‘In lead and zinc you have the supply disruptions at Xstrata underpinning prices and in copper, the strike at Southern Copper gives support,’ analyst Michael Widmer at Calyon said.

Workers at Southern Copper went on an indefinite strike on Tuesday for higher pay, affecting Southern’s Cuajone and Toquepala mines which produce 370,000 tonnes of copper annually, and its 350,000-tonne Ilo smelter.

Southern Copper Chief Executive Oscar Gonzalez told Reuters that if the strike dragged on it could cut 2007 output by 10 percent.

Three-months copper was up $105 at $8,265/8,285 a tonne at 0945 GMT, after hitting an intra-day peak at $8,280.25 on Tuesday, its highest since May 4 when it touched $8,335.

Lead hit an all-time at $3,585 before trading at $3,575/3,595, up $60 from the previous session’s close.

Ongoing supply tightness is affecting the lead market and Swiss-based miner Xstrata said a fire at its Mount Isa zinc-lead concentrator in Australia will impact about 15,000 to 20,000 tonnes of lead.

Stocks of lead, mainly used in the battery industry, stand at 22,350 tonnes—around one day’s global consumption and down from 54,950 in October last year.

Zinc gained $60 at $3,120/3,140 from Tuesday.

‘In zinc, you still have inventories coming off and the lack of Chinese exports help driving prices above $3,000,’ Calyon’s Widmer said.

Stocks in LME warehouses fell by 450 tonnes to 60,275, down from 394,100 at the beginning of this year.

Volatility

A trader in Hong Kong said investors would be tempted to sell copper towards $8,250, but added: ‘There is no liquidity and next week will be volatile. Sheer weight of cash could send copper to $9,000, although I don’t think that can be sustained.’

Shanghai is closed all this week for National Day celebrations and South Korea is shut for a public holiday.

Next week is the London Metal Exchange dinner—where metal consumers, producers and analysts gather for a series of meetings, seminars and cocktail receptions—and in the past it has coincided with very significant price moves.

The copper premium for cash metal above the benchmark futures contract widened to $78 a tonne, up from $42 just two weeks ago.

This may suggest that nearby supplies are tight, but the situation is set to ease according to the International Copper Study Group, which predicted a copper market surplus of 110,000 tonnes in 2007 and 250,000 tonnes in 2008.

The Lisbon-based ICSG said world refined copper output in 2007 is projected to rise 4.4 percent to 18.12 million tonnes this year and by a further 4.6 percent to 18.95 million tonnes next year.

Nickel rose $500 or 1.6 percent at $31,200/31,400.

‘Nickel seems to have established a new range with $30,000 support and resistance at $34,500,’ said analyst Edward Meir at Man Financial.

‘At $35,000 there is a double top and the market would need to burst through there to get funds’ juices flowing again.’

Three-months aluminium gained $12 to $2,500/2,505.