The U.S. manufacturing sector expanded for the 34th consecutive month in May, a leading industry survey showed on Friday.

The U.S. Institute of Supply Management (ISM) manufacturing index, also known as the purchasing managers index (PMI), stood at 53.5 percent in May. It was a modest decrease from April's reading of 54.8, indicating a decelerated monthly growth.

A reading above 50 percent indicates that the manufacturing sector is generally expanding.

Of the 18 U.S. manufacturing industries, 13 reported growth last month, including furniture and related products, electrical equipment and machinery, said the ISM. Four industries, including food and transportation equipment, reported contraction.

Factories have been an important source of hiring and growth since the recession ended in the summer of 2009. Some manufacturers last month reported steady business, while some others said business was lower than expected.

The overall U.S. economic growth was slower than previously estimated. The Commerce Department on Thursday lowered its estimate for first-quarter growth from 2.2 percent to 1.9 percent.

The latest employment report from the Labor Department showed that the jobless rate rose to 8.2 percent in May.