Oct 19 (Reuters) - Sandfire Resources Nl SFR.AX
* FY2018 production guidance maintained at 63-66kt cu and 35-38koz gold at c1 us$1.00-1.05/lb
* copper production for Sept quarter was 15,258 tonnes versus 17,092 tonnes in June quarter
* targeted copper production for FY2018 remains unchanged
* Sees FY18 headline c1 cash operating costs are expected to be within range of US$1.00-1.05/lb