WASHINGTON (AP) — U.S. employers added 157,000 jobs in January, and hiring was stronger at the end of last year than previously thought, providing reassurance that the job market held steady even as economic growth sputtered.

The Labor Department report today showed a jump in hiring just when the economy faced the threat of deep spending cuts and tax increases from the fiscal cliff. Job gains in November were revised to 247,000 from 161,000 and in December to 196,000 from 151,000.

The mostly upbeat report included one negative sign: The unemployment rate rose to 7.9 percent from 7.8 percent in December.

The rate is calculated from a survey of households, and more people in that survey said they were unemployed. The job gains are derived from a separate survey of employers.

The hiring picture over the past two years also looked better after the department’s annual revisions. The revisions showed that employers added an average of roughly 180,000 jobs a month in 2012 and 2011, up from previous estimates of about 150,000.

One notable change in the job market is the stronger contribution from construction companies. They added 28,000 jobs in January and nearly 100,000 in the past four months. The gains are consistent with a rebound in home construction and a broader recovery in housing.

Retailers added 33,000 positions in January and health care gained 23,000 jobs. Manufacturers posted a small increase of 4,000. Restaurants and hotels added 17,000.

Average hourly wages rose 4 cents to $23.78, the department said, and have increased 2.1 percent in the past 12 months. That’s slightly above the inflation rate, which was 1.7 percent.

Last month’s hiring should cushion the impact of the higher Social Security taxes that most consumers are paying this year. And it would help the economy resume growing after it shrank at an annual rate of 0.1 percent in the October- December quarter.

Higher Social Security taxes are reducing take-home pay for most Americans. A person earning $50,000 a year will have about $1,000 less to spend in 2013. A household with two high-paid workers will have up to $4,500 less. Taxes roseaftera2percentcut,inplacefortwo years, expired Jan. 1.