Aluminium prices retreated on Friday as falling alumina prices and a weak demand outlook dragged the metal used in transport and packaging to its lowest level since January 2017.
Benchmark aluminium traded 0.2% lower at $US1,733 a tonne in official rings after touching $US1,723.50. It was 3.4% down over the week.
Weaker demand because of slowing industrial activity could push prices slightly lower, said Bank of China International analyst Xiao Fu.
She said winter production curbs in China, the largest producer, are likely to be more moderate than last year and provide less support for prices.
Profits at China's industrial companies contracted in August, reversing the previous month's brief gain, as weak domestic demand and trade tensions weighed on corporate balance sheets.
The data followed a Reuters poll showing that China's factory activity is likely to contract for a fifth straight month in September.
Trade talks between the United States and China are set to resume in Washington DC on October 10, CNBC reported on Thursday. The trade dispute has dragged on for 15 months and damaged economic growth and metals prices.
World equities markets dipped and the US dollar was near its strongest since 2017, pressuring metals by making them more expensive for buyers with other currencies.
Prices of the main raw material for aluminium have more than halved from last year's peaks and - at $US294 a tonne - are at their lowest since June 2017, dragging down aluminium prices.
Premiums for aluminium shipments to Japan for October to December were set at $US97 a tonne, down 10% from the previous quarter, amid ample supplies in Asia and softening demand, sources told Reuters.