South32 (ASX:S32) reported a 1% increase in alumina production year-to-date to March, helped by record production in its Brazil Alumina segment, according to a Wednesday filing with the Australian bourse.

Aluminium production was mostly flat during the period, as its Hillside Aluminium smelter continued to evaluate its maximum technical capacity.

Sierra Gorda, a Chile-based copper mine in which South32 holds a 45% stake, delivered a record quarterly distribution of $135 million to the company.

South32 said its annual production guidance remained on track for all operations, apart from Australia Manganese, where the fiscal 2026 production outlook was cut by 6% to 3,000 kilo wet metric tonnes due to elevated site water levels and heavy rainfall following Tropical Cyclone Narelle.