Citigroup’s securities and banking unit underperformed its rivals in 2012 by posting the steepest drop in profits among the Wall Street banks to report full-year results so far, with trading revenues in the final three months falling to their lowest levels of the year.

The US bank today said that net profits in its securities and banking unit fell 10% last year to $4.38bn, down from $4.87bn in 2011.