New Zealand shares were mixed as trading picked up, with A2 Milk Co and Mercury Energy gaining while Metro Performance Glass fell.

The S&P/NZX50 Index gained 16.46 points, or 0.2 per cent, to 8,324.09. Within the index, 23 stocks fell, 21 rose and six were unchanged. Turnover was $129 million.

"It's slowly picking up - there's a bit more news coming through the market today," said Peter McIntyre, investment adviser at Craigs Investment Partners.

"We've got this familiar trading pattern where it's light trading until midday, and when the Australian market opens up it seems like institutions are getting active in New Zealand. A lot of brokers and fund managers are positioning themselves ahead of earnings seasons."


Pushpay Holdings was the best performer, up 5.5 per cent to $4.06, while Metro Performance Glass dropped furthest, down 2.1 per cent to 92 cents.

A2 Milk Co rose 2.6 per cent to $9.06, having hit a record $9.11 on intraday trading.

"That's on the back of good announcements earlier this year but it's really keeping pace with Bellamy's as well," McIntyre said.

"Bellamy's are up 48 per cent month rolling, week rolling 16.89 per cent, and A2's up 13.88 per cent week rolling. We've seen a lot of significant target price upgrades to Bellamy's and A2's following them. They're both growth-oriented stocks and they tend to deliver."

Mercury New Zealand gained 1.7 per cent to $3.375. It has raised its annual earnings guidance for a second time, as a spell of wet summer weather around Taupo has the power company anticipating increased generation at its North Island hydro stations. Earnings before interest, tax, depreciation, amortisation, and fair value adjustments are expected to be $530m in the year ending June 30, up from a previous forecast of $515m.

Kathmandu Holdings rose 0.8 per cent to $2.41. The outdoor equipment retailer expects a 20 percent lift in first-half net profit on a 4 per cent lift in total sales and wider gross margins. It expects net profit will be at least $12m in the six months to January 31 versus $10m in the first half of the 2017 financial year. Same-store sales grew 1.9 per cent in Australia while in New Zealand they fell 6.4 per cent.

"It seems like they're getting a bit more margin, and have been able to maintain inventory control, but the New Zealand sales declining would have to be a disappointment," McIntyre said.

"The CEO indicated their gross margin has been pretty positive, but it's a bit mixed. It's a stock which gets bounced around a wee bit and some investors are in there seeking a bit of value."


Outside the benchmark index, Michael Hill International gained 5.2 per cent to $1.42. The jewellery chain will wind up its US operations after a decade-long investment failed to build a profitable business, and is overhauling its Emma & Roe jewellery line.

"I think the market is applauding a conviction call to exit - they're going to concentrate on Canada, NZ and Australia," McIntyre said. "Sometimes the market applauds hard decisions, there's no point continuing on a loss-making venture."

ASX-listed Volpara Health Technologies dropped 1.4 per cent to 72 Australian cents. The Kiwi digital health firm reported record quarterly sales in the third quarter and is still on track to exceed its annual recurring revenue growth target for the year.