Bank of America Corp posted a lower quarterly profit on Friday, hurt by a surge in troubled loans as more credit card and mortgage customers fell behind on payments.

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 7 percent to $3.22 billion.

Net revenue rose 61 percent to $32.77 billion, helped by the acquisition of Merrill Lynch & Co.

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

Difficult challenges lie ahead from continued weakness in the global economy, rising unemployment and deteriorating credit quality that will affect our performance for the rest of the year and into 2010, Chief Executive Kenneth Lewis said.

Results included a gain from selling part of its stake in China Construction Bank Corp. Results also included $713 million of dividend payments tied to a federal bailout, and a charge to bolster a federal deposit insurance fund.

Bank of America shares rose 7 cents to $13.24 in premarket trade. Through Thursday, the shares had fallen 6 percent this year, compared with a 14 percent drop in the KBW Bank Index.

(Reporting by Jonathan Stempel; editing by John Wallace)