The US economy grew at a robust 3.9 percent pace in the third quarter, stronger than previously estimated as business investment and consumer spending picked up,  the Commerce Department said Tuesday.
Gross domestic product growth for July-September was revised from the initial estimate of a 3.5 percent annual rate, following 4.6 percent in the second quarter.
The number was unexpected; economists had predicted that the second official estimate for the quarter would be pared to 3.2 percent.
Contributing to the improved number was an upward revision to business inventory investment, especially in the wholesale trade and retail trade sectors.
Consumer spending, which accounts for about two-thirds of US GDP, was stronger than previously estimated, increasing 2.2 percent.