Tournament Parking has made an unsolicited offer to buy the carpark for $75 million, saying the deal could prevent the Council having to sell QE2 Square to help pay for the $2.8 billion rail loop.
The Downtown Carpark was valued at $65 million three years ago.
Len Brown said while the offer is interesting, the Council needs to first decide how it wants to redevelop the area.
He said a new valuation will be done in the next few weeks and if the Council did decide to sell the carpark, it would conduct a tender process