WASHINGTON — U.S. productivity increased at a solid 4.6% pace in the July-September quarter, slightly below the initial estimate, while labor costs fell at a slower pace.

The third quarter increase in productivity was below the first estimate a month ago of a 4.9% increase, the Labor Department reported today. Productivity had surged at a 10.6% rate in the second quarter.

Labor costs fell at a 6.6% rate in the third quarter , a smaller drop than the 8.9% decline estimated a month ago.

Productivity, the amount of output per hour of work, is the major factor determining living standards. As productivity rises, employers can pay their workers more without having to boost the price of their products.