The U.S. economy grew at a slower pace in the third quarter than initially reported as businesses pared inventories, confirming the recovery's weakness but signaling future gains when companies replenish their stockrooms.

Gross domestic product, the total value of all goods and services produced in the U.S., grew at an annual rate of 2% in the July to September period, instead of an initially reported 2.5%, the Commerce Department said Tuesday. The revision was due largely...