Firefighters have spent the night monitoring a blaze near Port of Tauranga's container terminal in Mount Maunganui.
The fire broke out in two palm kernel storage shed about 9am yesterday.
Fire crews battled the blaze throughout yesterday, and four crews have spent the night putting out hot spots.
The palm kernel is expected to be left smouldering for some time before heavy machinery can be used to fully extinguish and remove it.
Port of Tauranga's chief Mark Cairns said he visited the site at 10.30am yesterday and the fire began inside Glencore Grain NZ's southern palm kernel storage shed.
The company had operated on the site for about five years, he said.
"Fortunately, no one was injured which was our first concern, and did not spread to other buildings or pose a risk to the Port's container operations."
The palm kernel was likely to be left smouldering for some time until decisions could be made about what do next, Cairns said.
"While there are various speculations about what may have caused the fire, but that is for the fire investigator to establish," he said.
It took several hours for the fire to be contained and brought under control.
Thirteen fire appliances attended the blaze.