Shanghai Futures Exchange copper fell 2.5 percent to 51,740 yuan ($8,023) a tonne on Friday. Other Shanghai metals also soured, with nickel down 3 pct, aluminium losing 2.8 percent and zinc falling 2 percent after slow and steady Chinese and global manufacturing growth fuelled the metal's longest winning run since 2006. Traders said copper broke the key support which triggered profit-taking after a 20 percent advance since June.
"Copper broke key support levels. But (buying) support should be here for copper," said one trader in Asia. China posted stronger-than-expected import growth in August, reinforcing views that the world's second-largest economy is still expanding at a healthy pace despite tighter policy.
China's imports of copper and copper products held steady for a fourth month, indicating demand remains robust in the world's largest consumer of the metal despite surging prices. "Copper imports were flattish as expected for August. In the months ahead there might be a lift in metal imports... if there is a restriction on smelter production due to environmental inspections," said analyst Daniel Morgan of UBS in Sydney. "That would be bullish for copper."