U.S. consumer credit decreased at an annual rate of 4.6 percent in August, the largest monthly drop in 16 months, which indicates a struggling economic recovery, according to the Federal Reserve Friday.

Total borrowing in August dropped to 2444.9 billion U.S. dollars from the revised figure of 2454.4 billion dollars in July.

The U.S. central bank said demand for revolving credit, the category that includes credit cards, dropped 3.4 percent in August to 790.1 billion dollars after declining 5.4 percent in June.

In August, the borrowing in the non-revolving category which includes auto loans dropped at an annual rate of 5.2 percent to 1654.8 billion dollars.

Consumer spending, which accounts for about 70 percent of the overall economic activity, remains the major drive of the U.S. economy.