WASHINGTON — Americans increased their borrowing in April at the slowest pace in seven months, marked by a big slowdown in the category that covers auto and student loans.

Consumer debt rose $9.3 billion in April after a gain of $12.3 billion in March, the Federal Reserve reported Thursday. It was the smallest monthly increase since a rise of $8.6 billion in September.

The category that includes credit cards climbed $2.3 billion in April after falling by $1.1 billion in March. But the category that includes auto loans and student loans rose $7 billion in April, about half of the $13.4 billion March increase.

Consumer borrowing trends are closely monitored for clues they can provide about the willingness of consumers to borrow more to support their spending. Consumer spending accounts for 70 percent of economic activity.

The overall economy, as measured by the gross domestic product, grew at a modest annual rate of 2.2 percent in the January-March quarter. But economists are forecasting a sizable rebound in the current April-June quarter based on reports that consumer spending has picked up again after a winter slowdown.

Even the modest gain in consumer credit in April was enough to push borrowing to a fresh record of $3.88 trillion on a seasonally adjusted basis. The monthly borrowing report does not include mortgages or any other debt secured by real estate