In a context of massive sales, copper in Shanghai backed down on Friday. Chinese investors exited the market during the last trading session before the long Lunar New Year vacation.

The most active copper contract on the stock exchange Shanghai futures fell by 1.97% to 100,660 yuan (14,576.79) dollars) per metric ton at 02:45 GMT, but should end the week in increase of 0.65%.

The three-month copper reference price on However, London Metal Exchange grew by 0.63% to reach 12,957 dollars per ton, remaining below the mark of $13,000, and should end the week down 0.32%.

The London benchmark fell by 2.21% Thursday.

Physical demand is falling in China before the break of nine days starting on 15 February.

The cash copper premium, paid in addition to SHFE copper price, changed on Thursday into a discount of 60 yuan per ton, a sign of a weakening in demand.

The Yangshan copper premium, indicator of the appetite of the Chinese for imported materials fell to 34 dollars a ton.

Elsewhere, tin and nickel blamed the most sharp declines. The most active tin price in Shanghai fell by 3.89%, and the reference one in London lost 2.74%.

Shanghai nickel fell by 3.68%, while London nickel fell by 0.91%.

Nickel losses are due to sales of benefits following Indonesia's latest decision to reduce quotas of exploitation of the largest nickel mine in the world.

Among other SHFE base metals, aluminum has fell by 1.31%, zinc fell by 0.79% and lead fell by 0.42%.

Elsewhere on the LME, aluminum fell slightly by 0.11%, zinc fell by 0.06% and lead fell by 0.10%.