New Zealand's largest insurer still has to get Reserve Bank clearance before officially taking the reins of AMI.
IAG has bought the troubled Christchurch-based company for $380 million.
It's just been given the green light by the Commerce Commission and Overseas Investment Office, but it still needs a tick from the Reserve Bank.
IAG CEO Jacki Johnson says final approval will bring certainty to AMI's customers and staff.
The agreement excludes AMI's Canterbury quake liabilities, which will be managed by the Government.