Companies with high percentages of female directors significantly outperform those companies with few or no women directors, according to a report by advisory and research firm Catalyst.

“The Bottom Line: Corporate Performance and Women’s Representation on Boards,” which examined average returns between 2001 and 2004, found that the Fortune 500 companies with the highest numbers of female directors on the board outperformed those with the lowest by about 53 percent in average return on equity. Firms with a significant number of women board members also outperformed those with few to none on average return on sales by 42 percent, and average return on capital by 66 percent.

Additionally, having three or more female directors correlated with higher-than-average financial performance, the study shows. Companies with three or more women directors outperformed the average return on sales and return on equity by over 5 additional percentage points.

“Clearly, more is better,” Deborah M. Soon, Catalyst’s vice president of executive leadership initiatives, told Risk & Governance Weekly. “The flipside of the coin is just about all the companies with no women on their boards performed in the bottom quartile.”

This is the second “Bottom Line” report that Catalyst has released. The last study, published in 2004, focused on women in management positions. That study found that companies with the most women in top management teams performed, on average, 34 percent better than those with few to no women.