Shanghai Futures Exchange copper stocks are expected to rise by 3,000-4,000 tonnes this week, and zinc inventories are also seen up after last week's 24 percent surge.

The range of views varied from 3,000 tonnes to as much as 10,000 but the bulk of the six analysts and traders polled expected a rise of 3,000 to 4,000 tonnes when weekly data is released after the market closes on Friday.

"We are looking for a rise of around 3,500 tonnes. The physical business in China is still pretty slow. Spot is at a slight discount to futures -- not enough to attract a lot of metal but maybe enough to deter buyers taking from the exchange," a merchant in Singapore said.

Spot copper traded in Shanghai at around 50,800 yuan a tonne on Friday, while front-month copper on the ShFE SCFc1 was 51,000 yuan, with just about a week to go before the contract expires.

Last week copper inventories in warehouses monitored by the Shanghai Futures Exchange rose 7 percent from a week earlier, to 102,835 tonnes, around 1,400 tonnes short of September's five-year high. Zinc inventories soared to an all-time high of 145,536 tonnes from 117,706 tonnes.

Zinc stocks were expected to rise, with metal attracted into warehouses by stronger prices in the futures market and the chance of earning the contango of more than 300 yuan between the first and third month contracts. SZNc1 SZNc3 But last week's big delivery was mostly overlooked by speculators.

"Shanghai exchange zinc stocks are largely ignored, because stocks outside the exchange are huge," said a Shanghai-based trader.