New Zealand shares rose as Ryman Healthcare climbed to a new record after last week's strong earnings result, while upcoming index reweightings stoked demand for Fisher & Paykel Healthcare while weighing on Contact Energy.

The S&P/NZX 50 Index increased 45.81 points, or 0.6 per cent, to 8,176.1. Within the index, 20 stocks gained, 23 fell, and seven were unchanged. Turnover was $212 million, with F&P Healthcare accounting for $57.8m and Contact $25.1m ahead of Thursday's MSCI index reweightings which investors anticipate will see the inclusion of the former and the departure of the latter.

Ryman led the market higher, rising 5.6 per cent to a record $10.35. The country's biggest listed retirement village operator has gained 12 per cent since reporting an 8.4 per cent increase in first-half profit and raising its interim dividend last Thursday.

"It's following from its result last week which was pretty good, which just goes to show it's a great business that one," said Craig Stent, head of equities at Harbour Asset Management in Wellington.


"As they get bigger and bigger it's increasingly harder, but with more sites in Australia and larger market, potentially it may be achievable" for Ryman to keep delivering strong earnings growth, he said.

F&P Healthcare rose 2.6 per cent to $13.16, while Contact fell 2.1 per cent to $5.51 as investors prepare for the MSCI index reweightings.

When a stock is included it means certain index-tracking investors, such as passive exchange-traded funds, have to buy the shares, with the reverse also true when a firm leaves it.

Stent said that reweighting heightened turnover in those two stocks today and will likely see increased volatility ahead of the portfolio amendments.

A weaker kiwi dollar continued to boost export-related stocks, including F&P Healthcare and milk marketer a2 Milk Co, which gained 1.7 per cent to $8.47.

Among other stocks to gain, Auckland International Airport rose 2.5 per cent to $6.465, Summerset Gropu advanced 2.4 per cent to $5.12 and Metro Performance Glass increased 2.1 per cent to 96 cents.

Telecommunications network operator Chorus was the worst performer on the day, falling 2.7 per cent to $4. Other stocks to decline included NZX down 2.6 per cent to $1.11, Scales Corp which dropped 2.1 per cent to $3.81 and Air New Zealand, which fell 1.6 per cent to $3.14.

Infratil declined 1.2 per cent, or 4 cents, to $3.26 after shedding rights to an interim dividend of 6 cents per share.

Blue chip stocks Spark New Zealand slipped 0.8 per cent to $3.615, Fletcher Building fell 0.4 per cent to $6.83, Meridian Energy decreased 0.2 per cent to $2.945, Mercury NZ increased 1.3 per cent to $3.41 and Xero slipped 0.2 per cent to $32.75.

Vista Group International rose 1.9 per cent to $2.75 after completing a two-for-one share split in an effort to enhance the cinema software firm's liquidity.

Outside the benchmark index, Green Cross Health rose 1.2 per cent to $1.76 after the medical services provider reported a 16 per cent decline in first-half profit after a year-earlier gain wasn't repeated and a 6.9 per cent gain in sales.

Among companies reporting tomorrow, ERoad rose 0.3 per cent to $3.36, Orion Health Group gained 4 per cent to $1.05, Trilogy International declined 0.8 per cent to $2.58 and Turners Automotive Group increased 0.3 per cent to $3.16.