The number of new jobs posted online in June was unchanged from May, marking the fourth straight month of year-over-year declines, the Conference Board reported this week.

Some 3.8 million job openings were advertised online last month, or about 2.5 vacancies for every 100 persons in the labor force, according to data compiled from 1,200 Web-based job boards. That's down from 2.9 vacancies per 100 persons in May, and 11.2 percent below a year ago, the report said.

"Spring is typically a time of seasonal increases in labor demand, but not this year," Gad Levanon, the research group's senior economist, said in a statement. He said employment declines had likely not reached bottom.

Employers in Alaska, Colorado and Nevada posted the most new jobs online last month, while Wyoming posted the least. Employment in healthcare and management continued to lead demand.