A branch of Citibank in New York is shown. Citigroup Inc reported a surprise first-quarter profit of US$4.4 billion yesterday. [Shanghai Daily]

Citigroup Inc. provided more evidence that America's big banks may have turned a corner. The bank reported a surprise first-quarter profit yesterday as trading revenue offset losses from failed loans.

Citigroup said it earned US$4.4 billion after payment of preferred dividends, compared with a loss of US$696 million a year earlier. That was the bank's biggest quarterly profit since the second quarter of 2007.

The company cited strong trading of bonds, stocks and other securities for its big profit. Citigroup, one of the hardest hit banks during the credit crisis and recession, said loan losses fell for the third consecutive quarter. The amount of money it set aside for loan losses also fell.

Citigroup earned 15 cents per share on revenue of US$25.4 billion. That easily beat analysts' expectations of a slight loss, according to Thomson Reuters.