** Shares of Australia's Reliance Worldwide Corp RWC.AX fall as much as 8.9% to A$4.19, their biggest intraday pct since August 21, 2023

** Stock hits lowest level since biggest intraday pct loss since August 5

** The plumbing and heating products manufacturer says imposition of additional U.S. tariffs expected to adversely impact operating earnings and margins

** Co sees net cost impact of tariffs on FY26 operating earnings (EBITDA) to be in the range of A$25 mln ($16.23 mln) to A$30 mln

** Expects H1 FY26 consol group EBITDA margin to be lower than last year due to lower volumes and tariff impacts

** YTD, stock down 13.8%

($1 = 1.5404 Australian dollars)

(Reporting by Shruti Agarwal in Bengaluru)

((Shruti.Agarwal@thomsonreuters.com))