The Purchasing Managers Index for non-manufacturing businesses rose from 53.1 to 53.7, showing faster growth, as numbers above 50 indicate expansion, while below 50 indicates contraction.
The index for new orders among service-oriented businesses showed faster growth with the component index climbing from 54.5 in April to 56 in May.
The Employment Index, which tracks the number of employees, remained above 50 for the 10th consecutive month but only by a slim margin, as that index fell from 52 to 50.1.
The index for new export orders fell to break-even, sliding from 53.5 to 50.
Thirteen of 18 non-manufacturing industries showed growth while four showed declines.
Accommodation and food services notched the fastest gain, followed by transportation and warehousing; arts, entertainment and recreation; educational services; and management of companies and support services.
Declines were led by mining, with lesser contractions in healthcare and social assistance, real estate and agriculture, forestry, and fishing and hunting.