- Three-month copper on the London Metal Exchange rose 0.3% to $9,497.50 a tonne by 0614 GMT, up 0.3% on a weekly basis
London copper prices advanced on Friday, on track for a weekly gain, after workers at two mines in top producer Chile went on strikes, raising supply disruption risks.
Three-month copper on the London Metal Exchange rose 0.3% to $9,497.50 a tonne by 0614 GMT, up 0.3% on a weekly basis.
The most-traded September copper contract on the Shanghai Futures Exchange eased 0.5% to 69,870 yuan ($10,785.74) a tonne.
On Thursday, two unions at Codelco's Andina copper mine walked off the job after rejecting the latest contract offer, while workers at JX Nippon Copper's Caserones mine also went on a strike after labour contract talks collapsed.
"The copper and aluminium markets have been tightened by supply constraints in Chile, Peru and China," said Fitch Solutions in a note.
However, capping further gains in copper prices was news that workers at Chile's sprawling Escondida copper mine, the world's biggest, approved a new contract with management, avoiding a strike.
Slowing demand in China also dented outlook for base metals, but potential supply outages caused by renewed global COVID-19 outbreaks poses an upside risk to the sector, Fitch Solutions said.
LME aluminium rose 0.1% to $2,584.50 a tonne, while nickel fell 0.6% to $19,555 a tonne.
ShFE aluminium eased 0.3% to 20,050 yuan a tonne, nickel increased 1.1% to 146,250 yuan a tonne while zinc fell 1.6% to 22,340 yuan a tonne and tin dropped 1.8% to 237,550 yuan a tonne.
Yangshan copper premium rose to $65 a tonne, its highest since March 23, indicating improving demand to import the metal into China.
The discount of LME cash copper on the three-month contract expanded to $31.75 a tonne, its biggest since July 20, indicating more nearby supply, as LME copper stocks surged 123% from end-2020 to 235,775 tonnes.