Rio cuts NZ aluminium smelter output about 30 pct

SYDNEY, Nov 10 (Reuters) - Aluminium production at Rio Tinto Ltd/Plc's Tiwai Point smelter in New Zealand has been cut by the equivalent of about 280 tonnes per day due to equipment failure, a company spokeswoman said on Monday. The smelter has capacity to produce up to 350,000 tonnes of aluminium annually but was already operating at a reduced rate of 315,000 tonnes prior to the failure of an electrical transformer late Sunday, the spokeswoman said. "We have shut one of the potlines and are currently assessing the degree of damage to the transformer," she said, adding it was too early to determine the duration of the curtailment. Lost production was estimated at around 8,500 tonnes on a monthly basis while the potline was inoperable, according to the spokeswoman. The smelter has been running below capacity since May to help reduce demand on New Zealand's national electricity grid.