Barclays said its key investment bank arm ended last year with its worst quarter for three years as the euro zone debt crisis hit bond trading activity, dragging the British bank's annual profit down on the year before.

Barclays, Britain's fourth-biggest bank by market value, on Friday reported a pretax profit of 5.9 billion pounds ($9.4 billion) for 2011, down 3 percent on the year and below analysts' forecast of 6.1 billion, according to a company poll.

Income at investment bank arm Barclays Capital fell to 1.8 billion pounds in the fourth quarter, down 19 percent on the previous three months. – Reuters