Speaking to the Infrastructure Investment Summit, Transport Minister Chris Bishop said the government was commencing "early market soundings" on the project, and whether it will be a second bridge or a tunnel.
"Many of you will be from countries that have done mega-projects like this. It has been a long, long time since we have," Bishop said.
"We need your thoughts, and the lessons you have learnt being involved in similar projects."
Bishop said the study would also ask about financing options, and expected tolling or road pricing would play a part.
He said the first market sounding would take place in April, with a second one taking place later in the year.
He expected to announce a preferred option in mid-2026.
"Auckland, and New Zealand, needs this project. And after decades of discussion, we are finally ready to put a stake in the ground," he said.
