Mighty River Power shares have hit an all-time low after the company revealed it is losing market share and sales volumes are falling. Its shares were down 1.5 cents at $1.945 at the close of trade on Thursday.
The company is half owned by the Government and was listed on the stock exchange at $2.50 per share last year.
Operational figures from Mighty River show its share of electricity sales fell 2 percent to 16 percent.
Sales volumes also fell 9 percent in the last three months of 2013, though the prices customers paid for electricity rose by 0.6 percent.
A Mighty River spokesperson said volumes fell because residential customers used less power over the unusually warm spring. The company was also choosing to drop low-margin commercial customers in favour of focusing on more profitable clients.
South Island storage lakes were unseasonably full over the quarter, lowering the national wholesale price of power, so Mighty River said it chose to store water at Taupo rather than produce hydro electricity.
A fund manager and executive director at Milford Asset Management, Brian Gaynor, said the fall would be disappointing for investors because the stock has performed badly since listing.
"You're feeling people with Mighty River Power shares are giving up. They've decided they have held on for a while, it looked like the shares were going to bounce up from $2 earlier this month, but they've kept on falling. I think a few retail investors have capitulated today and sold their shares."
However, Mr Gaynor said the drop is in line with the rest of the sharemarket, which has slumped due to fears of interest rates rising in emerging markets like Turkey and South Africa.