Citigroup Inc. (C - Get Report) , the third-biggest U.S. bank, posted a fourth-quarter profit that beat analysts' estimates, with CEO Michael Corbat cutting costs as revenue slid. 

Net income was $4.3 billion, the New York-based bank said Monday in a statement. Earnings per share were $1.64, while adjusted profit of $1.61 beat the average analyst estimate of $1.55 in a FactSet survey. The results were difficult to compare with those in the fourth quarter of 2018, when Citigroup booked a net loss of $18.9 billion because of a one-time charge related to the tax law passed in late 2017.

Revenue fell 2% from a year earlier, while expenses were cut by 4%.  

"A volatile fourth quarter impacted some of our market-sensitive businesses, particularly fixed income," Corbat said in the statement. The company "carefully managed both our expenses and balance sheet."

Revenue in the fixed-income division, which includes bond trading as well as foreign exchange and commodities, tumbled by 21% to $1.94 billion. The results were affected not only by the volatile markets but also by the underperformance of corporate bonds and other credit-sensitive securities.  

"People didn't know when to jump in, and therefore everybody just stayed on the sidelines," Citigroup Chief Financial Officer John Gerspach said on a conference call with analysts. 

Stock-trading revenue rose by 18% to $668 million, "reflecting the absence of an episodic loss incurred in the prior-year period," according to the press release. Excluding that loss, fourth-quarter 2018 revenue in the division would have been down by a low- or mid-single-digit percentage from a year earlier, Gerspach said on the conference call.  

Investment-banking revenue slipped by 1% to $1.278 billion, as revenue fell from underwriting stocks and bonds.  

The stock rose 4% to $58.93 at the close of trading on Monday.

Ken Usdin, an analyst at Jefferies, wrote in a report that while the company missed his revenue estimate, the shortfall was more than offset by lower-than-expected operating expenses and costs for bad loans.    

For the full year, Citigroup's adjusted net income rose by 14%. The key driver was a reduction in taxes due to the 2017 law, since pretax profit from continuing operations climbed just 3%.