Aaron Forde, the chief executive of Sligo-based Aurivo, has decided to step down and will leave the business after almost 16 years in his position.
Aurivo is one of the country's biggest co-operatives, with businesses in consumer foods, dairy ingredients, retail stores, animal feeds, and livestock trading.
It has a workforce of about 650 people and exports to almost 50 countries in markets as diverse as Afghanistan, Africa, Central America, Costa Rica, Germany, Iraq and the UK.
In just over a decade, the business has evolved from a largely domestic co-operative to a globally focused business with a milk supply approaching 0.5 billion litres.
"It has been a privilege to lead the Aurivo team and to foster the growth of the business during a time of great opportunity and challenge for the industry. The last 16 years have been some of the most fulfilling of my professional life," Mr Forde said.
"It is the correct time now for me to step down and for a new leader to take Aurivo to the next phase of growth. I wish all in Aurivo continued success and will follow its journey as a successful globally focused agribusiness with interest," he added.