Financial data firm Markit said its composite Purchasing Managers Index (PMI) - a weighted average of its manufacturing and services indexes - rose to 56.2 last month from 49.6 in October. The "flash" or preliminary reading came in slightly higher at 57.1 last week.
A reading above 50 signals expansion in economic activity.
Last month's services sector PMI, also reported by Markit on Wednesday, rose to 55.9 from 49.3 in October.
Despite the rebound in private sector activity, the pace of growth in hiring for both the services sector and the total private sector slowed slightly in November. At 52.4 for both services and the composite, it was the lowest reading since March.
"Companies cited concerns about possible repeats of the government shutdown next year, and this uncertainty appears to have hit hiring," Chris Williamson, Chief Economist at Markit, said in a press release.
"The final PMI data on employment are weaker than the earlier flash estimate, and are running at a level consistent with private sector non-farm payroll growth of approximately 150,000. Given recent cuts to government payrolls, total non-farm payroll growth could have weakened to 140,000."
The key non-farm payrolls report for November is due Friday. A Reuters survey of economists shows an expectation for 180,000 jobs created last month.