Australian miners hit a three-month low on softer copper prices
** Australian miners .AXMM fall as much as 1.3% to their lowest level since July 21
** Copper prices dropped overnight as inventories rose, easing worries over supply MET/L
** Rio Tinto RIO.AX and BHP BHP.AX drop 1.4% and 1.2%, respectively
** Fortescue FMG.AX slips 3.2% after saying its operations may be affected if negotiations with CMRG over supply contracts and price negotiations are not concluded by calendar year-end
** Sub-index up 4.4% YTD