Insurance Australia Group has completed its $380 million purchase of AMI, after the Reserve Bank provided the final regulatory clearance.
As part of a deal announced last year, IAG will take over almost 500,000 customers from AMI.
But it doesn't want $1.8 billion worth of claims relating to the Canterbury earthquakes, so the Crown is taking ownership of them.
The Overseas Investment Office and the Commerce Commission previously approved the deal and the Reserve Bank has now granted the new AMI a full insurance license.
Meanwhile the rump of AMI held by the Government has been issued a credit rating of A-.
The AM Best ratings agency says the creditworthiness of the renamed Southern Response Earthquake Services reflects the expected improvement in its capitalization, its expected reduction in underwriting risk as well as continued government support.
The new AMI also has a rating of A-.