Auckland Council has given the go-ahead for St Lukes shopping mall to double in size, making it the largest in the country.
The council accepted the decision of independent planning commissioners to allow Westfield to expand the centre.
Councillors were divided over the merits of the expansion, in what some said is an already busy area.
Mayor Len Brown persuaded a majority to back a plan for mediation between Westfield and the community to address concerns about traffic and urban design.
The residents association says it will appeal against the decision at the Environment Court.