More than 50 jobs may be cut at Ports of Auckland, as the company considers automating cranes at its container terminal.
Ports of Auckland said the automated straddle cranes could stack containers higher than at present, allowing 30 percent more containers to be handled in the same space.
However, the switch to the driverless straddle cranes could be more than three years away.
The port management has today been briefing unions on the plan, after alerting them earlier this year to the possibility.
It said more than a quarter of nearly 200 straddle driver positions would be cut if it decided early next year to embark on automation.
The company said it hoped staff turnover and redeployment would minimise the number of workers losing their jobs.