Bank of America Corp, the largest U.S. bank, posted a quarterly profit that topped Wall Street forecasts but warned of a fresh surge in soured loans to credit card, mortgage and business customers.

Soaring credit losses may add to pressure on Chief Executive Kenneth Lewis as the U.S. Congress and regulators ramp up scrutiny of the bank’s ability to manage risk and its controversial purchase of Merrill Lynch & Co, and that tough economic conditions could hurt results into 2010.

“Growth in charge-offs and nonperforming assets still scares the daylights out of me,” said Paul Miller, an analyst at FBR Capital Markets in Arlington, Virginia.

Second-quarter net income applicable to common shareholders fell 25 percent to $2.42 billion, or 33 cents per share, from $3.22 billion, or 72 cents, a year earlier.

Before preferred stock dividends in both periods, profit fell 5 percent to $3.22 billion. Net revenue on a taxable equivalent basis rose 60 percent to $33.09 billion.

Analysts on average expected profit of 29 cents per share on revenue of $33.26 billion, according to Reuters Estimates.

Lewis on a conference call predicted that “profitability in the second half of the year will be much tougher than the first half” because of an expected absence of one-time gains. Such gains helped boosted first-half net income to $7.47 billion.

Second-quarter results included an unspecified tax benefit and $9.1 billion of pretax gains from selling a stake in China Construction Bank Corp and putting a processing unit into a joint venture with First Data Corp. The bank took a $760 million charge to bolster a U.S. deposit insurance fund.