Mayor Nutter yesterday announced a moratorium on all city property reassessments until a new valuation system is put in place.

"It is the only fair thing to do," Nutter said at a City Hall news conference, noting that the freeze had been suggested by Richard Negrin, interim executive director of the Board of Revision of Taxes.

Negrin said that the system currently relies on bad data.

"The data's broken," Negrin said. "That's the primary reason for the moratorium, to fix the data."

Setting up a new equitable assessment system will likely take a year, if not two, officials said. So, tax bills will presumably be frozen through the 2011 tax year. Nutter said that he was not considering a property-tax hike as part of the coming budget cycle.

The only exceptions to the moratorium will be new construction and rehabilitated properties, which Nutter said will still be assessed.

The 18,000 reassessment notices that were sent out last fall can be appealed, Nutter said.

The BRT has come under fire after a series of stories in the Inquirer detailed a culture of patronage, inaccurate assessments and mismanagement at the agency.

The Nutter administration has already taken over the assessment functions of the BRT. And Council passed legislation in December that - if approved by voters in May - would replace the BRT with an assessment body under the mayor's supervision and an independent assessment-appeals board.

Plans also call for shifting the 76 BRT patronage hires who are on the school district payroll to avoid the city rules barring political activity. Nutter has said that this work-around must end.

Human Resources Director Al D'Attilio said civil-service exams would be held on or around March 19 for two classes of jobs at the BRT. Those exams will be open to anyone qualified for the jobs. After the results are tabulated, the BRT will determine how many workers will receive city jobs.