Newry, Mourne and Down Council has opened books of condolence for residents to pay tribute to businessman Brian Conlon, who will be laid to rest today.
The Newry man was the founder and chief executive of the technology plc First Derivatives, which has grown to employ 2,400 people and remains based in the city. He died at the weekend after a short illness.
Council chairman Charlie Casey said: "On behalf of Newry, Mourne and Down District Council, I would like to express our collective sadness at the news of First Derivatives founder Brian Conlon's passing. His commitment to this region has improved the lives of the thousands who work for First Derivatives, both here and around the world, and he has played a huge role, not just regenerating the local economy, but also in creating a vibrant and prosperous society for all.
"By creating such a successful financial software company in this region, and importantly, retaining its headquarters in Newry city during years of phenomenal growth, he has put Newry on the map." But he said "the overall emotion is one of sadness for someone who has been taken too young".
"Our thoughts are with Julie, his wife and mother to their two young children, Brian's mother Josephine, sister Kathy and brother Ciaran, the wider family circle and his closest colleagues who have been left devastated by this news," he added.
Mr Casey said the books would be open at council premises in Warrenpoint, Downpatrick, Newry, Ballynahinch, Crossmaglen and Newcastle until August 13.