** Healius HLS.AX slips as much as 17.9% to A$0.665, lowest since December 1998
** Stock marks biggest intraday pct fall since November 2024
** Healthcare co reports FY underlying loss after tax of A$24.8 mln ($15.9 mln) vs year-ago loss of A$15.8 mln
** About 19.7 mln shares traded in stock's busiest session since June 20; 30-day avg is ~3.4 mln
** HLS falls 31.7% YTD
($1 = A$1.5581)
(Reporting by Anjali Singh in Bengaluru)
((anjali.singh2@thomsonreuters.com;))