WASHINGTON (Reuters) – U.S. labor costs increased solidly in the third quarter, but private sector wage growth slowed considerably, suggesting inflation had either peaked or was close doing so. The Employment Cost Index, the broadest measure of labor costs, rose 1.2% last quarter after increasing 1.3% in the April-June period, the Labor Department said on Friday. Economists polled by Reuters had forecast the ECI rising 1.2%. Labor costs increased 5.0% on a year-on-year basis after advancing 5.1% in the second quarter. The ECI is widely viewed by policymakers and economists as one of the better…