Shanghai copper futures jumped 2 percent at the outset of trade, after LME copper hit a 16-year high of $3,224.50 a tonne in overnight trade. Copper was supported by a weak dollar, fund buying, and strong gains in other metals futures.
But the LME three-month contract dipped in early Asian business as Chinese traders sold. By 0702 GMT, the LME three-month had traded at $3,205.50 a tonne, up 2.3 percent from the same time a day before.
April copper closed in Shanghai at 30,990 yuan ($3,745), up 700 yuan from Thursday's close but short of its 3-percent upper trading limit. Front-month March closed at 31,900 yuan, up 750 yuan from Thursday's close.
But spot prices only rose 300 yuan, to 31,850-32,050 yuan.
The relatively weak spot rise reflected rising inventories in China and abroad, traders said.
Shanghai Futures Exchange data released after the market closed Friday showed copper stocks up 12,088 tonnes in the two weeks ended Thursday, at 34,430 tonnes. Data was not released last week because of the annual Lunar New Year holiday.
A total 161,102 lots of copper futures traded in Shanghai on Friday. Ample aluminium stocks prevented Shanghai aluminium futures from matching a 2.2 percent rise in LME aluminium futures.
The April contract closed at 16,460 yuan, up 0.5 percent from Thursday's close. A total 26,876 lots traded Friday. Shanghai warehouse stocks rose 36 percent to 84,995 tonnes in the two weeks ended Thursday.