Copper fell for a fourth day in London yesterday, on course for the biggest monthly drop since December 2008, as commodities and equities slid after Standard & Poor\'s cut the US credit rating. Tin reached an 11-month low. Zinc and crude oil paced declines as the S&P GSCI Spot Index of raw materials retreated for an eighth day in nine. The MSCI World Index of shares dropped for an eighth straight session, and futures indicated that US benchmarks will fall when trading starts in New York. Group of Seven and Group of 20 leaders said they are ready to stabilise financial markets. Markets adjusting Article continues below \"The markets are adjusting to the deteriorating economic backdrop that threatens the demand side of the fundamentals for the metals,\" William Adams, an analyst at Basemetals.com in London, said in a report yesterday. Copper for three-month delivery fell $80 (Dh293), or 0.9 per cent, to $8,961 (Dh32,913) a metric tonne by 10.30am yesterday on the London Metal Exchange (LME). Prices reached $8,950 (Dh32,872) the lowest level since June 27, and are down 8.8 per cent in August. LME prices dropped below $9,000 (Dh33,056) a ton for the first time since June 28. Still, they\'re unlikely to fall \"much below $8,500 [Dh31,220],\" said David Thurtell, Singapore-based head of metals research at Citigroup. \"The S&P credit-rating downgrade of the US won\'t have lasting implications for commodity markets,\" he said.