Following a second tender round, which attracted five bids earlier in the month, Mike Elford, of Edinburgh Realty yesterday confirmed the unconditional sale with settlement due late next month.
He understood the building was likely to be the subject of some restoration in the future, but was unable to release further details of the purchaser, who was " a local person and conservator of older buildings".
The BNZ building, which has been the subject of at least two unsuccessful redevelopments, is on a 978sq m site on two titles and has a capital value of $1.5 million, a price for which it is understood to have sold several times.
Embattled Hanover Finance is the second mortgage-holder over the building and had called in a loan against Auckland developer Mike McGurk, prompting the first tender round, but the six tenders were rejected.
The second tender round was forced by first mortgage-holder Crown Money Corporation Ltd, of Auckland, which would have first call on any funds realised, with any remaining funds goingto Hanover Finance.
In 2003, United Kingdom businessman Barry Brookes, who owned the BNZ property for about 10 years, proposed a $4 million project to develop 11 apartments, but found it too difficult to oversee from abroad.
In April 2005, Mr McGurk announced plans to turn the BNZ into a four-to-five star 130-bed hotel and restaurant, worth between $8 million and $10 million.