WASHINGTON — U.S. employers advertised more job openings in January, suggesting that hiring will remain healthy in coming months.

Job openings rose 2.2 percent in January from December to 3.69 million, the Labor Department said Tuesday. Openings had fallen nearly 5 percent in December, and they remain below November's level of nearly 3.8 million.

Yet the report provided further evidence the U.S. job market is strengthening. Employers laid off the fewest workers in January than in any month since records began in 2001. And the number of Americans who quit their jobs rose to the highest in more than four years.

The biggest increase in job openings was in professional and business services, which includes high-paying fields such as accounting, engineering, and architecture. It also includes temp jobs, which typically carry few benefits.

On Friday, the government reported that hiring in February was robust: Employers added 236,000 jobs, and the unemployment rate fell from 7.9 percent in January to a four-year low of 7.7 percent.