WASHINGTON — Payrolls at US companies climbed in June by the most since November 2012, a sign the job market is strengthening as demand picks up.
The 281,000 increase in employment exceeded the most optimistic forecast in a Bloomberg survey and followed a 179,000 rise in May, data from the ADP Research Institute in Roseland, N.J., showed Wednesday. The median projection of 47 economists was 205,000.
The figure suggests the government’s jobs report, to be released Thursday, could also show a significant gain from May’s tally of 217,000 jobs. But the ADP numbers cover only private businesses and often diverge from the government’s more comprehensive report.
Those businesses are taking on more workers and limiting dismissals, bolstering economists’ projections that the economy will strengthen after a first-quarter contraction.
‘‘Job gains are broad-based across all industries and company sizes,’’ Mark Zandi, chief economist at Moody’s Analytics in West Chester, Pa., said in a statement. Moody’s produces the figures with ADP. ‘‘Judging from the job market, the economic recovery remains fully intact and is gaining momentum.’’
Manufacturers, builders, and other goods-producing industries increased their headcount by 51,000. Employment in construction rose by 36,000, while factories added 12,000 jobs, the report showed.
Payrolls at service providers climbed by 230,000.
Companies employing 500 or more workers added 49,000 jobs. Medium-sized businesses, with 50 to 499 employees, took on 115,000 workers, and small companies increased payrolls by 117,000, the most since February 2012.
Thursday’s data may also show overall payrolls, which include government agencies, rose by 215,000 workers in June after climbing by 217,000 the prior month, according to the survey of analysts. The unemployment rate probably held at an almost six-year low of 6.3 percent, the predictions show.
Federal Reserve policymakers are counting on an improving job market to help spur the economic expansion.
Industries from construction to autos to oil and gas are increasing jobs as growth accelerates after a first-quarter setback.
The economy contracted at a 2.9 percent annualized rate from January through March, the biggest drop-off since the same three months in 2009, the Commerce Department reported last month.
Consumer purchases grew at the weakest pace in five years.
Demand for automobiles remains a bright spot for spending. Cars and light trucks sold at a 16.9 million pace in June, the strongest since July 2006, after a 16.7 million rate in May, based on data from Ward’s Automotive Group. General Motors and Ford, the two largest US automakers, exceeded analysts’ estimates for deliveries last month.
The gross domestic product probably bounced back in the second quarter and will expand at an average 3.1 percent rate in the remaining two quarters of 2014, according to the median forecast in a Bloomberg survey conducted June 6 to June 11. Household purchases are also expected to improve, it showed.
Recent data corroborate that outlook. Factories, propelled by the strongest orders of the year, sustained gains in June and are poised to be part of the rebound, the Institute for Supply Management’s manufacturing report showed on Tuesday.