UPDATE: FTSE follows US markets deep into the red

The FTSE 100 was down 171.40 points to 5,075.59 as UK investors reacted to sell-offs in the US following the first opening bell after Standard & Poor's downgrade of the country's credit rating. In a move which has divided commentators and investors, S&P's became the first ratings agency to downgrade the US' prized AAA-rating. In response Wall Street opened lower, with the Dow Jones off 2% or 227 points, at 11,217 points, and the S&P 500 down 1.8% or 21.8 points, at 1,177.5. By 4pm the Dow had dropped 358.78 points to 11,085.83, a fall of 3.15%. Shares across Europe also remained...