Dredging Wellington harbour and other developments would not force CentrePort to be partly privatised, it says.
The company is majority-owned by Greater Wellington Regional Council, with Horizons Council as a minority shareholder.
Rumours of a partial sale of the company to fund developments have been sweeping Wellington.
But chairman Warren Larsen said the port could pay for its own development without selling a stake.
"All the capital that we have ... in terms of investment requirements can be funded from revenue and from debt financing if we have to extend that," he said.
Mr Larsen said it would cost up to $40 million to dredge and deepen the harbour entrance by three metres, which would double the capacity of visiting container ships.
Resource consent for the dredging would be sought this year.