Looking back over his time with Pan Pac, Ducker said he had seen tremendous change in the company over the past 45 years.
"I have been fortunate to work with excellent people from our staff through to our suppliers, contractors, shareholders, iwi and the wider community," Ducker said.
"The time now feels right to pass on my corporate responsibilities and to explore new projects involving family and friends."
Tony Clifford, general manager – pulp, has been appointed managing director effective February 1.
Clifford has been with Pan Pac for 27 years. Initially employed as an electrical engineer, he has held technical and managerial roles within the company and has been a member of the executive management group for 15 years.
Clifford has overseen a $70m upgrade of the pulp mill and the development of markets for BCTMP (pulp) into Asia and beyond.
Pan Pac Forest Products Limited (Pan Pac) was established in 1971 as a joint venture between Carter Consolidated (the predecessor of Carter Holt Harvey Limited), Oji Paper Company Limited and Kokusaku Pulp Company Limited.
In 1993, the company became wholly Japanese owned by Oji Paper and Nippon Paper Industries, the two largest pulp and paper producers in Japan.
Pan Pac retains tree ownership for around 35,000ha and supports the harvest and utilisation of over 1.5 million tonnes of logs. Pan Pac operates one of New Zealand's largest sawmills at Whirinaki, with a lumber output of around 500,000cu m per annum.
The company exports lumber to 17 countries and in 2016, Pan Pac established a second sawmill in Milton, Otago, that currently produces 100,000cu m per annum.