The price of aluminium jumped to its highest in more than three months on Wednesday after Norsk Hydro said it would halt output at its Alunorte alumina refinery, stoking concerns about shortages of the raw material. Three-month aluminium on the London Metal Exchange touched its highest since June 15 at $2,238 per tonne and ended 4.2 percent higher at $2,206 a tonne.
The alumina market is in tight supply this year due to the outage at Norsk Hydro's plant in Brazil, US sanctions on Russian producer Rusal and a strike at Alcoa's alumina refineries in Australia that was resolved last week.
"The aluminium market was caught on the wrong foot given that we had the relaxation of the supply issues in Australia last week which kept prices under pressure," said Carsten Menke, analyst at Julius Baer, adding supply risk from Russia's Rusal had been priced out of the market. The market is concerned about aluminium stocks on the LME market, which at 979,800 tonnes have more than halved since January last year and are at their lowest since early 2008.
Unionised workers at aluminium producer Alcoa's Western Australian operations agreed on Friday to end a strike that lasted more than six weeks after securing better job security provisions in a new wage agreement.
Norsk Hydro's Alunorte alumina refinery has been operating at half capacity since March due to an environmental dispute. Wednesday's announcement of production stoppage sent the company's shares down 11 percent.
Researchers at Citi reiterated their "Buy" recommendation on aluminium as they remain confident that aluminium demand growth would outpace supply in China between 2018 and 2020.
China said last week it would allow local authorities to adopt output curbs based on regional emission levels as part of its anti-pollution plan for winter.
Total inventories of copper in LME warehouses fell to 194,175 tonnes, the lowest since December.
The copper market should see a deficit of 92,000 tonnes this year and a deficit of 65,000 tonnes in 2019, the International Copper Study Group said. Meanwhile, copper output from Africa's top producer, the Democratic Republic of Congo, is expected to rise 11.6 percent to 1.2 million tonnes by the end of 2018.
Copper ended 0.2 percent lower at $6,267 a tonne, zinc eased 0.6 percent to $2,650, after hitting its highest since July 9 on Tuesday at $2,728, lead was down 2 percent at $2,020, tin inched up 0.2 percent to $18,990, while nickel rose 2 percent to $12,770.