More than 400,000 people have now pre-registered their interest in buying Mighty River Power shares.
Tony Ryall, minister for state-owned enterprises, said the pre-registration website and the 0800 call centre had been extremely busy since the pre-registration programme was launched.
People who pre-register can received up to 25 per cent more shares if the offer is oversubscribed. All New Zealand individual investors are guaranteed $2000 worth.
The pre-registration process closes on Friday at 5pm.
Ryall urged those who were interested to go to the government's website before the close-off deadline.
"We encourage New Zealanders who are interested in finding out more about the Mighty River Power Share Offer to pre-register their interest. Pre-registering does not oblige you to apply for shares and will allow us to keep you informed."
The investment offer document is expected to be available mid-April ahead of a May listing.
The Government is selling up to 49 per cent of Mighty River Power.
Infographic: Claudia Ruiz