The results fell short of analysts' estimates, sending Citi's stock down 5.5 percent to $4.85 in heavy trading. Other banks also fell. Citi earned 4 cents per share, below the 7 cents analysts surveyed by FactSet were expecting.

The results were an improvement compared to the loss of $7.6 billion, or 33 cents a share, reported for the same quarter of last year. Revenue was $18.4 billion compared to $5.4 billion a year earlier.

For the year, Citigroup earned $10.6 billion on revenue of $86.6 billion. It's the first full year of profits for the bank since 2007.

More of Citigroup's customers were able to meet payments on credit cards and home loans. Its credit losses of $6.9 billion were down $805 million from the previous quarter, or 11 percent, marking the sixth consecutive quarter of declines. The reduced losses allowed the bank to release $2.3 billion from reserves it set aside for bad loans.

As expectations of an economic recovery have increased, the New York bank set aside $4.8 billion for future losses, its lowest level since the second quarter of 2007.