Reuters reported that London copper slipped after softer than expected growth in China's factories but losses were limited by hopes for fresh action to stimulate the economy in the world's top metals consumer.

Three month copper on the London Metal Exchange eased 0.41% to USD 7,384.50 per tonne by 0201 GMT reversing gains of half a percent in the previous session. Copper hit its highest in nearly a month last Wednesday at USD 7,480 per tonne.

It has clawed back around nine percent from 18 month lows below USD 6,800 touched on April 23 but is still down almost 7% for the year. The most traded September copper contract on the Shanghai Futures Exchange rose 0.19% to CNY 53,260 per tonne still below a 1 month peak of 53,770 reached in the prior session.

Ms Natalie Rampono a commodity strategist with ANZ in Melbourne said that "Yesterday's Chinese industrial production was still higher than March, but below market consensus. On the ground things are quite slow and market participants are starting to look at the possibility of China starting to ease monetary policy.”

China's factory output growth was surprisingly feeble in April and fixed asset investment slowed, rekindling concerns that a nascent recovery is stalling. Adding to metals headwinds, the dollar held firm near a five week high against a basket of major currencies on Tuesday after US retail sales data eased fears of a slowdown in the world's largest economy.

A firmer US unit makes dollar priced commodities such as metals more expensive for holders of other currencies. Rio Tinto Limited started scouting the North American spot market for raw material for its Kennecott copper smelter in Utah after a landslide at its nearby mine.

Which some traders said that may tighten the market for copper concentrate. However while India's biggest smelter owned by Sterlite Industries is shut on pollution concerns and is not buying concentrate, the impact may be muted. An Indian court is due to rule on whether Sterlite can reopen later this session.

A recent report that said sulphur dioxide emissions were within limits which could help lead to a ruling in favour of reopening the plant. More than half of India's total production was shut on March 30 after complaints about emissions. The shutdown is squeezing local supplies of refined copper and boosting prices in India.