A new study finds modest progress towards increased gender diversity in corporate boardrooms around the world.

In the wake of the adoption of new rules by several securities regulators in Canada designed to help encourage increased gender diversity, new research from Thomson Reuters, reports a gradual increase in the percentage of companies that have women on their boards. On a global basis, it found that 64% of companies now report having female board members, up from 56% in 2009.

The study also notes that only 20% of companies have a board consisting of at least 20% women, up from 13% in 2008. And, just over half of companies (51%) now report boards comprised of at least 10% women, up from 40% in 2008.

Europe leads the way in gender diversity, the study found, followed by the Americas, with the Asia Pacific region continuing to report having the least diverse boards. By sector, healthcare, financial services and consumer goods & services companies have the most gender-diverse boards, the study found; while, the energy sector has the least diversity.

The study also observed an increase in the adoption of policies and processes regarding gender diversity and equal opportunity. Companies in Asia have shown the greatest increase in the implementation of these policies over the last five years, it says, but they remain well below the levels reported in other regions.

Finally, the research also continues to observe a correlation with improved stock market performance for firms with diverse boards. It says that indices made up of companies with mixed boards outperform their benchmark index; whereas indices comprised of firms with no women on their boards had slightly higher tracking errors, “indicating potentially more volatile portfolios and on average underperformed relative to mixed boards.”

“Clearly our data shows that there are advantages of having more women on corporate boards,” says André Chanavat, product manager, Environmental, Social & Governance (ESG) at Thomson Reuters. “Although progress towards gender diversity on corporate boards is slow, it is indeed moving in the right direction to a global advantage that allows for increased transparency, performance and overall effectiveness.”

The report analyzes the level of gender diversity on corporate boards compiled from 4,255 public companies globally.