U.S. non-manufacturing sector expanded for the 40th straight month in April, but its growth pace slowed, a widely recognized U.S. private survey revealed on Friday. The Non-Manufacturing Index (NMI), which measures activity in the U.S. service sector, decreased to 53.1 percent last month from 54.4 percent in March, the Institute for Supply Management (ISM) said in its monthly survey. The NMI survey covers all sectors outside of manufacturing. A reading above 50 indicates expansion of the service sector. The index showed that new orders, a signal of future business, decreased last month to 54.5 from 54.6 in March, while the survey\'s employment component dipped to 52.0 in April from 53.3 in March, said the ISM. A total number of 14 industries reported growth last month including construction and retail trade, while four other industries including mining reported contraction. The NMI index is closely watched because the service sector absorbs about 90 percent the U.S. workforce, and is a key indicator for the overall health of the economic recovery.