New Zealand shares dipped from a record high, with Air New Zealand and Mercury New Zealand falling while Synlait Milk and Fletcher Building gained.

The S&P/NZX50 Index fell 4.45 points, or 0.05 per cent, to 8,708.78. Within the index, 21 stocks fell, 20 rose and nine were unchanged. Turnover was $206 million.

The driving force behind many movements on the exchange today was a review of global stock indices by MSCI. A2 Milk Co started the day higher after MSCI included it in its main global index, but closed down 1.5 per cent to $13.10.

Mercury New Zealand dropped 1.4 per cent to $3.11 on news it will leave the main MSCI index. Separately, Infratil, the investment company that owns 50.8 per cent of Tilt Renewables, says it wouldn't approve Mercury increasing its new 19.99 per cent holding in Tilt, having made its own offer for the stock.


Yesterday Mercury said it agreed to buy the stake in Tilt, the wind and solar generation company split from Infratil-controlled Trustpower in 2016, from the Tauranga Electricity Consumer Trust (Tect) for $144m, a 24 per cent premium.

Mercury said it had a six-month option to buy the trust's remaining 6.8 per cent holding in Tilt at the same price, but under New Zealand's Takeovers Code any move above 20 per cent would likely require it to make an offer for the whole company.

"It looks interesting for Mercury from here, obviously Infratil are very happy with their ownership in Tilt and don't necessarily want other holders to go beyond that threshold," said Peter McIntyre, investment adviser at Craigs Investment Partners.

"There was an expectation they were going to play a long game on this, but it may fizzle out at the 19.9 per cent holding.

"There are question marks about their balance sheet capacity, I think some analysts are pondering the buy-in - whether it's a well thought-out process or whether it's an acquisition for acquisition's sake," McIntyre said.

"Some parts of the market are second-guessing what they're doing. They obviously see this as a way to grow revenue for the longer term, but there are question marks, particularly if they're not going to go further than 20 per cent. "

Air New Zealand led the index lower today, down 2.2 per cent to $3.31, while Chorus dropped 2.2 per cent to $4.015 and Fisher & Paykel Healthcare Corp fell 1.8 per cent to $12.88.

Fletcher Building, which was tipped to possibly exit the main MSCI index, will remain, and gained 3 per cent to $6.56.

"Some people had expected it to go out, but we've also had Fisher Funds make an announcement today that they're buying in, which has given the stock an upward tick today," McIntyre said. "A number had probably shorted the stock and they're buying back in today."

Synlait Milk, which will enter the MSCI small-cap index at the end of the month, was the best performer today, up 5.5 per cent to $10.75.

"If we go back to April, when Synlait announced they were going to double their lactoferrin capacity, they've been on an upwards price trajectory since then," McIntyre said. "Synlait has got a good story, they're spending capital on growing their business and they've captured investors' imaginations."

Other stocks to join the small-cap index also gained, with Tourism Holdings up 3.8 per cent to $6.35 and Restaurant Brands rising 1.1 per cent to $7.70.

NZX was unchanged at $1.10. It plans to raise as much as $40m via the sale of subordinated notes that mature in June 2033 to repay existing bank debt and for general corporate purposes.