The number of positions waiting to be filled in the U.S. rose by 121,000 to 5 million in January, the highest level in 14 years, from a revised 4.88 million the prior month, the Labor Department reported today in Washington. The rate of hiring cooled, while the number of Americans quitting their jobs increased.

A steady rise in job listings is reinforcing signs of labor-market strength, as payroll advances have helped bring the unemployment rate down to its lowest level in almost seven years. At the same time, limited wage growth and lingering evidence of job-market slack have allowed Federal Reserve policy makers to be deliberate in considering their first interest-rate increase since 2006.

"The labor market is getting tighter and tighter," said Stan Shipley, an economist at Evercore ISI in New York, who projected 5.03 million openings. "You're seeing it in the unemployment rate going down and the job openings going up. It's harder and harder to find people qualified to fill positions."