NEW YORK — Small business hiring slowed in March, a sign that company owners are holding on to their cautious approach to expanding their staffs.

That’s the finding of payroll provider ADP, which counted 47,000 new jobs at its small business customers. The companies had added 66,000 customers in February and 64,000 in January.

Small business hiring has ebbed and flowed in recent years, picking up momentum for several months at a time and then slowing. Owners have said in recent surveys they won’t take on more employees unless their revenue justifies the expense and risk. But many also report they’re having a hard time finding candidates to fill their open positions; that’s another likely factor in last month’s tally.

But hiring by companies of all sizes last month was strong — ADP counted 241,000 new jobs at all its business customers.

Surveys taken by banks and small business groups don’t show a consensus about owners’ plans to hire in the next 12 months. In some surveys, a third of owners say they expect to hire, but in others, only about 20 percent expect to expand their staffs.