The Buffalo and Rochester areas had the state’s worst job markets in December, as Western New York lost more jobs from a year ago than any other part of the state, according to the latest federal numbers.

The latest government data show that the Buffalo-Niagara Falls metropolitan area lost 2,300 private-sector jobs, a decline of 0.5 percent, compared with last December. The region also saw a drop of 2,100 nonfarm jobs – which includes both private sector and government – which equates to a 0.4 percent decline.

The job count fell in both the goods-producing and service sectors, with fewer jobs in trade, information and financial activities. Only education and health services and leisure and hospitality saw gains.

But some experts are suspicious of the numbers. The federal Bureau of Labor Statistics took over responsibility for monthly employment estimates from the state in March 2011, and even slight changes in methodology could mean big swings in data in a market that doesn’t usually change much from month to month. Revised data will be released in March.

“I think the labor market is not as weak as the numbers are currently stating,” said John Slenker, regional economist for the state Labor Department. He projected that the local economy should be showing slightly positive changes, not negative. “I think we’re going to see a little more strength when the revisions come out.”

In particular, Slenker cited the decline of 2,400 jobs in professional and business services locally. That includes a gain of 1,500 jobs in professional, scientific and technical services – law and engineering firms, for example – but a drop of 4,000 jobs or 13.4 percent in administrative and support jobs.

That sector includes temporary staffing firms that normally see upticks coming out of a recession as companies prefer to use temporary labor initially before staffing up. A reversal in this area would also reverse the overall job decline in the local market.

In Rochester, private-sector jobs fell 2,200, or 0.5 percent, while nonfarm jobs declined 1,500, or 0.3 percent. Only Elmira had a worse decline compared to its overall size. The Southern Tier community lost 900 private sector and nonfarm jobs, but that represented declines of 2.8 percent and 2.3 percent, respectively.

Binghamton also lost 200 private-sector jobs, down 0.2 percent and 600 nonfarm jobs, down 0.5 percent, while Kingston in the Hudson Valley lost 200 private-sector jobs for a 0.4 percent loss and 400 nonfarm jobs, for a 0.6 percent loss.

By contrast, jobs grew the fastest over the past year in Glens Falls, at 3.6 percent; Ithaca, at 3.5 percent; and New York City, at 2.4 percent.

The picture in Buffalo and Rochester contrasted sharply with the rest of the state, where all other markets added both private-sector and nonfarm jobs. Overall, New York added 119,800 private-sector jobs since December 2011, up 1.6 percent, and 118,300 nonfarm jobs, up 1.3 percent. That includes gains of 92,700, or 1.9 percent, in the 10-county downstate region, and 6,100, or 0.2 percent, in the 52-county upstate area, with increases in both urban and rural areas.

The nation as a whole posted a 1.4 percent gain in nonfarm jobs, with 1.9 million, and a 1.7 percent gain in the private-sector, with 1.92 million new jobs.

Meanwhile, the entire state added 34,300 private-sector jobs from November to December, reaching an all-time high job count outside of government. The 0.5 percent seasonally adjusted statewide job gain for the month drove the total private-sector job count to an all-time high of 7,353,000. For the full year, the Labor Department said, the state economy added 123,200 jobs in the private sector.

As a result, the state’s unemployment rate fell to a seasonally adjusted 8.2 percent from 8.3 percent in November, as 786,800 New Yorkers were out of work, down from 793,600 in November. Geographically, the rate in New York City remained unchanged at 8.8 percent, while the rest of the state declined to 7.8 percent from 7.9 percent in November.

The U.S. unemployment rate for December was flat with November, at 7.8 percent, but was down significantly from 8.5 percent a year ago. The statewide rate was unchanged from a year ago, while New York City’s rate was down from 9.1 percent and the rest of the state was up from 7.5 percent.

“The New York State economy closed out the year with 34,300 private-sector jobs added in December and 123,200 added to the state’s economy in 2012,” said Bohdan M. Wynnyk, deputy director of the state Division of Research and Statistics. “In addition, the state’s unemployment rate continued its downward trend in December.”

Nationwide, the country added 155,000 nonfarm jobs – which includes both the private sector and the government – and 168,000 private-sector jobs, for gains of 0.1 percent and 0.2 percent, respectively, from November to December. The state added 35,100 nonfarm jobs, up 0.4 percent.