Stocks in London closed sharply down on Wednesday on a set of poor US economic data that suggested weaker activity could extend into the third quarter. The FTSE 100 index of top shares ended down 2.34 percent at 5,584.51 points.In the United States, the Institute for Supply Management said its non-manufacturing purchasing managers\' index slipped to 52.7 in July from 53.3 in June.Forecasters surveyed by Dow Jones Newswires had expected last month\'s PMI to be little changed at 53.5 points.Lloyds Banking Group (LBG) was the most traded stock of the day with 180 million shares changing hands, followed by Vodafone, which saw 149 million shares switching owners. Silver producer Fresnillo was the best blue-chip performer for the second straight day, rising 5.18 percent -- 94 pence -- to finish at 1,907, followed by consumer goods packaging firm Rexam, which climbed 4.01 percent -- 14.2 pence -- to close at 368.Swiss-based global commodities trader Glencore led the fallers, slipping 7 percent -- 32.1 pence -- to close at 426.35.It was followed by oil and gas exploration company Tullow Oil, which was down 5.68 percent -- 69 pence -- to finish at 1,146.On the currency markets, a pound was worth 1.640 dollars at 1604 GMT, up from 1.628 at the same time Tuesday, while it stood at 1.1459 euros, up from 1.1453 over the same period.