Concord, N.H. ? The Roman Catholic Diocese of Manchester reached an unusual settlement with prosecutors Tuesday, avoiding criminal charges and admitting it probably would have been convicted of failing to protect children from sexually abusive priests.

“The church in New Hampshire fully acknowledges and accepts responsibility for failures in our system that contributed to the endangerment of children,” Bishop John B. McCormack said at a news conference. “We commit ourselves in a public and binding way to address every weakness in our structure.”

The church also agreed to the rare step of giving state prosecutors oversight of its policies, including an annual audit.

Atty. Gen. Philip McLaughlin said he was confident in winning a conviction had the case gone to trial. But he said the settlement does more to achieve his goals of changing the church and making it accountable by releasing thousands of pages of personnel records and other documents after alleged victims’ names are blacked out.

“It speaks for itself when you view it,” McLaughlin said of the documents, already in his possession by court order. “It doesn’t get viewed at all if you’re in a criminal trial.”

The settlement is a new development in the sex abuse crisis that has roiled the U.S. church since January.

Grand juries have indicted individual priests and a grand jury in New York issued a report accusing church officials of sheltering molesters. But the New Hampshire settlement is the only one reached so far under the imminent threat of criminal indictment of a diocese.

State authorities were considering misdemeanors under child endangerment laws, which experts believed would have been the first criminal charges ever against a U.S. diocese. Violations carry fines of up to $20,000 for institutions.

County prosecutors have been working for months on possible criminal charges against individual priests, but virtually all are barred because many years :quot; often decades :quot; have passed since the alleged incidents. Dozens of victims have reached civil settlements totaling about $6 million this year.

Bishop John B. McCormack of the Roman Catholic Diocese of Manchester, second from left, listens as the Rev. Edward Arsenault, chancellor of the diocese, left, answers reporters questions during a news conference in Concord, N.H. The diocese averted unprecedented criminal charges in a settlement Tuesday, admitting that it probably would have been convicted of failing to protect children from sexually abusive priests.

The New Hampshire investigation dated to the 1960s and involved more than 50 priests and more than 100 alleged victims. McLaughlin said he had confirmed reports of molestation involving more than 40 priests and was prepared to bring charges based on five or six of them, involving about 30 victims.

The investigation was triggered by a flood of sexual abuse charges against Boston-area priests beginning late last year. Some of the alleged abuses occurred in New Hampshire or involved priests or victims who had lived in both states at some point.

McCormack figured prominently because he had been a top aide to Boston’s Cardinal Bernard Law before becoming bishop of Manchester in 1998.

The settlement includes provisions to deter future abuse and requires annual audits by prosecutors for five years to ensure compliance. Priests and other employees must follow the state’s mandatory reporting law for suspected child abuse and immediately report suspicions, even if the victim is no longer a minor.

The diocese also must beef up training and education.