HARRISBURG — The Pennsylvania Supreme Court on Tuesday appointed Stephen J. McEwen Jr., a senior judge on the Superior Court, to chair the panel that will redraw state House and Senate district boundaries to reflect recent population shifts.

The selection of a chairman for the Legislative Reapportionment Commission landed in the state’s highest court after the House and Senate leaders who are the other members — two Republicans and two Democrats — failed to agree within a timetable set by the state constitution. The justices reached their decision in barely two weeks — well in advance of their May 4 deadline.

“Judge McEwen is widely respected throughout Pennsylvania and the United States,” said Chief Justice Ronald Castille. “This court has full confidence in his ability to lead the reapportionment commission with fairness, lending to the forthcoming task his superb problem-solving skills and keen ability to mediate differences.”

McEwen is the president judge emeritus of the Superior Court — one of two intermediate-level state appellate courts — but his status as a senior judge will be suspended to avoid any conflicts while he serves on the commission, said Tom Darr, the deputy court administrator of the Administrative Office of Pennsylvania Courts.

The state constitution requires that the chairman, who wields the power to break a partisan deadlock, be a Pennsylvania citizen who does not hold a local, state or federal office “to which compensation is attached.” Senior judges are retired judges who work part-time and are paid on a per-diem basis, Darr said.

Castille noted that McEwen is the second consecutive Superior Court senior judge to chair a reapportionment panel. In 2001, the court appointed Senior Judge Frank J. Montemuro Jr.

McEwen, a Republican, is a former Delaware County district attorney who was elected in 1981 to the Superior Court, where he served until his retirement. He also is a former president judge of the Pennsylvania Court of Judicial Discipline.

At least three of the other commission members applauded the appointment.