(Reuters) - Copper prices edged lower on Tuesday, as a weak global economy weighed on the demand outlook for industrial metals, but further falls were kept in check by expectations top consumer China will embark on pro-growth policies to stimulate its economy. Benchmark copper on the London Metal Exchange slipped to $8,173 a metric tonne at 0916 GMT, down 0.1 percent from a last bid of $8,180 on Monday, but prices rebounded from a one-week low of $8,128 hit in the previous session. Reinforcing concerns about growth, the IMF said late on Monday the global economic slowdown is worsening as it cut its growth forecasts for the second time since April and warned U.S. and European policymakers that failure to fix their economic ills would prolong the slump. The warning pushed European shares lower and the euro fell against the dollar on debt concerns, putting pressure on metals priced in the U.S. unit. "We have an overall risk aversion in markets and a stronger U.S. dollar is also dragging on metals prices," said Eugen Weinberg, head of commodity research at Commerzbank. "Sentiment and prices are still very downbeat and I wouldn't be surprised if prices rally towards the end of the year on better liquidity and improving economic sentiment." Copper prices have rallied more than 8 percent since the start of September, fueled by the third round of quantitative easing (QE) by the U.S. Federal Reserve, the promise of bond buying by the European Central Bank (ECB) and stimulus measures in Japan and China. Further falls were prevented by expectations China would roll out additional stimulus measures to bolster the economy and spur demand for the metal used in power and construction. "Losses in base metal prices will be capped despite weak fundamentals and global economic worries, as investors expect Beijing to do the necessary fine-tuning to stabilize the economy before the 18th Communist Party Congress," said CIFCO Futures analyst Zhou Jie, referring to China's leadership transition event scheduled on November 8. CHINA DATA EYED In China, which consumes 40 percent of global refined copper, traders returned to the market this week from a week-long national holiday to find few signs of demand improving. "China's copper demand appeared sluggish after traders returned to the market, with spot prices trading at a discount of 150 Yuan/t to SHFE front-month futures," ANZ analysts said in a note. Investors will eye China's third-quarter growth data at the end of next week, which analysts expect to show the weakest three months of the year. China is also expected to announce export-import data for September on Saturday. In industry news, global miner Rio Tinto (RIO.L) cut its growth forecast for China and said it was stepping up efforts to cut costs. It also expects copper production across the group to increase from 2013, thanks to improving grades at existing mines and the start of production at Oyu Tolgoi, forecasting a cumulative annual growth rate of 13 percent from 2011 to 2015. Concerns about the lingering debt crisis in the euro zone also kept metals prices soft. Greece will miss the five-year debt reduction target that underpins the country's 130 billion euro bailout, according to forecasts released by one of its main lenders on Tuesday. Three-month aluminum slipped to $2,068.25 a tonne from a close of $2,082.50 on Monday, and battery metal lead edged down to $2,256 from $2,260 at the close on Monday. Tin fell to $22,040 from $22,100 and zinc was at $2,032.50 from $2,035. Stainless steel material nickel was at $18,089 from a last bid of $18,070 on Monday.

Source