Copper prices made further gains in Friday's trading on the London Metal Exchange (LME), hitting peaks last seen nearly 16 years ago because of Chilean supply worries, Chinese interest and fund buying, dealers said.
Three months ended at $3,145 a tonne, a gain of $99 on Thursday and the highest since January 1989.
Copper peaked at an all-time high on January 24, 1989 at $3,280.
Traders said the rampant trend in copper - since midweek prices have hurdled the long-standing March peak of $3,055 with ease - showed no sign of ending, although volumes were not particularly large and a correction could take place.
Roy Carson of LME broker Triland Metals Ltd, said: "Clearly on a reaction, values also have the potential to slide sharply, with first important support only at $3,045/60.
Ingrid Sternby, analyst with Barclays Capital, said the latest push higher had been primarily encouraged by technically driven CTAs (commodity trade advisers).
Business may well become jumpy in the coming sessions given that the annual LME dinner week starts on Monday, affecting liquidity, with many participants travelling.
Chile's state-owned copper producer Codelco and a union at its largest division failed to settle a contract dispute by a Thursday deadline, setting the stage for a strike on Friday, a union spokesman said.
The supervisors' union at Codelco Norte said the strike would paralyse the smelter and sharply reduce the division's output after two or three days.
But Codelco said its contingency plan would allow it to fulfil its supply contracts and meet its own production goals. Codelco Norte includes the Chiquicamata and Radomiro Tomic mines, as well as a smelter and refinery.
Lead, which hit $980 overnight, ended at $975, up $16, while zinc rose $21 to $1,171/172.
Aluminium gained $30 to $1,880, while nickel jumped $700 to $17,000. Tin was $115 higher at $9,190.