Top Chinese party leaders on Friday said they would push forward structural de-leveraging and prevent speculation in the property market, suggesting attention may be turning back to debt risks that any further major stimulus measures may create.
The news sent Chinese stocks down on Tuesday, extending a sharp decline in the previous session.
"People are worried that the accommodative policy may face an end," said Shanghai-based copper analyst He Tianyu of metals consultants CRU.
Three-month copper on the London Metal Exchange fell 0.8 percent to $6,427.50 a tonne by 0707 GMT, while the most active copper contract on the Shanghai Futures Exchange ended down 0.5 percent to 49,160 yuan ($7,323.76) a tonne.
Benchmark nickel dropped as much as 0.9 percent to $12,560 a tonne, its lowest intra-day level since Feb. 19, while Shanghai's most active nickel contract closed 1.2 percent lower to 98,440 yuan a tonne.
FUNDAMENTALS
* NICKEL DEFICIT: The global nickel market deficit narrowed to 2,000 tonnes in February from a revised deficit of 3,700 tonnes in January, and was much smaller than a 7,200-tonne deficit in the same month last year, the International Nickel Study Group said on Monday.
* ALUMINIUM: China's environment ministry reprimanded provincial officials in Shandong, the country's biggest aluminium producing province, for failing to curb the growth of highly-polluting aluminium output.
* CHINA SCRAP: China's scrap copper imports in March fell 54 percent from a year ago to 100,000 tonnes, the second-lowest monthly figure in records since June 2014.
"I believe it is because of (China's) tighter regulation on scrap imports coupled with overall less demand for copper," said a metals trader based in Singapore.
* PRICES: London aluminium rose 0.6 percent, while zinc advanced 0.4 percent. Shanghai aluminium ended up 0.4 percent.
* U.S. HOME SALES: U.S. home sales fell more than expected in March as rising demand stoked by declining mortgage rates and slowing house price inflation continued to be frustrated by a lack of properties, especially in the market's lower-priced segment.