American Express Co.’s net income grew 9 percent in the second quarter, as spending by cardholders increased and the credit card issuer set aside less money to cover potential credit losses. A one-time gain related to the company’s business travel division also helped boost results.

The New York company’s latest earnings beat Wall Street’s expectations, but its 5 percent increase in revenue fell short.

Spending by holders of American Express cards grew 9 percent during the April-June period, reflecting gains in the U.S. and abroad. That helped drive U.S. card services revenue up 6 percent to $4.5 billion, while international card services revenue rose 7 percent to $1.4 billion.

American Express cardholders tend to be more affluent than other credit card users, which is one reason the company has done well as the nation’s economy has gradually improved.