** Australian copper miners drove mining index .AXMM 1.9% higher to its highest in nearly 21 months
** ASX-listed shares of Capstone Copper CSC.AX jump 10.7% to more than one-year high, while Sandfire Resources SFR.AX surges as much as 12.7% to record high
** Shares of Rio Tinto RIO.AX and BHP BHP.AX, both of which have significant copper portfolios, rose about 4% each
** Copper hit its highest level in more than 15 months on Wednesday after Freeport-McMoran FCX.N declared force majeure at its Grasberg mining complex in Indonesia and slashed production guidance for 2026 MET/L
** CSC, SFR, RIO and BHP among top performers on ASX 200 benchmark .AXJO, which was last up 0.2%
** YTD, the sub-index was up 20.3% vs 7.6% rise in ASX 200
(Reporting by Sneha Kumar in Bengaluru)
((Sneha.kumar@thomsonreuters.com;))