The ADP National Employment report showed U.S. private employment rose by 145,000 jobs last month, compared with economists' projections of an increase of 200,000 jobs, adding to recent signs of a cooling labor market.
With growing concerns about a worsening economic outlook following the recent turmoil in the banking sector, market expectations have shifted in favor of the U.S. central bank hitting the brakes on its interest rate hikes.
"But at the same time, I think investors are closely watching to make sure that we don't fall into a deep recession."
Traders' bets of a pause by the Fed in May shot up to 62.2%, while odds of a 25-basis point interest rate hike fell to 37.8%, according to CME Group's Fedwatch tool.
All eyes are now on the non-farm payrolls data for March, a more comprehensive employment report, that is due on Friday for more conclusive clues on the state of the labor market.