The preliminary report had pegged productivity at a gain of 1.9 percent over the second quarter.
Factory output was revised higher from 3 percent growth to 3.7 percent, after growing 2.6 percent in the second quarter.
In the quarter, the cost of wages and benefits rose 2.2 percent, slightly higher than reported in November. That put labor costs per unit at a decline of 0.1 percent July through September, unchanged from a month ago.
In the past four quarters, labor unit costs have fallen 1.1 percent, a typical pattern after a recession that creates a leaner workforce.