Copper retraced yesterday's strong gains as LME stocks edged higher, although prices continued to be underpinned by strong demand levels.

Copper stocks were up by 1,650 tonnes to 214,900 tonnes, said daily LME inventory data.

At 2.01 pm, LME copper for three-month delivery was down at 5,730 usd a tonne having risen 279 usd to settle at 5,749 yesterday.

"Fund buying is coming back in and copper is rising," said Standard Bank analyst Mike Skinner, adding that today's dip was "to be expected" because of profit taking.

While copper was moderately lower, all of the other base metals' prices were higher.

"Given the strong tone in the rest of the group, we don't think (copper)prices will stay down for long," said Man Financial analyst Ed Meir.

Aluminium prices jumped again as market players mulled supply threats from Guinea, West Africa, where worker unions resumed strike action.

The renewed strike disrupted bauxite mining, and bauxite and alumina shipments by Guinea, the world's leading exporter of the ore.

Aluminium was up at 2,845 usd a tonne against 2,820 usd at the close yesterday.

In other metals, tin extended gains from Monday after Indonesian tin producing company PT Koba Tin suspended shipments from Bangka, Indonesia, following an investigation into alleged illegal mining.

Tin was up at 12,770 usd a tonne against 12,595 usd at the close yesterday.

Lead was up at 1,700 usd a tonne against 1,675 usd at the close yesterday. Zinc was up at 3,225 usd against 3,220 usd while nickel rose to 37,350 usd against 36,000 usd.