LONDON — Copper prices slipped on Friday as worries about supply disruptions in Peru receded and as the market fretted about a slowing of demand in China, the world's largest consumer.

Copper for three-month delivery ended the day at $8,470 (U.S.) per tonne, down $185 from Thursday. The metal used in power and construction hit a record high of $8,940 a tonne in after-hours trading on Wednesday on concerns about supply disruptions because of a strike in Peru. Analysts say record high prices could discourage buying by users in China, which consumes about 25 per cent of global output.

“During the first half of the year physical buying has been pretty weak and that's largely a result of aggressive destocking by consumers,” said Gayle Berry, metals analyst at Barclays Capital.

“When the summer ends a lot of these consumers are going to be operating with very low stocks and that's when we think there is potential for another big move up in copper prices,” she said.

Copper inventories in Shanghai warehouses rose 12 per cent in the week ended Thursday to 36,175 tonnes, the exchange said.

Supply threats for copper receded as union support weakened for Peru's nationwide strike after workers at two more big mines decided to return to work and government officials said it was likely to end soon.

“The strike appears to be winding down ... so it is less supportive,” said analyst Leon Westgate at Standard Bank.

Lead traded down at $1,565 per tonne from $1,610 at the close on Thursday. Earlier the battery-making material lost 4.9 per cent to $1,531 – the lowest since Feb. 8, 2007.

Lead extended the previous day's losses, when it dropped 6 per cent, as investors worried about oversupply in the market.

“Lead has been suffering badly since the second quarter but its price depreciation is directly linked to the stark increase in inventories,” a LME trader said.

Inventories of lead in LME warehouses rose by 175 tonnes to 100,675, more than double the level in January and the highest in almost two years.

Zinc edged down $3 to $1,780 per tonne after hitting $1,750, its lowest level since December, 2005.

“It just keeps sinking,” Ms. Berry said, adding that Barclays had been recommending for some time that clients short zinc – bet on lower prices in the future.

“Fundamentally there is no reason to be long zinc. It's a market that is looking very well supplied this year and it's already in surplus,” she said.

Nickel slipped to $20,500 per tonne, its lowest in more than two years and closed at $20,550/20,600 a tonne, down $300 from Thursday.

Aluminum traded down at $3,168 a tonne from $3,184. On Thursday it reached $3,229 – the highest level since March 7. Tin was lower at $22,400/22,405 a tonne from $22,850.