Losses bucked a generally positive tone in other risk-asset markets like equities and crude oil, as well as stronger move in the euro versus the dollar, as copper investors returned their focus to a dimmer demand and brushed aside renewed supply-side troubles at a major copper mine in Indonesia.
"The macro demand picture is trumping all today," said Michael Gross, futures analyst with Optionsellers.com in Tampa, Florida.
London Metal Exchange (LME) three-month copper shed $45 to end at $8,390 a tonne.
In New York, the March COMEX contract fell by 2.75 cents to settle at $3.8060 per lb, after dealing between $3.7735 and $3.8395.
Copper slumped after European Commission interim data showed euro area GDP was expected to shrink 0.3 percent this year compared with a previous forecast for 0.5 percent growth, with the region likely to head into its second recession in just three years.
"The outlook for the euro zone economy is weighing on sentiment," said Peter Fertig, a consultant at Quantitative Commodity Research.
"If the euro zone is in a recession and is importing less, this has implications on Chinese exports and Chinese growth, which will impact base metals."
Those growth implications in China, which consumes 40 percent of the world's copper, were realized in a preliminary purchasing managers' survey in China on Wednesday, showing export orders falling the most in eight months.
Copper failed to garner much support from news of renewed violence and work stoppage at Freeport-McMoRan Copper & Gold Inc's vast Grasberg mine in Indonesia due to an unresolved issue with the company.
"The longer the issue goes on, the bigger factor it will become," Optionsellers.com's Gross said.
"The market is still digesting the European news, focusing on the macro. The strike will be something to keep an eye on in the coming days and weeks."
STRONG POTENTIAL FOR ALUMINIUM
Expectations of a global copper production deficit are supporting prices, but it is unclear when demand will rise, said Germany's Aurubis, Europe's biggest copper producer.
Compared with copper, there may be more upside potential for aluminium which has gained more than $100 in less than a week. It was untraded at the close but bid at $2,273, from a close of $2,280, not far from its 200-day moving average at $2,311.66.
"If it broke through its 200-moving day average, it would potentially be quite a strong signal," said ANZ senior analyst Nick Trevethan.
"Near-term prospects look quite decent for aluminium. There's reasonable demand from the aerospace sector, and from the auto sector in North America at least and higher energy prices are also supporting the market."
Aluminium stockpiles at LME warehouses staying at record highs above 5 million tonnes as well as excess smelting capacity had pressured prices late in 2011 even as bulk of the LME stocks are believed to be tied to financing deals.
Zinc ended down $19 at $2,048 a tonne, a day after Teck Resources Ltd and Korea Zinc came to terms on annual zinc processing fees of $191 per tonne.
This fee stands well above spot treatment and refining charges (TC/RCs) in China, which may rise above $100 this year as loss-making smelters cut output, a senior analyst at state-backed firm Antaike said.