A2 and Kathmandu lead sharemarket higher

Kathmandu Holdings' stock has gained 10.3 per cent this month.

New Zealand shares rose, led by A2 Milk's continued strength, along with Kathmandu Holdings on a two-and-a-half year high and Air New Zealand rising.

The S&P/NZX50 Index gained 44.62 points, or 0.6 per cent, to 7628.57. Within the index, 30 stocks rose, 12 fell and eight were unchanged. Turnover was $124.5 million.

A2 Milk led the index, up 5 per cent to $4.02. The stock has gained 80 per cent this year.

"It's having a nice run, there have been some broker upgrades with regards to that stock, and there's pretty reasonable volume compared to the rest of the market," said Peter McIntyre, investment adviser at Craigs Investment Partners.

Kathmandu Holdings gained 4.7 per cent to $2.25, a price last seen in December 2014. The stock has gained 10.3 per cent this month, soaring since July 3.

"Not huge volumes, there's no news flowing from that company at all," McIntyre said.

"There's been a wide range of prices traded through today, sometimes it's a stock that doesn't carry a great deal of liquidity so if investors are wanting to buy that share price can move. On the other hand retail numbers out of New Zealand and Australia have been strong, we've had a bit of a cold snap as well which may be good for their clothing range."

Vista Group International advanced 3.5 per cent to $5.95. The shares climbed after 20th Century Fox Film became the newest studio customer for its Movio unit in what the Kiwi firm sees as proving the value of the analytics business.

"The market has really liked that, it's another good bit of news which has come from that company," McIntyre said.

Air New Zealand rose 2.4 per cent to $3.57 and has gained 59 per cent this year.

"It's continued to have a good run, oil prices have moved to the downside because of oversupply in the market and I think that has given investors confidence they'll stay lower for longer," McIntyre said.

Trade Me edged up 0.2 per cent to $5.35. The country's dominant online auction site will buy Limelight Software, which operates the cloud-based auto dealer management platform motorcentral.co.nz, for an undisclosed sum provided it gets Commerce Commission approval.

CBL Corp was the worst performer, down 1.2 per cent to $3.30.

Outside the benchmark, SLI Systems shares sank 8 per cent to 23c, a record low.