New Zealand shares have risen, pushing the NZX 50 Index to a new record, as investors were attracted by the prospect of continued earnings and dividend growth.

Tech companies Diligent Board Member Services and Xero continued their ascent.

The NZX 50 rose 12.548 points, or 0.3 per cent, to 4366.575. Within the index, 22 stocks rose, 21 fell and seven were unchanged. Turnover was $156 million.

Diligent, which provides web-based portals for boards of directors, climbed 3.4 per cent to a record $6.46. The company told the NZX on Monday it can't explain the meteoric rise, on increased volumes of stock traded.

"It is an incredibly well-performing company with high growth rates that are sustainable," said Mark Warminger, a portfolio manager at Milford Asset Management. "As the story is more and more discovered you're getting more people buying into the story," he said. The stock is "moving up to fair value".

Xero, the cloud-based accounting company which is yet to turn a profit, rose 4.4 per cent to $9.50, a record close.

Telecom, the biggest phone company on the NZX 50, rose 2.8 per cent to $2.41 and Ryman Healthcare climbed 1.5 per cent to $4.63.

More than half the stocks on the benchmark index have gained more than 20 per cent in the past 12 months and eight are up more than 50 per cent. The latest earnings season gave investors room for optimism.

"In terms of valuation the local share markets currently appear slightly above fair value on a Price/Earnings basis," Warminger said.

"We expect earnings to be revised upwards over the coming 12 months, and this would mean that markets could hold further upside."

Government figures on Monday showed retail spending on credit, debit and charge cards rose 0.8 per cent, seasonally adjusted, last month, according to Statistics New Zealand.

That's the biggest gain since August last year and beats the median forecast in a Reuters survey of 0.5 per cent.