WASHINGTON — U.S. employers posted fewer jobs in July than in June, further evidence that hiring may stay weak in the coming months.

Job openings fell to a seasonally adjusted 3.67 million, the Labor Department said Tuesday. That’s down from June’s 3.72 million job openings, which was revised lower.

The data follow Friday’s disappointing employment report, which said the economy added only 96,000 jobs in August. That’s below July’s total of 141,000 and the average 226,000 a month added in the first three months of the year. The unemployment rate fell to 8.1 percent from 8.3 percent, but only because the number of people working or looking for work fell.

The drop in available positions has made job hunting more competitive. Nearly 12.8 million people were unemployed in July, meaning 3.5 people were competing for each open position.

While that’s down from a post-recession high of 7 to 1 in July 2009, in a healthy economy the ratio is usually 2 to 1.

Job openings have increased 68 percent from 2.2 million over the past three years. But companies aren’t filling them quickly. Total hiring has increased only 11 percent in that stretch.

There are several reasons companies aren’t hiring faster. Companies may not be offering sufficient pay to entice workers to take the jobs. Some employers say they can’t find enough skilled workers in certain industries, such as information technology.

The report also highlights one reason the job market remains weak. Layoffs have fallen steadily recently, but companies aren’t stepping up hiring.

Overall, employers hired 4.2 million people in July, down from almost 4.3 million in the previous month. Before the recession, total hires routinely topped 5 million.