Lead managers for the Meridian Energy float say demand for shares in the company from stock brokers has been more than sufficient to allocate 45% of the offer to them ahead of the public offer on Monday.
Stock brokers have been allocated 565 million of the up-to 1.26 billion shares in the company the Government is selling.
Goldman Sachs says brokers' clients may include the full range from mum and dad investors through to sophisticated, habitual investors.
But managing director Andrew Barclay says the guidelines prevented brokers from applying on behalf of fund managers.
He says the decision was made not to allocate more than 45% to this part of the offer.
Mr Barclay says to the extent that retail brokers are unable to satisfy the demand from their clients from the allocation that they have been made they can make further applications from the public pool.
But at this stage the decision has been taken to go no further than 45%.
Mr Barclay says the response from brokers has been particularly strong.