FTSE down nearly 2 percent as Britain's banking index hits seven-year low

By Sudip Kar-Gupta and Atul Prakash LONDON (Reuters) - Britain's top share index slumped on Thursday, with a sharp sell-off in major banking and mining stocks pushing the market down to its lowest level in more than three years. The blue-chip FTSE 100 index fell 1.9 percent to 5,564.89 points in later afternoon trading after falling to 5,499.51 points, the lowest level late 2012. "Earnings results from some big banks have done little to revive investors' confidence." HSBC and Standard Chartered,