** Shares of Australia's Power Minerals PNN.AX rise as much as 8.4% to A$0.090, their highest point since September 2
** The critical minerals explorer Power Minerals says re-assays of 21 samples from its Santa Anna niobium-REE project in Brazil returned the highest rare-earth grades recorded at the site to date
** Around 4.5 million shares change hands, nearly 2.9x 30-day average
** PNN stock down 7.6%, YTD
(Reporting by Keshav Singh Chundawat in Bengaluru)
((Keshav.SinghChundawat@thomsonreuters.com))