** Shares of Cettire CTT.AX tumble 16% to A$1.22

** Stock hits its lowest level since Dec. 18

** Retailer says about 7.5% of US gross sales were related to items manufactured in jurisdictions impacted by new US tariffs

** Co says continuing to assess changes to tariffs on imports

** 5.3 mln shares change hands, 2.3 times the 30-day average of 2.3 mln shares

** Stock has fallen nearly 20% YTD, including current session moves

(Reporting by Manasi Dasa Sundeep in Bengaluru)

((Manasi.DasaSundeep@thomsonreuters.com;))