WASHINGTON — The economy likely produced another solid month of hiring in January, a promising start for 2012.

Economists forecast that employers added a net 155,000 jobs last month and that the unemployment rate remained 8.5 percent for a second straight month, according to a survey by Factset.

The unemployment rate has fallen for four straight months. It’s at its lowest level in nearly three years.

A gain of 155,000 jobs would be down slightly from December, when employers added a net 200,000. Still, it would mark the seventh straight month in which at least 100,000 jobs have been added. That hasn’t happened since 2005.

On Friday, the government will also issue its annual revisions to earlier jobs figures. The revisions are expected to show that hiring was stronger over the past two years than previously thought. The government has said the economy added about 1.6 million jobs last year, nearly twice as many as in 2010.