London copper was largely unchanged on Tuesday to trade around a four-month high as an improved global economic outlook supported prices, while aluminium dipped after climbing to a two-month top in the last session.

Economic optimism and expectations of a recovery in top consumer China have buoyed copper prices, which have gained 4.5 per cent in December, the biggest monthly rise since September last year.

Three-month copper on the London Metal Exchange was almost flat at $7,376 a tonne by 0708 GMT. Copper climbed to $7,415.50 a tonne on Friday, its highest since August 16.

The most-traded March copper contract on the Shanghai Futures Exchange eased 0.1 per cent to 52,280 yuan a tonne.

"It has got that bullish feel,” said Jonathan Barratt, chief executive of commodity research firm Barratt’s Bulletin in Sydney. “I wouldn’t be surprised to see copper break out in the first quarter to $8,000 and $8,300.” Copper is also drawing support from a lack of readily available refined metal due to falling exchange stocks.

LME data on Monday showed copper stocks in exchange-registered warehouses extended their recent decline, dropping to 367,450 tonnes, the lowest since January.

Still, the red metal is down 7 per cent in 2013 and ample copper concentrate expected to flow into the market next year could cap gains.

The large supply situation was reinforced on Monday when top copper producer Chile said its output rose 7.6 per cent in November.

Aluminium touched its highest level in nearly two months on Monday as consumer buying boosted the market in thin conditions.

On Tuesday, three-month aluminium on the London Metal Exchange slid 0.4 percent to $1,814 a tonne. It climbed to $1,839 a tonne in the previous session, the strongest since November 4.