** Shares of Australia's Athena Resources AHN.AX rise as much as 33.3% to A$0.004, their biggest intraday pct gain since September 22, 2025
** Stock at its highest level since March 13
** Mineral explorer announces joint venture agreement with Fenix Resources FEX.AX, Terra Mining
** Joint venture to explore, develop and produce premium magnetite concentrate at Narryer Prospect
** JV targets Q1 2028 start-up, subject to studies and approvals
** Nearly 3.6 million shares change hands, 2.1x the 30-day average volume
** AHN stock has fallen 38.5% this year, including session moves
(Reporting by Roshan Thomas in Bengaluru)
((Roshan.Thomas@thomsonreuters.com))