Possible listing candidate Napier Port said the cost of its planned new wharf development - 6 Wharf - had gone up to $170-$190 million from last year's estimate of $142m.
The port's owner, the Hawke's Bay Regional Council, said the increase reinforced the need for external capital at the facility.
The council said it expects to make a final decision on the 33 to 45 per cent partial float of the port in six to eight weeks.
A report to the council last year said the port needed $320-$350m over 10 years for it to support the growing Hawke's Bay economy.
About half of that cost was for the construction of the new wharf.