U.S. private sector activity rebounded in November after slowing the month prior, while new orders grew at their fastest pace since April 2012, according to an industry report released on Monday.

Financial data firm Markit said its preliminary composite Purchasing Managers Index (PMI) - a weighted average of its manufacturing and services indexes - rose to 57.1 in November from 49.6 last month.

This is the first month that Markit is publishing its composite and service sector data, which it has been compiling since October 2009. The reading for October 2013 was the lowest in the history of the data.

Readings above 50 signal expansions in activity.

On a composite basis, the new orders sub-index rose from 53.9 to 57.9, its best read since April 2012.

The PMI for the services sector, also reported by Markit on Monday, rose to 57.1 in November from 49.3 in October.

Last week, Markit's manufacturing sector PMI rose more than expected to 54.3, an eight-month high.

The sub-index for new business in the services sector rose to 58.5, a level last hit in March 2012, from 54.2 in October.

Despite the rebound in private sector activity, the pace of hiring for both the services sector and the total private sector slowed slightly in the latest month and companies have indicated uncertainty about their future prospects.

"Businesses have clearly rebounded strongly from any government shutdown worries, but companies report that they are concerned that the ongoing uncertainty regarding the debt ceiling has tempered their outlook for next year," said Chris Williamson, chief economist at Markit.

Markit's "flash" reading is based on replies from about 85 percent of the U.S. companies in the services sector that were surveyed. A final reading will be released on the first business day of the following month.