That transaction, which closed at the end of June, led to the one-time gain of $626 million during the quarter.
Non-interest revenue, including card and travel commission fees, rose 4 percent to $7.34 billion.
American Express' provision for losses declined to 6 percent to $489 million.
Expenses edged higher as the company spent more on marketing and cardholder reward programs.
All told, American Express' profit increased to $1.52 billion, or $1.43 per share, from $1.39 billion, or $1.27 per share, in the same quarter a year earlier.
The average per-share estimate of analysts surveyed by Zacks Investment Research was for profit of $1.38.
The company said revenue rose 5 percent to $8.66 billion from $8.25 billion in the same quarter a year earlier. Analysts expected $8.67 billion, according to Zacks.
American Express shares tacked on 17 cents to $91.88 in after-hours trading. The stock closed down 15 cents at $91.71 in regular trading Tuesday.