Sir Allen McClay, founder of Northern Ireland-based Almac Group, has died in Philadelphia in the US at the age of 77.
He qualified as a pharmacist in 1953 and established his first business, Galen, in 1968, which he built into a £1bn company.
He retired as president of Galen Holdings in 2001, but soon bought back five divisions and established Almac. Based in Craigavon, County Armagh with other facilities in Scotland, England and the US, Almac became a world-leading pharmaceutical and biotech company with an annual turnover of £167m and employing 2,500 people.
In September last year Sir Allen he assured the future of the Almac Group by establishing the McClay Foundation, a charitable healthcare research trust snd one of the first of its kind in Northern Ireland. The Foundation aims to advance the use of diagnostic tools and drugs in the prevention, control and cure of disease; support and encourage research and innovation in the field of healthcare and allied technologies; increase capacity of all people and specifically those in the developing world to access the latest benefits in healthcare, and to generate and promote employment opportunities for the people of Northern Ireland.
Almac ceo Alan Armstrong said: "On behalf of all the employees at Almac we express our very sincere regret and sorrow at the death of our founder and company chairman Sir Allen McClay.
"Allen was a father figure to every single Almac employee; he often referred to his Almac family and we all shared that view of the organisation he created."