Monsignor Lawrence Persico is the vicar general, meaning he's second only to Greensburg Bishop Lawrence Brandt in heading the four-county diocese east of Pittsburgh.
Trautman, who is now 76, sent his mandatory letter of resignation when he turned 75 last year but has continued to lead about 220,000 Roman Catholics in the 13-county Erie diocese in northwestern Pennsylvania.
Persico, who is 61, was ordained in 1977 and has served as a canon lawyer under Brandt and two previous Greensburg bishops, William Connare and Anthony Bosco.
Pope Benedict elevated Persico to monsignor two years ago and he's been vice president of the Pennsylvania Catholic Conference since 2006.
It was not immediately clear when Persico will be installed as Trautman's successor.