** Australian Rare Earths AR3.AX surges as much as 60%
** Stock posts biggest intra-day pct gain since April 2023,
hits highest since mid-Jan
** Mineral explorer increases its rare-earth oxide estimates
by 27% at Koppamurra rare earths project in South Australia
** About 1.3 mln shares traded, busiest day since mid-Aug
** Stock last up a little over 38% on the day
** That takes gains in Sept to 88.5% and cuts YTD losses to
about 13%
(Reporting by Kumar Tanishk in Bengaluru)
((Tanishk.Kumar@thomsonreuters.com;))