BEIJING: China will strengthen commodity price monitoring and continue to release copper, aluminium, and zinc from its state reserves in batches, the National Development and Reform Commission (NDRC) said on Monday.

In a rare move aimed at cooling a rally in metal prices that has pushed up raw material costs for Chinese manufacturers, the state planner sold 20,000 tonnes of copper, 50,000 tonnes of aluminium, and 30,000 tonnes of zinc from its reserves on July 5.

More than 200 non-ferrous fabricators attended the bidding, with sales prices about 3-9% lower than market price that day, the NDRC spokesman Yuan Da said at a press briefing.

"The release initially achieved the expected goal ... targeted placement granted downstream fabricators an opportunity to replenish stocks and lower some companies' raw material costs," Yuan said.

The NDRC also pledged to keep reinforcing supervision of the futures and spot market and strictly crack down on irregularities such as hoarding, it said.

The most-traded Shanghai copper futures were down 0.7% at 68,720 yuan ($10,606.94) per tonne, as of 0256 GMT.

Shanghai aluminium futures fell 1% to 19,290 yuan, while zinc advanced 0.8% to 22,475 yuan a tonne.