OceanaGold, operator of the Macraes gold field, dropped 10 per cent to $2.61 as the price of spot gold fell to a seven-month low.
Contact Energy declined 1.9 per cent to $5.30 after parent Origin Energy posted a 34 per cent drop in first-half profit and Standard & Poor's cut its credit rating to BBB from BBB+.
Summerset Group, the retirement village operator, fell about 2 per cent to $2.49 after the Auckland Council turned down its application to build a new village in Hobsonville.
Auckland International Airport was unchanged at $2.705 after posting an 11 per cent increase in first-half profit.
Port of Tauranga, the nation's busiest export port, rose 0.3 per cent to $13.85 after reporting record first-half earnings on increased volumes.
AMP climbed 2.4 per cent to $6.76 after reporting a 2.3 per cent gain in full-year net profit to A$704 million.
Precinct Properties New Zealand, formerly known as AMP NZ Office, rose 2.4 per cent to $1.05, leading gainers on the NZX 50. The property group this week announced an interim dividend of 2.56 cents from 2.5 cents a year earlier.
Vector rose 0.7 per cent to $2.85 after reporting a 10.8 per cent improvement in tax-paid profit for the six months to December 31 to $118 million in a flat economy.