WASHINGTON — U.S. employers posted a record-high number of open jobs for the second straight month as a rapidly rebounding economy generates intense demand for workers.

The number of available jobs on the last day of May rose slightly to 9.21 million, from 9.19 million in April, the Labor Department said today. That is the highest since records began in December 2000. The previously reported figure for April of 9.3 million was revised lower.

The number of people quitting their jobs slipped in May from a record high in April, but remains elevated. And the percentage of workers getting laid off hit a record low in May, the report said.

The figures point to a tight job market, with employers forced to pay more to attract workers yet still struggling to fill open jobs. And many workers are leaving jobs for better-paying positions at other companies. It’s unusual for such dynamics to have kicked in with the unemployment rate elevated at 5.9% in June, as the government reported last week.

But the lingering effects of COVID-19 are keeping many potential workers on the sidelines. Some of those out of work are worried about the risk of getting the disease from large crowds, while many older Americans have retired early. And an extra $300 in weekly unemployment aid has allowed Americans to seek out higher-paying jobs rather than return to previous positions that may have paid little.

Hiring picked up in June, the government said last week, as employers added 850,000 jobs, the largest monthly increase since last August. The unemployment rate ticked up to 5.9% from 5.8%, though that was partly because some people started looking for work that month.