BOSTON - In fewer than six weeks, the changes brought by the new Catholic archbishop of Boston have been less evolutionary than revolutionary.

Archbishop Sean P. O'Malley has eschewed lavish vestments, favoring a friar's robe and sandals. He spoke Spanish, Portuguese and Creole at his installation, to reflect the shifting demographics of his new community. He has shunned the mansion that housed his predecessor, Cardinal Bernard F. Law, who was perceived by many as aloof and unresponsive to the emerging sexual abuse scandal. And he met with abuse victims and made sure the church paid for their counseling.

But the most dramatic change came Tuesday, when, after an 18-month stalemate, O'Malley delivered a record-setting $85 million agreement between the church and 552 abuse victims. Those involved in the talks cited two key shifts in the church's approach to negotiations under O'Malley's leadership: He attended a session last Sunday in which the outlines of the deal were hammered out. And days after his arrival in Boston, he brought in key players from an abuse case he had helped settle a decade ago, including mediator Paul Finn and lawyer Thomas Hannigan.

Victims' attorneys said the new team restored trust to a process that had become embittered, and helped solve several sticking points in the days leading up to Tuesday's agreement.

"In the end, it was about personal relationships. The changing of the guard, and especially Tom Hannigan's presence, meant everything," said Roderick MacLeish Jr., who has known Hannigan, Finn and O'Malley since 1992, when they settled more than 100 abuse suits in the diocese in Fall River, Mass. Last year, MacLeish, Hannigan and Finn settled a case against Jesuit priests at Boston College High School.

Indeed, beyond O'Malley's personal involvement, his most significant change in dealing with the victims may have been bringing in Hannigan. MacLeish and his colleagues were unanimous in their praise for the lawyer, a 51-year-old Catholic. Described as soft-spoken and fair, he replaced lawyers known for hardball tactics.

"Tom is somebody who, while a consummate professional, is also very embarrassed by all of the attention directed at him," said John Montgomery, a partner with Hannigan at the Boston firm Ropes & Gray. "He's never one who would seek self-aggrandizement, particularly at the expense of a client or a colleague. It makes him a very effective negotiator."

Victims' attorneys said negotiations were expedited because they trusted Hannigan and he trusted them. The church originally had asked to pay a settlement in installments ending in 2005, which MacLeish called a potential "deal-breaker." Hannigan also made a request.

"He told us that the amount of money we were asking for was unacceptable to the church," said MacLeish. "I knew if he said it that it was true and he knew our demands were not just a negotiating tactic."

The final agreement calls for the settlement to be paid in a lump sum by Christmas.

With the details worked out, negotiations focused on church finances. Under Law, who resigned because of the scandal, the archdiocese last year had agreed to a $20 million-to-$30 million settlement in another abuse case. But it later said it could not afford that much, and eventually paid $10 million.

This time, Hannigan made clear that the committee that oversees church finances had already voted to approve the agreement, victims' attorneys said. "I took Tom aside in the hallway and said, 'Have you personally looked at how they're going to pay this?' And he said, 'You have my assurance,' " MacLeish said. "I have known him for 10 years, and everything he's said has come true. If anyone had said that other than Tom, I don't know."

The church hopes to raise $15 million by selling property, a spokesman said. O'Malley told the Associated Press that the archdiocese will also take out loans and try to collect money from its insurance companies, but will not use collection money from parishioners. He also suggested the church may sell or mortgage more properties.

Attorneys on the case estimated that their total fees could approach $30 million.

The quick and relatively amicable negotiations that unfolded over the past few weeks in Boston could provide a model nationwide. Abuse settlements were reached recently in Kentucky and Rhode Island, but cases are still pending in California, Wisconsin and elsewhere.

"There are differences between the two situations, but hopefully some of the goodwill generated there will translate into progress out here," said Raymond Boucher, lead counsel for more than 400 plaintiffs in Southern California.

Jeffrey R. Anderson of St. Paul, Minn., who has represented hundreds of alleged victims in other dioceses, noted the speed with which O'Malley produced a settlement. "It proves these guys can do it, if they want to," he said. "If O'Malley could do it in five weeks, shame on every other bishop and every other diocese that doesn't do it in five weeks."