THE United States work force was more productive in the summer than originally thought, reflecting the fact that the US economy produced more goods and services than first estimated.

Despite the revision, the efficiency of US workers is increasing at a much slower pace than last year, and economists say that could signal more hiring in the near future.

Productivity grew at an annual rate of 2.3 percent in the July-September quarter, an improvement over an initial estimate of 1.9 percent productivity growth, the US Labor Department said yesterday. Labor costs fell at an annual rate of 0.1 percent, unchanged from the initial estimate made a month ago.

Productivity measures the amount of output per hour of work. The upward revision follows a higher second estimate for economic growth in the third quarter of 2.5 percent. When the economy produces more goods and services with essentially the same work force, productivity rises.

In 2009, productivity rose 3.5 percent, the biggest advance in six years. Since the start of this year, productivity has averaged a much slower 1.5 percent growth rate.

Economists see the slowdown as an encouraging sign that companies will have to hire more laid-off workers. A rebound in hiring would provide a welcome boost when unemployment is at 9.6 percent.