The department's Job Openings and Labor Turnover survey, or JOLTS report, found that businesses and government advertised 2.4 million open positions on the last day in July, down from 2.5 million in June. That's also the fewest openings since the department began compiling the data in December 2000.
Still, jobs are being added in some sectors, as companies seek more health care, technology and child care workers.
The report underscores the tough competition that jobless Americans face. With 14.5 million unemployed people in July and only 2.4 million openings, that means there were six unemployed people, on average, for every job opening.
The report also adds to evidence that companies likely will wait until the economy is clearly recovering before hiring new employees. Many analysts believe the economy is likely to grow at a healthy 3 percent rate in the second half of this year, pulling the country out of the worst recession since the 1930s.
But they also worry that the growth will be difficult to sustain, particularly once government stimulus measures, such as the Cash for Clunkers program that ended last month, are no longer in effect.
To be sure, there are some signs that hiring is slowly resuming. About one-third of both manufacturing and service sector companies plan to add jobs in September, according to a survey by the Society for Human Resource Management. That's the highest combined total for the two sectors since October 2008, the group said.
And online job postings increased by 5 percent in August from July, according to the Conference Board, a business research group. Job listings rose by 169,000 to 3.5 million, the board said, though that is down from 4.6 million a year earlier.
The largest increase in job openings was in health care practitioners and technicians, the Conference Board said, which rose by 52,700 to 574,400. That category includes physical and occupational therapists and registered nurses.
Management jobs rose 18,900 to more than 431,000, while computer and mathematical sciences increased by 8,800 to 406,800, according to the Conference Board's report.
The online job search Web site SimplyHired.com also has a large number of postings for physical therapists, according to its chief executive, Gautam Godhwani. That occupation was the Web site's "least competitive" in July, Godhwani said, meaning that it had the highest ratio of openings to job seekers.
That's likely a reflection of the aging of the population and the fact that baby boomers are more likely to remain active as they age, compared with previous generations, Godhwani said.
Meanwhile, Bright Horizons Family Solutions, which provides child care in 550 centers nationwide, has 425 openings, according to spokeswoman Bridget Perry. The jobs are mostly teaching positions in the child care centers and require experience in early childhood education, she said.
According to the Labor Department's monthly employment report released last week, child care providers added 11,100 jobs in August.
Some technology companies also are adding new workers, despite the slowdown. IBM Corp. is hiring or retraining up to 4,000 people to work on data analysis projects, according to spokeswoman Laurie Friedman. The company hopes to profit from what it calls "analytics" as more businesses, nonprofits and government agencies seek to use reams of data they have collected to spot and analyze trends.
For example, the Arkansas state government is using IBM technology to track the use of federal stimulus funding to improve school programs, the company said. IBM also is helping the New York City police and fire departments use their data to anticipate fires and crime.
"More and more organizations have mountains of data that is valuable for making decisions," said Jim Spohrer, IBM's director of global university programs. Spohrer's group is working with colleges and universities worldwide to encourage more training in analytics.
Brocade Communications Systems, a data storage and networking company based in San Jose, Calif., also is adding new jobs as its revenue grows. The company plans to hire about 130 college graduates this year, up about 75 percent from the previous year, spokeswoman Michelle Lindeman said. The new hires are in engineering, sales, marketing and other fields.
"We think it's really a competitive advantage for us when a lot of other companies aren't hiring," Lindeman said. "We're able to snatch up the best and the brightest."