FTSE 100 Index, British benchmark stock market gauge, Friday dropped by 0.62 percent, or 38.05 points, to 6117.76, as British construction output witnessed a surpirsing dip in July.
Official data showed that British construction output fell by 1.0 percent on the month in July 2015, worse than economists' forecasts of a 0.5 percent pick-up after an unrevised 0.9 percent rise in June.
Most sectors of London market closed lower Friday, with Industrial Metals & Mining, Food & Drug Retailers and Fixed Line Telecommunications sectors leading the losers.
WM Morrison Supermarkets' share price slumped by 3.34 percent, topping the losers of the blue chips.
Share prices of Inmarsat, J Sainsbury, Tesco and BT Group declined by 2.48 percent, 2.30 percent, 2.26 percent and 2.19 percent respectively.
BAE Systems led the top gainers of the blue chips with a share price increase of 1.92 percent, followed by Hikma Pharmaceuticals (1.69 percent), Kingfisher (1.39 percent), Coca-Cola HBC (1.20 percent) and Rio Tinto (1.76 percent).
The trading volume in FTSE 100 companies was around 7 percent less than its 30-day average. And the index has lost 3.77 percent so far this year.
The broader FTSE All-Share Index lost 0.54 percent.