The copper survey found prices were expected to fall below $US7000 ($A7449) a tonne this year for the first time since 2009.
 
A test of the $6000/t level was deemed likely over the second half.
 
Reuters said concerns over global economic growth, particularly in China, had combined with a sharp acceleration in supply to push copper prices to a four-year low in March.
 
“While many commodities markets have been on the back foot of late, the copper market has been particularly susceptible to weakness given its heightened exposure to the Chinese market, through both traditional end-use demand as well as finance-related routes,” Reuters senior base metals analyst Rob Smith said.
 
“With the risks to the copper market skewed to the downside against a backdrop of rising mine supply and modest market surpluses, prices are likely to remain subdued over the rest of this year.”
 
Reuters said global mine production grew around 8% last year to 17.8 million tonnes, with Chile and the Democratic Republic of Congo making big contributions.
 
Higher productivity and the commissioning of new projects and expansions also saw production rise across all copper regions.
 
“Looking ahead, mine output is set for a period of above trend growth that will lead the copper market into surplus over the medium term, although it should be acknowledged that rising capital costs, easing prices and a shift in mindset amongst mining companies towards one of constraint could lay the foundations for renewed tightness later in the decade,” Reuters said.
 
While mine supply last year was robust, growth in refined output was lacklustre, rising 3% to 20.7Mt.
 
Reuters said technical issues smelting material from new mines, logistical issues and stockpiling concentrates in remote locations all contributed to the comparatively modest growth.
 
Maintenance shutdowns at key smelters and limited scrap availability were also key contributors.
 
At the other end of the spectrum global copper consumption rose 4% last year driven by strong growth in China.
 
It was the fastest pace of expansion since 2010.
 
Reuters said all end-use sectors recorded gains, with electrical products rising 6%, driven by expansion in the Chinese power utilities sector.
 
Looking forward Reuters said increased supply was not the only downside for copper, with rising concerns over its use as a financing tool.
 
Copper is used as collateral by companies and investors in China and Reuters said such activities added further weight to the red metal’s downside bias.