The US-listed bank reported a steep hike in net income for Q4 2015 on Friday, while private banking revenues also rose.

Private bank revenues inched up 3 per cent year-on-year at Citi to $691 million in the final quarter of 2015, driven by higher loan and deposit balances.

Citigroup reported net income of $3.3 billion for the fourth quarter of 2015, or $1.02 per diluted share, on revenues of $18.5 billion. This compared to net income of $344 million, or $0.06 per diluted share, on revenues of $17.9 billion for the same period a year ago.

"Overall, we had strong performance during 2015. The $17.1 billion we generated in net income was the highest since 2006, when our company was very different in terms of headcount, footprint, mix of businesses and assets,” said chief executive Michael Corbat.

Citigroup's operating expenses decreased 23 per cent to $11.1 billion in the fourth quarter of 2015. In constant dollars, operating expenses fell 19 per cent, mainly driven by lower legal and related expenses and repositioning costs, the firm said.

Operating expenses in Q4 2015 included legal and related expenses of $411 million, compared to $2.9 billion in the prior year period, and $313 million of repositioning charges, compared to $655 million in the prior year period.