State-owned enterprise minister Tony Ryall said advertising spend for the two floats was comparable.
A report on total costs associated with the Government's mixed ownership model shows it cost just under $41 million to list Mighty River Power on the sharemarket.
Of that the Government paid $28 million and Mighty River shelled out $12.8 million.
Total spending for the programme hit $58.9 million as of June 30 of which $41.1 million was paid by the Treasury and $17.8 million was paid by the four energy companies.
That does not include the $30 million sweetener the Government agreed to pay to New Zealand Aluminium Smelters to help seal contract negotiations for the Tiwai Point smelter in August.
The deal was seen as essential in preparing the way for Meridian Energy's sharemarket float.
The Government initially said it hoped to raise between $5 billion and $7 billion from the mixed ownership model programme but this week Prime Minister John Key said it was more likely to be closer to $5 billion.
Meridian Energy is expected to list on October 29.
How much energy companies have spent preparing for share market floats (to June 30)
Mighty River Power $12.828m
Meridian Energy $3.484m
Genesis $1.344m
Solid Energy $0.172m