New Zealand shares fell, led by A2 Milk after the milk marketing company's chief executive unexpectedly left the company, effective immediately.

The S&P/NZX 50 Index dropped 46.61 points, or 0.4 per cent, to 11,229.59. Within the index, 29 stocks fell, 17 rose, and four were unchanged. Turnover was $164.5 million.

A2 Milk fell as much as 7.7 per cent, ending the day down 3.6 per cent at $14.62 on a volume of 3.5 million shares. Chief executive Jayne Hrdlicka announced her exit from the firm after almost a year and a half, citing too much travel for her to manage her other commitments. Previous head Geoffrey Babidge, who oversaw the company's transformation from a penny-dreadful to at times the country's biggest listed company, was appointed acting chief executive while a replacement is sought.

"That was very much out of left-field – we saw the stock trade down as low as $14," said Matt Goodson, managing director at Salt Funds Management. "They reiterated guidance and most importantly, talked about a 30 percent margin out in the medium term."


Chorus fell 2.1 per cent to $5.92. The telecommunications network operator has been repairing damaged lines from the South Island flooding, which saw more than 3,000 customers lose broadband and phone services over the weekend.

Spark New Zealand, which also experienced outages over the weekend, was down 0.7 per cent at $4.40 on a volume of 3.8 million shares, the most active stock for the day.

Fonterra Shareholders' Fund units declined 0.7 per cent to $4.07. Fonterra Cooperative Group said milk collection had been affected by the flooding. Synlait Milk, which has a processor in Canterbury, fell 1.4 per cent to $9.15.

South Island hydro scheme operators were mixed. Meridian Energy increased 0.2 per cent to $5.01 on a volume of 1.8 million shares. Contact Energy fell 0.4 per cent to $7.20 with 1.2 million shares traded.

NZX posted the day's biggest gain, up 4.1 per cent at $1.28 on a volume of 560,000 shares. The stock market operator today said annual operating earnings will be at the top of guidance, reflecting increased capital raisings, one-off revenue from its data and insights business, and consulting revenue from energy contracts.

Goodson said the upgrade appeared to be driven by one-off items.

Genesis Energy rose 2.8 per cent to $3.115, Ryman Healthcare was up 2 per cent at $15.67 and Pushpay Holdings advanced 1.8 per cent to $4.02.

Freightways increased 0.5 per cent to $8.24. The courier and information management firm is often seen as a bellwether for the economy, and manufacturing figures out today were seen by ASB Bank economists as supporting faster growth in the September quarter than previously predicted.


Of other stocks trading on volumes of more than a million shares, Kiwi Property Group fell 1 per cent to $1.53, Goodman Property Trust was down 0.5 per cent at $2.18, and Arvida Group was unchanged at $1.60.

Outside the benchmark index, Evolve Education was unchanged at 14.5 cents. The early childhood education provider bought five centres in Canberra for A$12m ($12.5m).

Millennium & Copthorne Hotels NZ rose 2.4 per cent to $2.56. The hotel operator today played down reports that it was negotiating with the Catholic Diocese of Christchurch over the church's plans for a new cathedral. It said no direct negotiations had taken place, and that while it had received multiple proposals for its land, but none had led to an agreement.

Smartpay fell 4.5 per cent to 53.5 cents. The payment systems operator has almost doubled in value since announcing the $70m sale of its New Zealand assets to US firm Verifone late last month.