WASHINGTON—A measure of U.S. services industry activity dropped to a one-year low in February and employment contracted, suggesting that a slowdown in economic growth at the end of 2021 persisted beyond the disruption from the winter wave of COVID-19 cases. The Institute for Supply Management said on Thursday its non-manufacturing activity index fell to 56.5 last month, the lowest reading since February 2021, from 59.9 in January. The third straight monthly decline in the index was despite coronavirus cases, driven by the Omicron variant, decreasing substantially from mid-January. A reading above 50 indicates growth in the services sector, which accounts for more than two-thirds of U.S. economic activity. Economists polled by Reuters had forecast the index rising to 61. The bulk of the survey was likely conducted before Russia started its war against Ukraine last week, which has boosted prices of oil, wheat, and other commodities. The economy hit a …