The price of copper has reached a 16-month high as strikes loom at two copper mines in Chile.
Copper on the London Metal Exchange traded above $US7,300 per tonne on Wednesday - its highest level since September 2008.
The BBC reports investors expect demand for the metal to be strong in the new year.
Strikes at the Chuquicamata and Mina Sur mines in Chile are due to begin on 4 January.
Workers there want pay increases, prompted by the rise in global copper prices.
The Chuquicamata mine produces around 4% of the world's copper, according to RBC Capital Markets, and is expected to produce 565,000 tonnes of copper this year.