A REDUCTION in all-in-sustaining costs (AISC) at Newcrest Mining’s Lihir Gold Project during the March quarter helped the company achieve its lowest overall all-time AISC of US$713 per ounce, which was 5.1% lower than the previous quarter. AISC at Lihir in the period was $822, down from $883 in the December 2016 quarter and $950 in the September 2016 quarter.