Updated

U.S. service firms' activity expanded in December by the most in nearly a year, driven by a jump in new orders and hiring.

The Institute for Supply Management says its index of non-manufacturing activity rose to 56.1 in December from 54.7 in November. That's the highest level since February and above the 12-month average of 54.7. Any reading above 50 indicates expansion.

The report measures growth in industries that cover 90 percent of the work force, including retail, construction, health care and financial services.

An index of employment rose strongly. That conflicted with a Labor Department report Friday that said the economy added just 109,000 service jobs last month, the fewest since June. For all of 2012, the economy added 1.69 million service jobs.