Swiss banking giant Credit Suisse said today that annual net profit for 2010 plunged 24% to 5.1 billion francs (€3.4 billion), amid a weak performance by its investment bank unit.

The group said income generated by its investment bank reached 3.5 billion francs for the year, almost half of what was posted in 2009. This also reflected a one-fifth drop in revenues recorded by the unit.

Private banking also recorded a drop of 6% in income before taxes, reaching 3.4 billion francs.

With tougher banking regulations governing capital due to set in, the bank said it was cutting its target on return to equity from 18% to 15%. Return on equity reached 14.4% in 2010.