New Zealand's a2 Milk slips on ex-dividend trade
** Shares of a2 Milk ATM.NZ fall as much as 2.8% to NZ$8.32, their largest intraday pct drop since September 1
** Dairy producer trades ex-dividend
** Co declared total dividend of 21 New Zealand cents per share
** Stock down 18.4% YTD, including the day's moves