He is one of the kiwifruit exporter's longest-serving executives, having joined Zespri in Auckland in 1999 as human resources manager. He then helped with the relocation of the head office to Tauranga in 2002 and ascended the company hierarchy, taking the top job in 2008.
Zespri chairman Peter McBride said Mr Jager's record spoke for itself.
"He has helped the business manage the opportunities and challenges which come with growth. Global sales have nearly doubled during his tenure, and value created for growers and shareholders has increased strongly."
NZ Kiwifruit Growers Inc (KGI) chairman Doug Brown praised Mr Jager as a great asset to the industry.
"From a grower perspective, he earned a lot of respect just by his accessibility," said Mr Brown.
"He was always open to speak to growers at any level and I think that endeared him to growers. And he's led us through a number of challenging times. I think under his guidance we're set up for a good future."
KGI chief executive Nikki Johnson described Mr Jager as a world-class leader who had steered the industry through one of the most challenging times in its history.
"His strategic and visionary management style has placed Zespri in a very good position going forward, ready for significant future growth.
"Finding a replacement will be a big job, so KGI is very pleased this time is being taken to find the right person to lead Zespri into the future."
Mr Jager noted that chief executive's tenure was ultimately a board decision.
"We all agree the time is coming and we have now committed to a transition process, which is a healthy one, with a year for the board to handle the recruitment process," he said.
"I think most people would say five-to-seven years is a normal chief executive tenure. I think I've had more than my fair slice of time. The reason for that is I passionately enjoy the industry and am hugely committed and it's been a real privilege to have been in the role."
Chief executive Lain Jager's previous roles at Zespri have included:
• HR Manager
• GM corporate strategy & HR
• GM for grower and government relations
• GM supply chain