US companies hired the smallest number of employees in seven months in April while manufacturing growth slowed, providing more signs that the economy is encountering a soft patch.

Businesses added 119,000 employees to their payrolls last month, according to the latest ADP National Employment Report.

It fell short of economists' expectations for 150,000 jobs and was the smallest gain since last September.

The slowdown was primarily due to the effect of tighter fiscal policy through a combination of an increase in payroll taxes at the start of the year and the $85 billion government spending cuts that went into effect across the board in March, said Mark Zandi, chief economist at Moody's Analytics, which jointly develops the ADP report.

"They are starting to bite and starting to weaken growth," said Zandi. "It's affecting all industries and almost all company sizes."

March's private payrolls were revised down to an increase of 131,000 from the previously reported 158,000.

Two separate reports on the manufacturing sector also showed employment slowed in April, and analysts said there was some risk Friday's larger employment report from the US government could disappoint.

After reaccelerating in the first quarter, recent data suggests overall economic growth cooled heading into the second quarter, a familiar pattern the recovery has seen in past years.

"This slowing pace of growth we have been seeing the past three years seems to be taking hold again," said Sam Bullard, senior economist at Wells Fargo in Charlotte, North Carolina.

That is widely expected to keep the Federal Reserve on course as it tries to support the economic recovery through its monthly bond purchases of $85 billion.

The Fed convened for the last day of its two-day policy-setting meeting today and is due to issue a statement around 6pm Irish time.

Other reports today showed growth in the manufacturing sector slowed last month, while construction spending dropped to a seven-month low in March.

Financial data firm Markit said its final US Manufacturing Purchasing Managers Index (PMI) slipped to 52.1 from 54.6 in March. It was the lowest final reading since October.

That was echoed by a separate report from the Institute for Supply Management (ISM) that showed the sector expanded only modestly with its index coming in at 50.7, down from 51.3.

A reading above 50 indicates expansion for both.

Construction spending fell 1.7% to an annual rate of $856.72 billion, the lowest level since August, according to the Commerce Department.

The drop could cause the first-quarter economic growth estimate to be trimmed from its first reading of 2.5%.

Focus will turn to Friday's jobs report from the Labour Department, which is expected to show overall nonfarm payrolls increased by 145,000, an improvement over the paltry 88,000 seen in March.

Economists sometimes tweak their payrolls forecasts following the ADP report, though the private sector report does not always accurately predict the government figures.

"This put a downward bias on expectations on Friday's payroll number," Bullard said of the ADP report.

Since ADP overhauled its employment report late last year, it has missed the government figures by an average of 40,000 a month in either direction, according to Jim O'Sullivan, chief US economist at High Frequency Economics.

That is better than the 58,000 average miss in the 12 months before that, but with only six months' worth of the new ADP report, the history is not yet conclusive, said O'Sullivan.