Archbishop Charles J. Chaput, in a pastoral letter to be read Sunday, is warning the region's Roman Catholics that 2012 could be a "painful" year for the Archdiocese of Philadelphia, marked by school and parish closings, a bruising sex-abuse trial, and tough decisions on the status of dozens of priests accused of misconduct with minors.

A blue-ribbon panel appointed to study the needs of archdiocesan schools will issue its report in January and "likely counsel that some, and perhaps many, schools must close or combine," Chaput wrote in his two-page letter, which is to be read aloud at all parishes.

"The archdiocese remains strongly committed to the work of Catholic education," he continued, but "that mission is badly served by trying to sustain unsustainable schools."

He also said he expects to decide in "the first months" of the new year which of 27 priests under investigation for suspected misconduct with minors should be restored to ministry, and which will permanently removed.

The priests were suspended in March after a Philadelphia grand jury said 37 archdiocesan priests in active ministry had unresolved misconduct accusations against them. A team appointed by the archdiocese concluded that about 10 of the charges were frivolous, and is investigating the others.

"To whatever degree complacency and pride once had a home in our local church," Chaput wrote, "events in the coming year will burn them out. The process will be painful," he warned, but the goal is to "restore the joy and zeal of our discipleship."

The letter was dated Thursday, the Feast of the Immaculate Conception, which also marked the third month since his installation as archbishop.

Chaput was in Rome on Friday for a meeting with Pope Benedict XVI and unavailable to discuss the letter, a copy of which The Inquirer obtained.

Over the next 18 months, the letter says, the "same careful scrutiny" applied by the schools panel must also be directed towards the archdiocese's 266 parishes, and to operational budgets as well.

"Honest scrutiny can be painful," Chaput wrote, "because real change is rarely easy."

"These are not simply business issues," the letter cautions. "They go to the heart of our ability to carry out our Catholic ministries."

Chaput also touched on the impending trial of three current and former priests and a former parish schoolteacher on child sexual assault charges.

On trial with them will be Msgr. William Lynn, the archdiocese's former secretary for clergy and one of the highest-ranking church officials charged to date in the priesthood sex abuse scandal. He is accused of child endangerment for his alleged role in assigning known sex abusers to parishes.

Chaput warned that a "harsh media environment" will likely surround the trial, adding to the shame and public anger that "many innocent priests" have borne since the grand jury report was issued in February.

Chaput's letter speaks also of the archdiocese's "grave and continuing obligation to help victims of clergy sex abuse to heal." It was not clear if a later reference to his determination to "defend" the archdiocese's "limited resources" was a pledge to resist expanded right-to-sue legislation for adults molested as children.

The 17-member school study panel was appointed a year ago by Chaput's predecessor, Cardinal Justin Rigali. Archdiocesan schools were at a "crossroads," Rigali said then, because of "changing demographics, declining enrollment, and a struggle to keep [education] affordable."

Composed mostly of business leaders and educators, the panel was charged with crafting a plan "to assure the sustainability of Catholic education" that takes into account "demographics, staffing, facilities, and financing." Its report was originally projected for September.

The archdiocesan school system educates 49,000 youngsters at 156 parish schools and 16,000 students at 17 high schools.

There were 167 parish schools when Rigali appointed the panel a year ago, and 211 a decade ago. In 1965, a record 208,000 youngsters attended Catholic schools in the archdiocese.

The archdiocese claims about 1.5 million members in Philadelphia, Bucks, Montgomery, Delaware, and Chester Counties.