BISHOP Noel Treanor is to leave the diocese of Down and Connor to take up a diplomatic post as the Vatican’s ambassador to Brussels.
The Catholic Church said he had been appointed as the Vatican’s apostolic nuncio to the European Union by Pope Francis. He will begin his new role in January, continuing to govern the diocese until a successor is appointed.
A diocese spokesman said "an announcement will be made regarding the pastoral care and governance of the diocese on his departure, pending the appointment of a successor".
Under Pope Francis, previous new appointments have tended to come from outside a diocese.
Bishop Treanor's new post marks a return to the EU as prior to his appointment as Bishop of Down and Connor, he was secretary general of the Commission of the Bishops’ Conference of the EU.
In a letter issued by Bishop Treanor (71) following his appointment, he said he was "honoured", but added that it was with a "heavy heart" he was leaving the diocese.
"I have accepted this appointment and, with God’s grace, I will seek to carry out this mission which has been entrusted to me," he wrote.
"Over the last 14 years, I have served you as Bishop in the Diocese of Down and Connor and it is with a very heavy heart that I take up this new appointment.
"I have so many fond memories of my time here and particularly of all the clergy, religious and the people whom I have met and who have supported me with their advice and expertise. I will always value and consider my time in Down and Connor as a blessing from God.
"I remember and am so grateful for your warm welcome upon my arrival in the diocese. It has been a privilege and a blessing to have been a Bishop with you and for you.
Bishop Treanor (71), who is originally from Monaghan, also said his appointment "comes at a time when the world and the EU, in particular, face great challenges".
"In the midst of war, political and financial instability, conflict and societal change, diplomacy plays a key role in facilitating peace, understanding and goodwill among peoples and nations," he wrote.
"I ask for your continued prayers as I take up this appointment in January.
"I especially invite you to pray for and stand in solidarity with all those who work for peace and the resolution of conflict, protecting human rights and addressing issues of humanitarian need in Europe and throughout the world."
Ordained as a priest in 1976, Bishop Treanor served as curate in the diocese of Clogher and hospital chaplain in Monaghan town.
He has also fulfilled roles of director of adult education in Enniskillen and co-ordinator of the diocesan Assembly of Clergy and was ordained a Bishop in 2008 in St Peter’s Cathedral, Belfast.
He was elected as one of its vice-presidents of Commission of the Bishops' Conferences of the European Union and also serves as President of Justice and Peace Europe.