** Shares of Australia's Orica Ltd ORI.AX fall as much as 1.7% to A$20.3, their lowest level since April 7
** Stock set for a fourth consecutive session of losses, if current trend holds
** Explosive maker flags impact of outage at a third-party supplier's ammonia plant in Australia
** Says securing alternative ammonia and ammonium nitrate supply from current inventory and its global manufacturing and supply network
** Says mitigating impacts on its customers until the ammonia plant resumes operations, estimates mid-May 2026 resumption
** YTD, stock down 15.9%
(Reporting by Aamir Sheik Khalid in Bengaluru)
((Aamir.SheikKhalid@thomsonreuters.com))