** Shares of Great Northern Minerals Limited GNM.AX rise as much as 250% to A$0.063, posting its biggest intra-day pct gain ever

** Stock hits its highest level since December 16, 2022

** Mineral explorer signs binding agreement to acquire Catalyst Ridge rare earths-antimony project in California, USA, from private entities

** Co to also raise A$2.6 million ($1.67 million) via a placement to fast-track Catalyst Ridge exploration, others

** Around 46.9 mln shares traded in stock's busiest day ever, 207.8x the 30-day avg

* Stock last up 216.7%, bringing YTD gains to 307.1%

($1 = 1.5567 Australian dollars)

(Reporting by Ananya Verma in Bengaluru)

((ananya.verma@thomsonreuters.com;))