WASHINGTON — U.S. employers hired the most people on record in April, while the number of open jobs was largely unchanged, evidence that the job market remains solid.

The Labor Department said Monday that businesses filled 5.9 million jobs that month, 4.2% more than in March and the most since records began in December 2000.

Some of the increase in hiring simply reflects population growth. As a percentage of the workforce, new hires reached 3.9%, a strong reading but below the record of 4.3% reached in January 2001.

The report shows employers are confident enough about the economy to add staff. Still, there were warning signs: The number of job openings has declined from a record 7.6 million in November to 7.4 million in April. That suggests demand for labor is softening a bit.