LME is a physically settled exchange and Marex's Al Munro said regardless of any demand concerns around power distribution curbs on downstream sectors, "in the here and now production declines have a greater effect".

"LME on warrant stocks might have built 7kt this morning but that follows Friday's drop to levels not seen since 1974," he said yesterday.

Cash copper diverged more than $1,000/t from futures, which Bloomberg noted was the biggest premium since 1994, with three-month copper closing down slightly to $10,196/t.

In the US, production at factories fell by the most in seven months in September as an ongoing global shortage of semiconductors depressed motor vehicle output, further evidence that supply constraints were hampering economic growth, Reuters reported.

The gold price has returned to a similar point at this time yesterday, about $1,764 an ounce on the spot market.

Among mining equities, copper producer Freeport-McMoRan closed down 0.25% in New York and gold major Newmont closed down 1.11%.

Finally, Element 29 Resources (TSXV: ECU) rose more than 12% in Toronto to a new closing high of C65c, after reporting 383.75m at 0.71% copper-equivalent in one of the two first drill holes at its Elida copper project in Peru.