Copper hit a two-week low on Wednesday as a weak yuan and poor Chinese services data fanned fears over slowing growth in a market still reeling from weak China factory activity and a Shanghai equities sell-off earlier this week. China's services sector expanded at its slowest rate in 17 months in December, data showed, while the People's Bank of China set the yuan's official midpoint rate at its weakest level in 4-1/2 years.
Traders and economists fear the yuan's depreciation may mean the economy in the world's top metals consumer is even weaker than had been expected. Benchmark three-month copper on the London Metal Exchange closed down 0.5 percent at $4,620 a tonne, having hit a low of $4,593. Copper lost 25 percent of its value last year.
Copper's falls came despite news that China's state stockpiling agency is expected to start buying as much as 150,000 tonnes of copper. "The fact that this didn't have a positive impact on the market tells you sentiment is very bearish," said Julius Baer analyst Carsten Menke.
"The production cuts (announced last year) do not seem sufficient to tighten the market," he added China's shares ended sharply higher overnight thanks to an extended ban on big share sales, but the gains did not support the wider financial markets. Also offering little support were comments from Chinese President Xi Jinping that Beijing will strengthen supply-side structural reform and will focus on reducing overcapacity.
"It smacks of desperation," said a London-based trader, referring to Xi's comments and the share sales ban. "At the end of the day, this is a new cycle and it's going to take a long time to work through." Surveys earlier this week showed December factory activity in China shrank again, sparking a 7 percent slide in Chinese shares that triggered a trading halt.
In the US private companies added workers at a brisk clip in December, pointing to underlying strength in the economy despite signs that growth slowed sharply in the fourth quarter. Elsewhere, Malaysia imposed a three-month ban on bauxite mining, effective from January 15. A temporary ban could dent stockpiles in China but is unlikely to curb breakneck output in the aluminium sector there, analysts said.
Aluminium closed up 0.8 percent at $1,475, having hit $1,456.50 - its lowest since December 1. Tin ended down 2.5 percent at $13,800, having hit its lowest since late August earlier at $13,650. Indonesia exported 5,804.95 tonnes of refined tin in December, data showed, about double the level exported in November. Zinc closed down 1.7 percent at $1,546, lead ended down 2 percent at $1,679.50, having hit a 2-1/2 week low of $1,678.50, while nickel closed up 0.6 percent at $8,600, having hit its lowest since late November at $8,460.