Bank of America posted a higher-than-expected quarterly profit Wednesday as growth in its consumer and wealth management arms underscored the bank’s progress in stitching together businesses it picked up in the financial crisis.

Profit at the bank’s largest unit, retail banking, soared 32 percent as revenue rose and credit costs fell. The unit includes parts of Countrywide Financial, the mortgage lender acquired by the bank in July 2008, and Merrill Lynch, the retail brokerage it bought in January 2009.

A key rationale for both of those deals was the ability to sell a wide range of consumer banking products to Merrill Lynch and Countrywide customers, executives said at the time.

The bank said it issued more than 1 million credit cards in the third quarter, the highest number since 2008, and nearly two-thirds went to existing customers.

“We feel like a lot of the work that we have been doing in that segment has paid off,” Chief Financial Officer Bruce R. Thompson told reporters on a conference call.

Profit at Bank of America’s wealth management business also rose in the quarter, up 26 percent to $719 million, thanks to record asset management fees.

Crisis-era acquisitions caused headaches for the bank, too. Its mortgage business lost $1 billion in the third quarter, compared with a loss of $857 million a year earlier. Countrywide has cost Bank of America more than $40 billion in litigation expenses and other charges linked to its bad subprime mortgages, and the bank set aside an additional $300 million for mortgage litigation in the latest quarter.

Merrill Lynch’s institutional sales and trading arm lost $778 million, up from a loss of $276 million in the same quarter last year, hurt by a 20 percent drop in fixed income, currency and commodities trading revenue, excluding an accounting adjustment.

But investors were hopeful about the results, and Bank of America shares rose 2.3 percent to $14.56.

“All of the past issues related to Countrywide are masking a very good, vibrant and attractive retail banking and credit card business,” said Joel F. Conn, president of Lakeshore Capital in Birmingham, Ala. “The issues will eventually go away. Today’s earnings appear to make that case.”

Bank of America earned net income for common shareholders of $2.22 billion, or 20 cents per share, in the third quarter, beating analysts’ average estimate of 18 cents per share. In the year-earlier quarter, the bank recorded a net loss for common shareholders of $33 million because of accounting adjustments, litigation expenses and tax charges.

Since Brian Moynihan became chief executive in 2010, one of the bank’s primary areas of focus has been slashing costs. In 2011, it announced its Project New BAC initiative, an effort to save $8 billion per year by the end of 2014. The bank said it is on track to achieve its goal of saving $1.5 billion per quarter by the end of this year.

Overall expenses were $16.39 billion in the third quarter, down $1.16 billion from a year earlier. Bank of America cut costs from its legacy assets and servicing business, which deals with bad mortgages. Excluding legal costs, expenses in that unit were $2.2 billion, down from $2.9 billion a year earlier. The bank is aiming for $2 billion a quarter by the end of the year.

Chief executives at most major U.S. banks are looking to cut costs because revenue growth is so slow. Citigroup chief executive Michael L. Corbat on Tuesday highlighted the bank’s expense controls, noting that it has more power over costs than revenue.

Bank of America experienced that pressure itself: Revenue fell 1.5 percent to $22.19 billion in the third quarter, excluding gains and losses from changes in the value of the bank’s debt.

Part of that decline came from a drop in mortgage lending revenue. The bank’s “core production” revenue from home loans fell to $465 million from $944 million in the same quarter last year.

Moynihan said on a conference call that the bank expects mortgage loan production to fall again in the fourth quarter. He said the bank would continue to reduce mortgage banking staff with the decline in volume.

“It’ll never be a huge business for this company,” given the competition and thin profit margins, Moynihan said.

— Reuters