Contact Energy has raised about $332 million from shareholders to fund the building of new generation plant.
The power firm had hoped to raise about $350 million by offering investors one share for every nine held at $5.95 each.
Nearly 95% of investors, including 52% shareholder Origin Energy, took up the offer.
Contact will issue an extra 66 million shares.
The remaining shares will be offered to larger investors through a book building process.
The money will be used to build the 166 megawatt Te Mihi geothermal power station north of Taupo, which due to be completed by mid-2013.
