The pace of growth in the U.S. services sector accelerated in August to its fastest pace in nearly eight years as sales and orders grew and employers hired more, an industry report said Thursday. The Institute for Supply Management (ISM) said its service-sector index rose to 58.6 last month from 56.0 in July. It was the highest point since December 2005 and easily surpassed economist expectations. Any reading above 50 signifies expansion in the massive U.S. service sector, while a reading below 50 indicates contraction. The index's measure of hiring rose sharply from 53.2 to 57.0, the highest in six months and an encouraging sign for the labor market because the service sector employs 90 percent of the U.S. workforce, including retail, construction, healthcare, leisure, and financial services. The new-orders and business-activity components hit their highest levels since February 2011. New orders rose to 60.5 from 57.7 in July, and business activity rose to 62.2 in August from 60.4 the previous month.