Copper rose the most in more than six months in London on speculation that demand from Chinese buyers will keep expanding. Lead advanced to a record and tin reached its highest in 17 years.

Copper trading on the Shanghai Futures Exchange will resume on Feb. 26 after the weeklong Lunar New Year holiday. Chinese imports of copper and copper products jumped 44 percent in January from a year earlier, customs data showed Feb. 12. Chinese refined-copper imports in January were about 132,000 metric tons, almost double last year's average monthly imports of 69,000 tons, Macquarie Bank Ltd. said Feb. 19.

``We expect to see, post the Chinese New Year, more activity by Chinese buyers in the copper market,'' said Daniel Brebner, an analyst at UBS AG in London. ``We do expect to see considerable strength in copper over the next quarter or so.''

Copper for delivery in three months on the LME advanced $280, or 4.8 percent, to $6,070 a metric ton as of 2:21 p.m. local time. The contract earlier rose as much as 5.4 percent, the biggest intraday gain since Aug. 4. Today's gain pared this year's losses to 4.1 percent.

Copper edged down amid light selling and quiet trading conditions with Chinese players on a week-long holiday celebrating the Lunar New Year.

Tin hit a new contract high of 13,450 usd a tonne amid falling inventories and continued concerns over supply disruptions in Indonesia.

At 12.57 pm, LME copper for three-month delivery was down at 5,740 usd a tonne having shed 5 usd to settle at 5,805 yesterday.

'There's a relative lack of buying interest partly because of the Chinese holiday,' said Triland analyst, Roy Carson.

Copper retraced yesterday's strong gains as LME stocks edged higher, although prices continued to be underpinned by strong demand levels.

Copper stocks were up by 1,650 tonnes to 214,900 tonnes, said daily LME inventory data.

At 2.01 pm, LME copper for three-month delivery was down at 5,730 usd a tonne having risen 279 usd to settle at 5,749 yesterday.

'Fund buying is coming back in and copper is rising,' said Standard Bank analyst Mike Skinner, adding that today's dip was 'to be expected' because of profit taking.

While copper was moderately lower, all of the other base metals' prices were higher.

'Given the strong tone in the rest of the group, we don't think (copper)prices will stay down for long,' said Man Financial analyst Ed Meir.

Aluminium prices jumped again as market players mulled supply threats from Guinea, West Africa, where worker unions resumed strike action.

The renewed strike disrupted bauxite mining, and bauxite and alumina shipments by Guinea, the world's leading exporter of the ore.

Aluminium was up at 2,845 usd a tonne against 2,820 usd at the close yesterday.

Copper edged lower as traders focused on yet another rise LME inventories, overlooking data out earlier showing Chinese imports of unwrought copper and semi-finished copper products rose 44 pct in January over December.

At 1.15 pm, LME copper for three-month delivery was down at 5,540 usd a tonne against 5,580 usd at the close Friday.

Neil Buxton, managing director of GFMS Metals Consulting, said the market is not too worried about the rise in Chinese imports because global inventories are rising at the same time.

'There seems to be sufficient production available for the market to absorb higher Chinese demand,' he said.

The LME said in a daily report earlier inventories held in its warehouse rose by 425 tonnes to 216,050 tonnes. LME stocks have more than doubled since the start of last year.

Buxton said he expects copper might edge higher this week because there are some supportive factors in the market such as the possibility of strike action at Southern Copper's smelter in Peru.

A union at the smelter has set a strike deadline for Feb 19. It is expected to enter into new talks with Southern Copper this week.

'I think in the short term we might see some upward movement but I think there has to be quite a lot of bullish news around to turn around the overall downtrend in copper,' Buxton said.

Tin surged to 12,550 usd a tonne, after hitting a new all-time high of 12,750 usd earlier, after newswires reported at the weekend three directors at tin miner PT Koba Tin had been arrested on counts of illegal tin mining.

The company has also suspended shipments from the island of Bangka in Indonesia.

'I think the critical point is ... there aren't any other producers that can fill the gap being left by lower Indonesian production so further spikes don't come as a surprise,' Buxton said.

Separately, tin remains supported by news out Friday the Bolivian government has seized control of a tin smelter complex owned by Glencore.

In other metals, nickel was up at 36,390 usd a tonne against 36,150 usd, zinc rose to 3,140 usd from 3,130 usd, aluminium edged up to 2,702 usd against 2,700 usd while lead climbed to 1,660 usd from 1,615 usd.

The Zambian government proposed Friday to raise a tax on mining companies, aimed at helping the copper-rich but impoverished nation cash in on high global copper prices.

Finance Minister Ng'andu Magande said the government planned to negotiate with the mining companies on tax revisions.

But more than 70 percent of the population still lives in poverty, which has led to frustration with policies of recently re-elected President Levy Mwanawasa, evidenced in last year's bitter presidential elections. The distribution of copper benefits has become a key element of that debate.

Magande said the government wants to increase the country's royalty tax on copper earnings from 0.6 percent to 3 percent, increase the company income tax from 25 to 30 percent, and reintroduce a 15 percent withholding tax on dividends, interest, royalties and other mining sector transactions.

The existing 0.6 percent royalty tax, which is particularly low compared with taxes in other copper-producing countries, was put in place during an industry downturn early in the decade, when the Zambian government was desperate to attract foreign investment. Copper accounts for more than 60 percent of the southern African nation's exports.

Copper prices have since risen from less than US$1 per pound to more than US$3 per pound (about €5 per kilogram), driven in large part by growing demand from China. Zambian copper production rose by 7.9 percent in 2006, Magande said, from 459,324 metric tons to 492,016 metric tons. The mining industry now directly employs almost 50,000 people in Zambia, he said.

"At the time when copper prices on the international market were low, mining companies were offered tax concessions in order to make their projects viable," Magande said in prepared remarks. "Now that the prices are high, there is need to review these concessions so that the nation can benefit from increased earnings from the mining companies."

Talk of revising the copper tax has raised fears, however, of a backlash among foreign mining companies many of which entered into long-term contracts with the government.

Magande said the government would now seek negotiations with those companies "so that there is mutual consent by contracting parties to revise the tax regime to the new rates."