* U.S. lawmakers work on rival bills as Aug. 2 deadline looms * Slow Chinese buying interest trapping copper in tight ranges * Coming Up: ECB Governing Council member Costa speaks; 0800 GMT (Adds details, updates prices) By Manolo Serapio Jr SINGAPORE, July 25 (Reuters) - London copper edged lower on Monday as investors worried about a looming U.S. debt default with no sign of a deal among lawmakers to avert it, although supply risks due to a strike at the world's top copper mine capped losses. Unable to compromise on how to cut the U.S. budget deficit and raise the country's borrowing authority, U.S. lawmakers are now working on competing bills, heightening the prospects for a catastrophic U.S. debt fault. As of Sunday, there were no signs of a deal emerging to head off a default in eight days that could trigger global economic calamity and strip the United States' of its coveted Triple-A credit rating. The U.S. needs to increase the $14.3 trillion U.S. debt ceiling by Aug. 2. "Copper is consolidating at current levels. Consumption isn't particularly active," said Zhou Jie, analyst at Shanghai CIFCO Futures. "Since the external environment is rather murky, price moves will hinge on the commodity's fundamentals." Three-month copper on the London Metal Exchange eased $37 to $9,638 a tonne by 0340 GMT. It ended nearly flat last week. Third month copper on the Shanghai Futures Exchange SCFcv1 dropped 0.9 percent to 71,530 yuan per tonne. "We find that the more copper prices go above $9,000, the slower the market becomes," said a Hong Kong-based trader. "China doesn't like to pay high prices. They can afford to wait so they will." "And with the outcome of what's going on in the U.S. still unclear, people are not prepared to make any big bets." But a strike at Chile's Escondida, the world's biggest copper mine, which highlighted supply risks in a market already expected to be in shortage this year, helped counter worries on the U.S.' debt situation. The strike at Escondida entered a third day on Sunday with no sign of a deal to end a protest unions are threatening to extend across the country. Mine owner BHP Billiton said the strike was illegal and that it was putting in place a plan to secure its operations. Rising supply risk due to industrial action "will likely remain a theme for the rest of the year or as long as copper prices remain high", said a trader in Singapore. The world's refined copper market saw a deficit of 69,000 tonnes in January to April, the International Copper Study Group said last week, and analysts expect the shortage to widen for the rest of the year. Base metals prices at 0340 GMT Metal Last Change Pct Move End 2010 YTD pct chg LME Cu 9638.00 -37.00 -0.38 9600.00 0.40 SHFE Cu* 71530.00 -660.00 -0.91 71850.00 -0.45 LME Alum 2577.25 -13.75 -0.53 2470.00 4.34 SHFE Alum* 17655.00 15.00 +0.09 16840.00 4.84 COMEX Cu** 437.90 -2.55 -0.58 443.95 -1.36 LME Zinc 2460.00 -38.00 -1.52 2454.00 0.24 SHFE Zinc 18645.00 -145.00 -0.77 19475.00 -4.26 LME Nickel 23850.00 -100.00 -0.42 24750.00 -3.64 LME Lead 2690.00 0.00 +0.00 2550.00 5.49 LME Tin 28250.00 0.00 +0.00 26900.00 5.02 LME/Shanghai arb^ 1176 Dollar/yuan 6.4476 \ 6.4478 ** 1st contract month for COMEX copper * 3rd contact month for SHFE aluminium, copper and zinc ^ LME 3-m copper in yuan, including 17 pct VAT, minus SHFE third month (Additional reporting by Rujun Shen; Editing by Himani Sarkar)

Source