Career
On 24 August 1972 Pope Paul VI appointed him bishop of the Eparchy of Cairo for the Maronites. His episcopal ordination was performed on 26 August 1972 by Maronite Patriarch of Antioch Paul Peter Meouchi. His co-consecrators were Nasrallah Boutros Sfeir, Titular bishop of Tarsus dei Maroniti and Archbishop Ignace Abdo Khalifé, Titutar Archbishop of Apamea in Syria dei Maroniti.
As usual in his church, he made his retirement for the completion of his 75th birthday on 5 June 1989.
On 30 March 2006 Emeritus Bishop Merhi died.