A third of Bank of New Zealand's Wellington staff are moving to new offices, but the bank refuses to say if it is abandoning its former home on the waterfront.

BNZ has leased nine floors of Ricoh House in Victoria St, space previously used by rival ANZ.

Previously BNZ's roughly 1100 Wellington staff were all in a single building on Harbour Quays, but the November earthquake saw the building abandoned for the second time in three years due to earthquake damage.

Since then staff have been scattered across a number of buildings across the central business district.

A BNZ spokeswoman would not say how long the Victoria St lease was for. However, two sources said the initial lease was about three years.

Andrew Cotterrell, chief executive of building owner Cornerstone Partners, the owners of Ricoh House said: "BNZ has committed to a lease, having vacated their Harbour Quays building after the November 2016 earthquake."

The bank intended to move in by October, with fit-out "well underway", he said.

Once BNZ staff move into Victoria St, the bank will have its team split between four buildings, which include Customs House on Whitmore St, Co-Operative Bank House on Featherston St, and Spark Central on Willis St.

A spokesman for CentrePort, which owns BNZ's quake-damaged building, said it would make a decision about the property once engineers and insurers had completed assessments. He gave no indication of when those would be completed.

Cotterrell said in addition to BNZ leasing space, Cornerstone also moved in, and Ricoh New Zealand set up a showroom on the ground floor, with some offices above.

"We've transformed the ground floor from what was previously closed-in office space into an open, welcoming retail store, and secured two great tenants who love the location and the opportunity to make the space their own."

Cornerstone Partners spent $10 million refurbishing and strengthening the Victoria St building, which was the largest project undertaken by the firm to date.

Cotterrell was "especially pleased" the building was Cornerstone Partners' new home.

"It provides us with a fantastic permanent location after about five years of moving around to accommodate growing staff numbers.

All 20 buildings in the Cornerstone Partners portfolio had been, or were being, brought up to 100 per cent of new building standard, where possible, he said.

Cornerstone Partners is 50 per cent owned by Wellington property investor Charlie Zheng.