Citigroup (NYSE:C) posted a mixed fourth quarter, with earnings beating expectations but revenue missing estimates on Wednesday.The bank reported fourth-quarter revenue (net of interest expense) of $19.87 billion, up 2$20.53 billion. Excluding divestiture-related impacts tied to the planned sale of AO Citibank in Russia, revenue increased 8%.Net income declined 13% year over year to $2.5 billion, reflecting a$1.1 billion after-tax loss related to the Russ ...