PHILADELPHIA — Msgr. William J. Lynn, the first Roman Catholic Church official in the United States to be convicted of covering up sexual abuses by priests under his supervision, was sentenced Tuesday to three to six years in prison.

“You knew full well what was right, Monsignor Lynn, but you chose wrong,” Judge M. Teresa Sarmina of Common Pleas Court said as she imposed the sentence, which was just short of the maximum of three and a half to seven years. Monsignor Lynn must serve at least three years before he is eligible for parole.

Monsignor Lynn, 61, was found guilty on June 22 of child endangerment after a three-month trial that revealed efforts over decades by the Philadelphia archdiocese to play down accusations of child sexual abuse and avoid scandal. He was acquitted of conspiracy and a second child endangerment charge.

Monsignor Lynn served as secretary for clergy for the 1.5 million-member archdiocese from 1992 to 2004, recommending priest assignments and investigating abuse complaints. During the trial, prosecutors presented evidence that he had shielded predatory priests, sometimes transferring them to unwary parishes, and lied to the public to avoid bad publicity and lawsuits.