LONDON, Dec 20, 2011 (Dow Jones) -- The decline in aluminum prices has already led to production cutbacks in China and will likely lead to more, providing a mildly bullish boost to the metal, U.S. bank Goldman Sachs (GS) said Tuesday.

The bank lowered its 12-month aluminum price forecast by 9.4% to $2,400 a metric ton from $2,650/ton previously, and kept its three-month outlook unchanged at $2,300/ton.

The price of aluminum, used in the automotive, aerospace and construction industries, has tumbled along with other commodity prices in recent weeks and is trading at 2011 lows below $1,900/ton on the London Metal Exchange.

Goldman Sachs said that at current Shanghai Futures Exchange prices, 15%-30% of aluminum supply in China, the world's largest producer of the metal, is either losing money or breaking even on a cash-cost basis.

"Consumers are likely to be considering locking in some 2012-13 supply," the bank noted. "With production falling significantly in China and further production set to be cut if prices stay at these levels, we concur with the mildly bullish sentiment towards aluminum."