leaders in Richmond, said he was disappointed by Cohn's decision. Without specifying, he alluded to changes that must be made before the city can attract top talent to lead its schools.

"We need to redouble our efforts and leadership of the city to create the conditions for recruiting the very best superintendent," Williams said. "It's all about streamlining oversight . . . and I'm determined to do that any way I know how."

Cohn, now a professor and schools consultant, said in an interview that he decided he could not abandon commitments he had made to his clients on the West Coast. He also said he had second thoughts about whether he would be effective in turning around the school system in a year, a short tenure he had offered in lieu of a permanent job.

"As I looked at this situation, I didn't have the personal courage to go forward," Cohn said. "Typically in the past when I've taken something on, it's been for a long period of time. . . . In other situations, I've tried to stay as long as it took to get the job done. I wasn't ready to do that in this instance."

An education collaborative of seven city and school officials, including the mayor, will meet next week to discuss whether Interim School Superintendent Robert C. Rice should remain in office for the coming school year, said D.C. Council member Kevin P. Chavous (D-Ward 7), who chairs the council's education committee and serves on the collaborative.

There was not enough support among city officials for finalist Candy Lee, a former airline executive, Cafritz said. The other finalist under consideration, Stephen C. Jones, superintendent in Syracuse, N.Y., said he plans to remain in his current job.

Cohn had been endorsed by the collaborative, a panel whose mission was to recommend a finalist to the school board, which makes the final decision. Last week, after receiving the recommendation from the collaborative, the school board voted to enter negotiations with Cohn.

Parent leaders expressed outrage about how the superintendent search has unfolded.

"I'm extremely upset about it," said LeRoy McDonald, president of the PTA at Anacostia Senior High School in Southeast. "It's going just like I thought it would go: disastrous. Everybody knows that they're going to have problems because when it comes down to our school system, no one knows who the real clear-cut leader is. The mayor says it's him. The school board says they're the leaders."

Cecily Darden, a parent activist at Hearst Elementary School in Northwest, said she and her family plan to move to Montgomery County, largely because of problems with the school system. She said the superintendent search has been a continual problem.

"I'm actually saddened by the process," said Darden, who had cooled on Cohn after he insisted on a one-year contract. "We need a long-term commitment."

Cafritz said Cohn's withdrawal was "certainly a setback in terms of timing." She said school board members will find the best candidate for the job and will not "lower our sights. We are not going to make a decision out of desperation."

"I remain very hopeful and optimistic about getting the best superintendent we can find," Cafritz said.

Staff writer Chris L. Jenkins in Richmond contributed to this report.

Carl A. Cohn, former superintendent in Long Beach, Calif., had indicated to District officials that he would take the city's top schools job for a year.