The Roman Catholic Diocese of Helena filed for bankruptcy protection on Friday as part of a proposed $15 million settlement for hundreds of victims who say clergy members sexually abused them over decades while the church covered it up. Dan Bartleson, a spokesman for the diocese, said the Chapter 11 bankruptcy reorganization plan came after confidential mediation sessions with the plaintiffs’ lawyers and insurers, resulting in the deal to resolve the abuse claims. Federal Bankruptcy Court in Montana would be responsible for approving and supervising the disbursement of $15 million to compensate the 362 victims identified in two lawsuits, and at least $2.5 million will be set aside for others who come forward, Mr. Bartleson said. The church expects to pay that $2.5 million, with the rest to be paid by insurers, he said. It does not expect to have to liquidate assets or close programs, he said.