The cash will be used to reinvest in new or enhanced public space, possibly at the foot of Lower Albert St or at the Admiralty Steps, east of Queens Wharf, which are in Ports of Auckland ownership.
The shaded and windswept nature of Queen Elizabeth Square were put forward by council officers as a strong reason for selling the civic space, which was created in the 1970s and become a gathering place for protests and marches up Queen St.
Said councillor Ross Clow: "This is a dead end public space."
It is also the "best piece of land in Auckland", according to a senior commercial real estate expert, who said it had a commercial value of between $20,000sq m and $30,000sq m, or even higher.
The expert said a recent land transaction in Shortland St was valued at $16,000sq m, but Queen Elizabeth Square was a better piece of land.
Waitemata councillor Mike Lee said by "approving in principle" the sale of the square, the council was giving a "blank cheque" to a major commercial project driven by a major offshore multi-national.
Precinct's management is jointly owned by Australia's AMP Capital and Middle Eastern interests in Abu Dhabi, which also own 19 per cent of the company's shares.
North Shore councillor Chris Darby said the council was dealing with the downtown area in "bite sizes" without explaining the broader context for Queen Elizabeth Square, Queens Wharf, Quay St and planned new bus interchanges.
A report to councillors did not include any context from the city centre integration group (CCIG), a new bureaucracy set up to co-ordinate and focus activities on the waterfront and downtown Auckland, nor was its chief executive Rick Walden present to answer questions.
North Shore councillor George Wood said he could not support any sale until he saw details on the proposed bus interchanges at Britomart and Lower Albert St, and Statutory Maori Board member Liane Ngamane said it was ancestral land and mana whenua had not been part of the decision.
Councillor John Watson said much had been made about the state of Queen Elizabeth Square, but there was a total lack of analysis about the value of the land and how to make it successful.
Staff have been instructed to work with the Waitemata Local Board and iwi on evaluating 'offsite' public civic space options with the findings to go to the parks, recreation and sports committee for approval in August.
Precinct Properties plans to lodge a resource consent later in the year with a view to completing work, including underground provision for the City Rail Link, in 2017.