Aluminium output in China the world's biggest producer of the metal is expected to grow by 14 per cent next year from this year.

The National Development and Reform Commission (NDRC) said that 2007 aluminium output will reach 10.5 million tons, up from 9.2 million tons estimated this year.

Meanwhile, China's demand for aluminium will rise by a slower pace of 13 per cent to 9.6 million tons, the NDRC said.

The rapid output growth, compounded by China's curbs on aluminium exports, will tame the ascending prices of the metal in the domestic market next year, according to the NDRC and analysts.

At the beginning of this year, China levied a 5 per cent tariff on aluminium exports. The tariff was elevated to 15 per cent in November. One impetus for the tariff increase is that aluminium production consumes large amounts of electricity while the nation needs to save energy to ensure sustainable economic growth.

Liu Defei, from the Beijing-based metal industry consultancy Antaike Information Development Co Ltd, said: "Aluminium exports will continue to decline next year as a result of the tariff increase, which will add supply in the home market and bring down prices slightly."

China's aluminium exports dropped by 26.9 per cent year-on-year to 720,000 tons in the first 10 months of this year.

Aluminium prices in China have risen during recent years, buoyed by high costs and strong demand at home and abroad. Domestic prices now hover between 21,000 yuan (US$2,690) and 22,000 yuan (US$2,810) per ton, up 10 per cent from the beginning of this year.

The NDRC said: "Possibilities of a steep fall in aluminium prices could not be ruled out if international hedge funds pull out of the aluminium futures market next year." It stressed that hedge funds' massive buying into aluminium futures was another cause of the bullish prices this year.

The NDRC warned of a possible resurgence of overheated investment in the aluminium sector and expansion of production capacity in China motivated by strong demand and tumbling costs of alumina, the raw material used to make the metal.

"We should notice that the zeal of some enterprises and local governments to build new aluminium production capacity is on the upswing," the NDRC said.

It said it will join forces with environmental, land and financial regulators to intensify measures next year to prevent aluminium production capacity from expanding too rapidly.

There are more than 90 aluminium plants in China with a combined production capacity of 10 million tons.

The NDRC also said it will form supportive policies to boost consolidations between aluminium and alumina producers in an effort to quench alumina companies' thirst to build new aluminium capacity.

Alumina prices in China have declined sharply this year because of bloated production at home and abroad.Currently, the price stands at 2,400 yuan (US$307) per ton, which the NDRC said is a "normal" level, down from a staggering 6,000 yuan (US$767).

An official from the China Non-Ferrous Metal Industry Association predicted yesterday that alumina production in the country would jump to 13 million tons this year from 8.5 million tons in 2005.