Copper slid to a four-month low overnight after data showed a sharp drop in imports into China, the world's biggest consumer, feeding pessimism over demand following hefty inflows into London Metal Exchange inventories last week.
China's April copper imports fell 30 per cent month on month to 300,000 tons, data from the General Administration of Customs showed, and were down by a third from a year ago as a subdued outlook for industrial activity weighed on demand.
Three-month copper in London closed 1.8 per cent down at $5486 a ton, having earlier touched $5462.50, its lowest since January 4.
Copper inventories in LME warehouses dipped by 3100 tons on Friday, exchange data showed, after surging by more than 100,000 tons in the previous three days.
Money managers raised their net long position in copper futures and options in the week to May 2 Commodity Futures Trading Commission (CFTC) data showed.
LME aluminum ended the day 1.3 per cent down at $US1879 a ton, off an earlier two-month low of $1874.
Stocks of tin in LME warehouses fell by a further 115 tons on Friday to their lowest since 1989 at 2375 tons. LME tin inventories have declined by more than 60 per cent from their mid-February peak.
Zinc closed in a small backwardation on Friday for the first time since February 20.
LME nickel, untraded at the close, ended little changed at $US9145 a ton, while zinc finished 0.3 per cent up at $US2589 and lead 0.6 per cent down at $US2169.