State-owned national grid company Transpower's profits jumped $34 million for the December half year to $111.5m, on the back of higher transmission revenues.
Transpower will pay the Crown an interim dividend of $92m in March, down from the previous year's $110m interim dividend.
The profits after tax excluded changes in the the fair value of financial instruments.
Transpower said the higher profits reflected the impact of transmission grid upgrade investments which meant transmission revenue was up strongly to $419.6m, from $344m in the previous corresponding half year.
Transpower commissioned the first of its large capital projects - the North Island Grid Upgrade - at the end of October 2012.
The other two major projects (HVDC Pole 3 upgrade and North Auckland and Northland "NAaN" grid upgrade) are due for commissioning in the 2013 calendar year.
"These projects will result in a more reliable and resilient grid for New Zealanders," Transpower chairman Mark Verbiest said.