us private sector economic growth maintained strong momentum in december as service sector activity expanded sharply on strong demand while supplychain delays in the manufacturing sector eased data from ihs markits survey of purchasing managers showed thursday the flash us composite output index fell to 569 in december from 572 in november a threemonth low the index is based on data from the firms pmi surveys for manufacturing and service sectors a reading above 50 indicates growth while a level below 50 signals contraction the index suggests a strong rise in private sector business activity although slower than rates seen earlier in the year the report said the survey data paint a picture of an economy showing encouraging resilience to rising virus infection rates and worries over the omicron variant said chris williamson chief business economist at ihs markit service sector business activity growth remained especially sharp while goods producers registered a slight uptick in the pace of expansion in production according to the report ihs markits flash us services business activity index declined to 575 in december from 580 in november below the 582 consensus forecast from economists polled by the wall street journal and a threemonth low service providers reported accelerating growth in new business while employment slowed as pressures on capacity remained substantial ihs markit said the ihs markit flash manufacturing pmi dropped to 578 in december from 583 in november missing economists estimates of a 586 reading and marking a oneyear low supplychain bottlenecks continued to hamper production though these eased to the lowest level since may as measures by suppliers delivery times the report said manufacturing output growth even picked up slightly amid a marked easing in the number of supply chain delays which also helped to take pressure off raw material prices mr williamson said inflationary pressures continued to mount for both manufacturing and services sector with firms facing increasing input prices however despite the increase in costs the pace of inflation of prices charged for goods and services softened for the second month running in december ihs markit said