WASHINGTON — Consumer borrowing posted the smallest increase in six months in April as Americans actually paid off some of their credit-card debt.

The Federal Reserve reported yesterday that consumer borrowing rose at an annual rate of just 1.3 percent in April, down from a 7 percent rise in March. It was the weakest showing since consumer debt rose at a tiny 0.1 percent rate last October.

The slowdown was led by a 0.5 percent rate of decline in the category of debt that includes credit cards.

That meant in April consumers were paying off more credit-card debt than they incurred, something that has not occurred in 13 months.

The increase of $2.6 billion in total debt was far below the $6 billion increase that had been expected. Economists were looking for some slowdown given that debt rose by $14 billion in March, the biggest increase in four months.

The category of credit that includes auto loans posted a 2.3 percent rate of increase in April, down from a 5.7 percent rate of gain in March.

The overall economy slowed to an anemic increase of just 0.6 percent in the first three months of this year, the weakest showing in more than four years.

Analysts believe that growth will rebound in the current quarter to a more respectable 2.5 percent to 3 percent rate.