In the first substantial fix for Philadelphia's broken property-tax system in more than a century, the troubled Board of Revision of Taxes agreed yesterday to surrender responsibility for setting tax values.

Mayor Nutter announced that the BRT board had agreed to allow the city finance director to take charge of running the agency and oversee a long-delayed makeover of its tax assessments, widely considered among the least accurate in the nation.

Under the agreement, which takes effect immediately, the board members keep their part-time positions, their $70,000 salaries, and the responsibility for deciding tax appeals.

Also untouched, for now, are the 80 patronage BRT jobs controlled by Philadelphia's Democratic and Republican Party organizations.

City leaders have been debating how to fix the BRT since May, when an Inquirer series described an agency riddled with poor management and political cronyism.

Nutter said yesterday's move was an important first step to restore public confidence and stabilize the agency while he and City Council worked on permanent changes.

His main concern, he said, was a lack of leadership. Executive director Enrico Foglia, a former Democratic committeeman, resigned under pressure last month.

"Someone needs to be in charge," Nutter told reporters at a late-afternoon news conference outside his office. "They don't have an executive director, and their chief assessment officer has been very ill."

In May, Nutter called on all BRT board members to resign, a demand they quickly refused. The new agreement leaves them in office, along with the three-member Board of View, an agency that hears appeals in condemnation cases.

"We have to work with someone," Nutter said yesterday.

The two-page memorandum allows the finance director to run the BRT for six months, though that could be extended to a year.

In the meantime, the BRT will hear appeals from property owners unhappy with their assessments.

Nutter said he first talked with the BRT members in August about splitting the assessment and appeals functions and putting the finance director in charge of operations.

There seemed to be little resistance from the BRT. Yesterday, Nutter thanked them for being "cooperative."

Board members, who have been recessed since July, had nothing to say about the deal. Chairwoman Charlesretta Meade, who has declined to comment about her beleaguered agency for months, did not return phone calls or e-mail messages. Vice chairman Harvey Levin declined to comment.

"The agreement speaks for itself," he said.

City Finance Director Rob Dubow said the administration planned to hire a full-time manager to run the agency under his supervision. The first priority will be to get a handle on the BRT's operations.

"We have a couple people in mind," he said. "We'll hire someone who is a strong manager and can understand what's happening here and how it can be improved."

Dubow also assumes control of what the BRT has called the Actual Value Initiative, a project that would, for the first time, set Philadelphia's property values at their worth in the marketplace.

The agency's assessments are now far off the mark, with nearly identical properties on the same block taxed at dramatically different amounts. Homeowners in pricey neighborhoods pay far less than they should, and owners of lower-income houses pay too much.

But the new numbers still fall far short. The Inquirer has reported on widespread errors in the BRT's first cut, including mistakes in the descriptions of valuable commercial properties whose assessments took sudden and unexplained plunges, sometimes by millions of dollars.

Dubow wouldn't speculate on when the new assessments might be ready.

"We want to do it as quickly as we can, but we want to get it right," he said.

In putting assessments under the control of the Finance Department, Philadelphia is moving toward the structure that most other cities and counties adopted long ago.

The BRT is a holdover from the 19th century: seven members appointed by the city's judges in a process heavily influenced by political leaders. The board positions have been given as plums to party loyalists, a tradition that has long proved impervious to change.

The Inquirer series found an agency in disarray: Political influence pervades hiring and assessments. Values are set according to confusing formulas, with little basis in reality. The board routinely meets in secret, violating state law. Records are a mess, and thousands of properties haven't been reassessed since the 1980s.

The laws that created the BRT are still in force. Nutter and Council members are talking - the mayor said they had a "good conversation" yesterday - but still haven't agreed on how to permanently remake the BRT.

Councilman Bill Green said he was poised to introduce his bill at the Council meeting today. "Council is willing to listen but ready to lead," he said.

Any changes would have to be put to city voters for approval. Nutter said his goal was to sign a law this year and get the charter change on the May ballot.

Nutter and Green think the BRT should be replaced with new agencies, but Nutter thinks he should appoint all the board members. Green thinks Council and the judges should share that power.

Council Majority Whip Marian Tasco said she didn't think Green's legislation was "too far off" from Nutter's goals.

One exception is the BRT patronage clerks and assistants who are kept on the school district payroll, allowing them to remain active in politics. Nutter said all BRT workers should be on the city payroll, but Green's bill would leave them where they are.

"I don't think it's an issue for any of the Council members, just for the mayor," said Tasco, herself a Democratic ward leader.

"I feel very bad for those people," she added. "They've been made to look like the problem with the BRT."

Zachary Stalberg, president of the Committee of Seventy, a civic watchdog group, said the agreement was "a very important first step."

He said, though, that city leaders needed to make the changes permanent. The real goal, he said, should be to remove politics from the BRT's operations by changing the appointments process and scrapping the patronage system.

"I would hate to see it end there," he said. "You don't want to fall back into the old practices once the spotlight is off."

Likewise, Helen Gym of Parents United for Better Education said her group would not be satisfied until the school district - currently struggling with a huge budget deficit - stopped spending $4 million a year to pay the BRT patronage workers.

"They can call it what they want, but it's not reform until the school district employees are on the city payroll," she said. "Obviously, we're still waiting to see when that will happen."