Analysts say investors may be reluctant to take a stake in the float of another State energy company at the moment.
Mighty River Power's share price has fallen 11% since it floated at $2.50 early last month.
The Government plans to part-privatise Meridian Energy by the end of the year and analysts say would-be investors will be reluctant to buy if the current market conditions persist.
But Milford Asset Management executive director Brian Gaynor said a strong annual earnings results from Mighty River in August and a rebound in share prices could restore confidence in the sales programme.
Radio New Zealand's economics correspondent says global market conditions have certainly changed since the heady times of early May.
Uncertainty about the ability of the US economy to function without central bank aid has rattled investors, along with concerns about growth in Europe and China.