New Zealand shares edged lower as electricity companies remained under pressure as the future of the Tiwai Point smelter remains uncertain and after a weak operating update from Contact Energy.

The S&P/NZX 50 Index decreased 4.55 points, or 0.04 per cent, to 10,894.70. Within the index, 21 stocks fell, 23 rose, and six were unchanged. Turnover was $131.4 million.

Blue-chip stocks and companies held for the reliable dividends were among those to decline, despite a recent slide in bond yields that would typically make equity markets more attractive.

Power companies were among the day's decliners as investors continued to ponder whether Rio Tinto will pull the pin on the smelter, and what the latest operating updates meant. Mercury NZ fell 2.3 per cent to $4.91 with 862,000 shares changing hands, less than its 90-day average of 1.1 million, having recently been added to the MSCI Index. Genesis Energy was down 1.9 per cent at $3.17.


Meridian Energy, the country's biggest listed company, declined 1.5 per cent to $4.53 with 2.1 million shares changing hands, and Contact Energy decreased 0.4 per cent to $6.90 on a volume of 1.3 million.

"Mercury came off despite it going into the upcoming MSCI index, although volumes are very light, and Contact did have quite a weak monthly update the other day," said Matt Goodson, managing director at Salt Funds Management.

Goodson noted that Contact was also exposed to a potential exit by the Tiwai Point smelter, and that some investors had thought it would get added to the MSCI index.

Property stocks were mixed as investors digested the recent capital raising by Kiwi Property Group, which is also scheduled to report earnings on Monday. Kiwi Property rose 1.9 per cent to $1.58 on a volume of 3.4 million shares - about twice its average turnover. It was the most actively traded stock today.

Precinct Properties New Zealand fell 0.6 per cent to $1.78, Investore Property was down 0.5 per cent at $1.85 and Argosy Property decreased 0.3 per cent to $1.40. Goodman Property Trust was unchanged at $2.075.

Vista Group International led the market lower, down 3.2 per cent at $3.90 on a volume of 150,000 shares, less than half its 469,000 average.

Scales Corp posted the day's biggest gain, up 5.2 per cent at $5.24 on a volume of 49,000 shares, about half its 97,000 average.

Fonterra Shareholders' Fund units increased 0.5 per cent to $4. Fonterra Cooperative Group today said its managing director of people and culture, Deborah Capill, will leave the company next year.


Of other stocks trading on volumes of more than a million shares, Fletcher Building was up 1 per cent at $5.30, Infratil rose 1 per cent to $4.85, Spark New Zealand increased 0.7 per cent to $4.45, and Auckland International Airport was up 0.2 per cent at $14.34.

Outside the benchmark index, IkeGPS jumped 9.6 per cent to 91 cents. It appointed former Chorus executive Mark Ratcliffe to its board today.