The Super City has earned $391 million from shares in Auckland Airport and Ports of Auckland, which could be sold by the cash-strapped council.
The council's finance committee yesterday voted 16-3 for a review of alternative financing sources, including the possible sale of a $1.4 billion stake in Auckland Airport and the $1.1 billion ports company.
Councillors are taking a wait-and-see approach to a push by senior officers to consider asset sales.
The Herald has reported investors would eagerly snap up any shares with one investment banker, Mark Lister, saying the council's airport stake could be sold in a matter of hours.
Figures supplied to the Herald by the council's investment arm show that dividends from the two assets have totalled $391.6 million in five years.
The airport company has accounted for $231.9 million, including a special dividend of $101.5 million last year.
The dividend from the council's 22.4 per cent stake has gone from $11.8 million in 2011 to $38 million this year.
The 100 per cent council-owned port company has paid out $159.7 million and increased its divided from $10.4 million in 2011 to $54.7 million this year.
Any sell-down of these assets will reduce future revenue and could lead to higher rates to plug the gap.
Finance committee chairwoman Penny Webster yesterday acknowledged everything was on the table for review.
Councillor Cathy Casey asked: "Why would you put libraries in the mix? Why is pensioner housing on the table? This puts the fear of death into me."
The review will also consider $2 billion of Vector power shares held by a consumer trust, which pays an annual dividend to many Aucklanders until the shares are handed to the council in 2073.
Last night, Employers and Manufacturers chief executive Kim Campbell said the city's multi-billion-dollar water system could be another funding source for the council struggling with a massive influx of people, insufficient rates and calls by the Government for Auckland to front up with more money.
Many councillors welcomed the review, including Denise Krum who said the wide scope was exactly what was needed at this stage.
Other councillors, including John Walker, John Watson and Cameron Brewer, said the council would be better off focusing on spending - two days after Local Government Minister Paula Bennett warned councils to look closely at costs.
Mayor Len Brown said he was open to a review and debate on the future of council assets.
He said he would not lead any debate on the sale of shares.
Mr Brown, who has won one Manukau and two Super City mayoral campaigns on a promise not to sell strategic assets, said one or two people initiated those campaigns with the aim of selling assets "but man they changed their minds fast".
The review will be undertaken by two private advisory firms and reported to councillors in November behind closed doors.