New Zealand shares fell in light trading, with NZX declining on news its chief executive Tim Bennett will leave the stock market operator at the end of the year, while utilities Vector and Contact Energy also dropped.

The S&P/NZX 50 Index decreased 20.02 points, or 0.3 per cent, to 7,352.47. Within the index, 26 stocks declined, 17 rose and seven were unchanged. Turnover was $119 million.

NZX fell as low as 99 cents, ending the day down 1.9 per cent at $1.03. CEO Bennett will leave the stock exchange operator at the end of 2016, earlier than envisaged when he joined the company in 2012, to allow for a new chief to start at the beginning of the financial year. During his four-year tenure, NZX oversaw a jump in listings that coincided with the government's partial privatisation programme, the expansion of a suite of derivative products, and the acquisition of SuperLife and Apteryx to boost the stock exchange's funds management business.

"He's been quite significant, he came in after Mark Weldon and led the business through some significant change," Peter McIntyre, investment adviser at Craigs Investment Partners said. "He was well-respected by the market participants, and the shares have traded on pretty brisk volume today - it's probably seen as a bit of a disappointment to the NZX. He's driven different platforms for the NZX and tried to grow the business outside their core responsibilities, you've seen that with the futures markets that have come into play."


Utilities were sold off today, with Vector leading the index lower, down 2.4 per cent to $3.21, Contact Energy down 1.8 per cent to $4.94, and Mercury NZ dropping 1.6 per cent to $3.01.

"There's may be a move to saying, are we at the bottom of our interest rate cycle? If the Federal Reserve starts moving interest rates up slightly that's typically not good for the long end for bond yields, and utility stocks could face a sell-off from that," McIntyre said.

Sky Network Television was the best performer, up 2.2 per cent to $5.05. A2 Milk Co rose 2.2 per cent to $1.89, Xero gained 2 per cent to $19.89, and Freightways advanced 1.8 per cent to $6.66.

Outside the benchmark index, Oceanagold Corp rose 5.2 per cent to $4.43. The NZX-listed gold miner has told investors it's engaged in what it terms "constructive" dialogue after the Philippines government named its Didipio site as amongst mining operations that could be suspended because of outstanding social issues.

"There's been a bit of uncertainty and we've seen Oceana be quite volatile - for the week rolling, it's reached a high of $4.93 and a low of $4.06 - but the market's had some confidence about that announcement today," McIntyre said.

Airworks Holdings gained 14 per cent to $5.05. Chinese company Zhejiang Rifa Holding Group (RIFA) has entered a lock-up deed with the major shareholders in the specialist aviation company at $5.40 per share, with a view to making a partial takeover of the company.