The vast earthquake in Chile sent copper prices jumping to a three-week peak on Wednesday, as traders worried about possible supply problems in the top global producer.

At 1230 GMT, copper rallied to $6,734 per tonne, striking the highest point since March 10.

"Copper has hit a three-week high as an enormous earthquake off the coast of Chile as sparked fears of a tsunami," said IG analyst David Madden.

"Traders are concerned that copper supplies will suffer following the natural disaster."

Chile is the biggest copper producer in the world and accounts for almost one-third of global supplies.

Analysts noted however that no earthquake damage to copper facilities had been reported.

"The copper price climbed temporarily to a three-week high of over $6,700 per tonne after a severe earthquake occurred off the coast of Chile overnight, giving rise to concerns about supply outages," noted Commerzbank analyst Carsten Fritsch.

"So far, however, there have been no reports of any damage, and some mining companies have already sounded the all-clear."

Copper has experienced volatile trading so far this year, diving last month on demand worries in top global consumer China.

The market had plunged in March to the lowest level for three and a half years on fears about the impact of that China's economic slowdown.

The base metal had dived on March 19 to $6,321 per tonne, which was the lowest point since July 2010.

Meanwhile on Wednesday, the London-based International Copper Study Group (ICSG) forecast that global copper supply would exceed demand in both 2014 and 2015, after three years of deficits.

"World production of refined copper is expected to exceed demand for refined copper by about 400,000 tonnes, as demand will lag behind the growth in production," the ICSG forum said in a report issued after its spring meeting in Lisbon.

"For 2015, although growth in usage is anticipated to continue, another surplus could occur owing to an increase in refined output that exceeds the expected growth in usage."