NEW YORK, April 2 (Reuters) - U.S. stocks edged lower at the open on Monday after recording their best quarter since 2009 as investors awaited data on U.S. manufacturing for signs of improvement in the pace of growth.

The Dow Jones industrial average dropped 27.02 points, or 0.20 percent, to 13,185.02. The Standard & Poor's 500 Index fell 1.66 points, or 0.12 percent, to 1,406.81. The Nasdaq Composite Index lost 6.99 points, or 0.23 percent, to 3,084.58.

The Institute for Supply Management's March manufacturing index is due at 10 a.m. EDT (1400 GMT).