text: The main feature was a drop in bank shares.
  That came after the news that Deutsche Bank faces a $14bn penalty to settle an investigation by US regulators into the mis-selling of mortgage-backed securities.
  Shares in RBS fell by 4.4%, Barclays by 2.8% and Standard Chartered by 2.7%.
  Neil Wilson, from ETX Capital, said the Deutsche case could have serious implications for RBS which was "among a number of European institutions that could face similar claims from the US Department of Justice", he said.
  "RBS could have to pay up to $13bn to settle the claims.
  "Even a third of this figure could deliver a crippling blow to the lender, making its return to profitability even further off. It would also derail plans to return the bank to private ownership any time soon," Mr Wilson added.
  Among the main risers in London were TUI, up nearly 4%; Shire, up 3.2%; and Burberry, up 3%.
  On the currency markets, the pound fell 1.2% against the dollar to $1.309 and dropped 0.4% against the euro to â‚¬1.1730.
target: (Close): London share prices fell back slightly, with the FTSE 100 index closing 20 points lower at 6,710, a fall of just 0.3%.