Mighty River Power has lifted its earnings guidance, as it pushes back planned maintenance on its hydro and geothermal plants.
It's the second time the State-owned power generator has issued an earnings upgrade this year.
In March, Mighty River Power lifted its full year earnings guidance from $391 million to between $420 million to $435 million because of strong half year results and a postive outlook.
It's now lifted that forecast again and expects to generate earnings of between $435 million to $450 million.
Chief financial officer William Meek says the increased earnings will be due to decisions to defer maintenance on some of its geothermal fields and hydro plans until the next financial year.
Mr Meek says other parts of its business also made positive gains which will help the bottom line.