WASHINGTON (AP) — U.S. companies advertised more jobs in April than in any month in six and a half years, a possible harbinger of strong hiring in the months ahead.

Employers posted nearly 4.5 million jobs, up strongly from 4.2 million in March, the Labor Department said Tuesday. It’s the largest number of job listings since September 2007.

Companies have been slow to fill openings since the recession ended, so the increase in postings won’t automatically lead to more jobs. The report showed that the number of jobs filled in April, 4.7 million, was largely unchanged from March. In the past year, job postings have jumped 16.5 percent, while hiring has risen just 6 percent.

But more job openings typically points to an improving job market. A separate monthly employment report on Friday showed the economy generated 217,000 jobs in May, while the unemployment rate remained at a fiveyear low of 6.3 percent.

“Today’s report appears to confirm that the U.S. labor market has indeed shifted to a period of stronger growth,” Jeremy Schwartz, an analyst at Credit Suisse, said in a note to clients.

Almost all the gain occurred in the private sector, while government job openings rose slightly. The biggest increases were in retail, restaurants and hotels, which include mostly lower-paying jobs. Still, the professional and business services category, which includes higher-paying jobs such as accountants and engineers, also posted a big jump.

There are now an average 2.2 unemployed people for each available job. That’s down from a peak of 6.7 in July 2009 just after the recession ended and close to the 2 to 1 ratio that is typical of a healthy economy.

Tuesday’s report, known as the Job Openings and Labor Turnover survey, offers a more complete picture of the job market. It reports figures for overall hiring, as well as the number of quits and layoffs. The monthly jobs figures are a net total of job gains or losses.

The additional data illustrates turnover in the job market. Stronger job markets usually include a greater amount of churn, with more people quitting and greater overall hiring.

In April, the number of people who quit or were laid off barely rose. More quitting can be a sign of confidence in the economy, since most workers quit only when they have another job or are confident they can get one. Quitting also opens up more jobs for the unemployed to seek.