Auckland Council's investments grew by more than $1 billion in the past four years, bolstered by its port and airport holdings.
New figures show the value of the council's key investments have increased by more than two thirds since 2010 from $1.5 billion to $2.5 billion.
The Ports of Auckland is now worth more than $1 billion, a 75 percent increase in four years.
The council's 22 percent shareholding in Auckland International Airport Ltd is valued at $1.1 billion, a rise of 81 percent.
Auckland Council Investments chief executive Gary Swift said all of the council's major financial assets have gained in value.
Since it was set up in 2010, Auckland Council Investments has returned dividends of $88 million.
It is planning a further dividend payment of $156 million before the end of June this year, three times more than budgeted.