By Jeanna Smialek, Bloomberg News

TEMPE, Ariz. (Sept. 9, 2014) — Gains in manufacturing boosted the U.S. expansion in August, led by a surge in orders for plastics and metals that powered the world’s largest economy past a global slowdown.

The Institute for Supply Management’s (ISM) index climbed unexpectedly to 59, the highest level since March 2011, from July’s 57.1, beating all forecasts in a Bloomberg survey of economists. The orders gauge was the strongest in a decade, the Tempe-based group reported Sept. 2.

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