** Air New Zealand AIR.NZ falls 3.6% to NZ$0.598; set for biggest intraday pct drop since February 24
** Stock worst performer on benchmark NZ50 index .NZ50, which is trading flat
** CEO Greg Foran will step down in October after five years at the helm
** Co has yet to name successor
** Says global search for new CEO underway
** AIR down 0.4% YTD
(Reporting by Himanshi Akhand in Bengaluru)
((Himanshi.Akhand@thomsonreuters.com;))