At the current rate of change, it could take women 47 years to reach parity with men as corporate officers of Fortune 500 companies, according to a study by Catalyst, an organization working to expand opportunities for women at work.

The study found that women held 15.6 percent of Fortune 500 corporate officer positions, down from 16.4 percent in 2005. The number of companies with three or more women corporate officers also decreased.

Women are still more than twice as likely to hold staff positions, whereas men hold roughly an equal percentage of line and staff positions. Line position experience is important for advancement to the highest levels, the organization notes.