U.S. Service Sector Grows Slower Than Expected in December

The U.S. service sector continued expanding in December, though at a slightly slower rate than the prior month, a key index showed Wednesday. The Institute for Supply Management said its non-manufacturing index stood at 55.3 in December, slightly down from November's reading of 55.9. A reading above 50 indicates overall expansion in service-sector activity. Economists surveyed by The Wall Street Journal expected the index to hit 56.3 in December. Write to Josh Mitchell at joshua.mitchell@wsj.com