WASHINGTON (MarketWatch) — Private-sector employment jumped a record 297,000 in December, according to Automatic Data Processing Inc.’s employment report released Wednesday, in what could be a signal that the recovery is finally adding jobs at a meaningful clip.

The jump was so large that even the company that produces the report on behalf of ADP, Macroeconomic Advisers, wrote in a note that the figure could be seen as “suspicious.” But they added that the report could still signal an improving employment environment.

“We accept that the [ADP report] is very likely overstating growth of private payrolls due to the seasonal” issues, according to Macroeconomic Advisers. “However, we would not be surprised to see a portion of the unexpected weakness in [the government’s employment data] in November reversed and manifested as outsized strength in December.”

Employment in the service-producing sector rose 270,000 in December, the largest monthly increase in the series that dates back to 2000, according to ADP. Employment in the goods-producing sector rose 27,000, the biggest increase since February 2006.

In December, employment gained 144,000 among medium-sized businesses, 117,000 among small businesses and 36,000 among large businesses, according to ADP.

The headline number stunned Wall Street, and Treasury prices TNX, -1.06% fell and the dollar DXY, -0.15% rose after the report’s release, while U.S. stocks SPX, +1.24% were stronger in late-day trade.

In November, private payrolls gained 92,000, ADP said.

“ ‘Sometimes numbers come as bolts from the blue; this is one of them.’ ” — Ian Shepherdson, High Frequency Economics

Upcoming payrolls report

On Friday, the government will report on December’s nonfarm payrolls, which also include government workers, with economists polled by MarketWatch looking for a gain of 143,000 and for the nation’s unemployment rate to remain at 9.8%. The economy has to add about 125,000 jobs a month to keep pace with population growth.

Given the strong ADP number, some analysts are now expecting a bigger move in the government report. The ADP report has frequently underestimated the government’s report.

“Sometimes numbers come as bolts from the blue; this is one of them. Nothing in any other indicators of the state of the labor market last month — jobless claims, help wanted, surveys — suggested anything like this was remotely likely,” said Ian Shepherdson, chief U.S. economist of High Frequency Economics, who said Friday’s report could now show 250,000 jobs added.

However, Zach Pandl, an economist at Nomura Securities International, cited the ADP report’s seasonal-adjustment distortions, and said that Nomura’s forecast for payrolls is unchanged.

“Companies often keep all employees on the payroll all year — even if they are not being paid — for tax purposes,” Pandl wrote. “The ADP report has historically had problems seasonally adjusting these December figures. In fact, all three of the largest ADP ‘surprises’ (reported growth relative to consensus forecasts) have occurred in Decembers.”

Other positive signs

There have been other recent pieces of good news for jobs. The Labor Department recently reported that the number of U.S. workers filing new applications for jobless benefits fell below a key level of 400,000. Economists say claims would have to remain below 400,000 before there’s a substantial gain in hiring. Read more about unemployment insurance.

Elsewhere Wednesday, outplacement consultancy firm Challenger Gray & Christmas Inc. reported that planned layoffs reached just over 32,000 in December, down 29% from the prior year, and the lowest monthly total since June 2000. And for 2010 as a whole, employers announced plans to cut about 530,000 jobs, the lowest since 1997, according to Challenger.

“The downsizing phase of the recession really came to an end in 2009,” said John Challenger, chief executive, in a statement. “Job cutting fell dramatically in the second half of that year. The pace of downsizing continued to slow in 2010 to levels we have not seen since before the 2001 recession.”

He added that the government sector “is likely to see heavy job cuts” in 2011 due to budget shortfalls.

“In fact, the sector could see an increase in job cuts in 2011 as state and local agencies, which saw the heaviest downsizing last year, are joined by federal agencies under increasing pressure from a Congress determined to cut spending,” Challenger said.