London Metal Exchange (LME) copper dropped to a 10-week low on Monday as technical selling replaced earlier trade sales and weighed down most of the market, traders said.
"What really unsettled the market is that once selling started there was no buying interest," one dealer said.
"Against a background of Chinese selling, where it seems the country is cutting back on its raw materials demand, the spreads, particularly in copper, were well offered, undermining the market.
"Other markets followed copper, with the exception of tin, which has tighter spreads."
Traders said an easing in nearby spreads for cash-threes copper to $60 by the kerb close from almost $100 backwardation in the morning had weighted bearish sentiment.
Copper ended the rings at $2,512 a tonne from $2,592 at Friday's kerb close.
Traders put copper's next support at $2,500 and, failing that, at $2,450.
Other base metals followed copper down, with the exception of tin, which had been ring-fenced against losses due to its tight fundamentals.
Backwardations for tin continued to widen, with no respite seen as warehouse inventories fell further, despite a soaring cash price which would normally attract metal to the exchange, traders said.
The cash/threes backwardation flared out to $800/900 from around $650 on Friday and some $375 a week ago. Physical market premiums have held at levels of some $250, despite the high backwardations of the last month.
Cash/one day, which today is for the May 'third Wednesday', was indicated at $20 backwardation, while June/three months traded at $500 backwardation.
Tin was at $8,700 at the kerb close from $8,760.
Aluminium was at $1,583 from $1,615, while zinc was at $1,016, down $2. Nickel was at $10,550 from $10,825, while lead was at $730 from 734.