New Zealand shares fell on the first day of the month in a muted trading session after institutional investors staked out positions yesterday. Contact Energy and Summerset Group Holdings declined.

The S&P/NZX50 Index dropped 58.14 points, or 0.7 per cent, to 8,383.87. Within the index, 34 stocks fell, eight rose, and eight were unchanged. Turnover was $96 million.

The benchmark index gave up some of yesterday's gains when it jumped 1.7 per cent on turnover of more than $200m. That month-end positioning by large investors coincided with Xero's final day of trading on NZX to become solely listed on the Australian Securities Exchange.

"It was the end of the month as well, and that's often when you get the big portfolio trades which influence outcomes over a day, settling positions for the end of a period or whatever," said Greg Easton, investment adviser at Craigs Investment Partners.


"Today's so quiet, and that probably does reflect that a lot of that positioning was completed yesterday."

The worst performer was Contact Energy, down 2.3 per cent to $5.46, with Summerset falling 2.1 per cent to $5.63.

"A lot of the gains yesterday happened towards the end of the day's trade, which really does indicate it was that funds management end of the market dictating things," Easton said.

The stocks that gained the most yesterday faced the biggest losses today, with SkyCity Entertainment Group down 1.9 per cent to $4.07, paring some of Wednesday's 4.3 per cent gain. Air New Zealand dropped 1 per cent to $3.05 having gained 3.7 per cent yesterday, and Sky Network Television dropped 1 per cent to $2.88 after it advanced 3.6 per cent previously.

The best performer today was Fonterra Shareholders' Fund, which rose 1.5 per cent to $2.69, while Mainfreight gained 1 per cent to $26.01.

Outside the benchmark index, Pacific Edge shares rose 12 per cent to 43 cents after the cancer diagnostics firm signed its first commercial deal to supply its suite of Cxbladder tests in Singapore.

The Dunedin-based company said it reached a commercial agreement with a unit of Raffles Medical Group to use the bladder cancer tests in Singapore. Under the deal, the Raffles unit will coordinate specimen collection, shipping and reporting of Cxbladder tests for the medical firm's patients in the Asian city.

"They've signed heaps of these sorts of agreements in the States where we've been looking to see the revenue flow from, but it really hasn't started so while this is possibly good news it is going to be a long time before revenues really flow," Easton said.


"It's good that they're out there selling it anyway, and the product obviously has a market."