Major companies like Coty,??????? ???????? ??? ??????? Kia and Nintendo have been singled out for their lack of gender diversity in a new report detailing the boardrooms of some of the world's most high-profile corporations.

LedBetter, a research group backed by the International Women's Media Foundation, released its first report on Tuesday, showing that many companies have few or no women in top leadership positions. 

H&M Group, Gap Inc., and Best Buy are among the companies with the greatest gender diversity in leadership roles.

Overall, the study found a drastic shortage of women at the top of companies: Only 6% of the companies in the LedBetter database have a woman as CEO. 

"LedBetter’s mission is to make public which companies score well when it comes to gender equality in leadership, and which ones don’t. So often we buy products without knowing who’s behind them and how they align with our personal values. With LedBetter, that information is just one click away," said LedBetter co-founder and CEO Iris Kuo in a press release announcing the launch of the group's website.

The LedBetter report provides one of the clearest indications yet of the continuing gender gap in the leadership of major companies. The issue has received greater attention in recent years, but the data released Tuesday highlights that there is still a long way to go before women are evenly represented in the high levels of corporate power.

There have been efforts to encourage greater gender diversity in corporate leadership, but they can face opposition from board members, or from shareholders themselves. Restaurant Brands International (RBI), parent company of Tim Hortons, Burger King and others, has rejected a proposal to put a formal diversity policy in place. Discovery Communications has also been the recipient of criticism for maintaining its entirely male board of directors. In May, a proposal to put in place a system to foster diversity on the Discovery board was rejected by a margin of over 4 to 1, according to the Washington Post.

Professor Siri Terjesen of American University told Mashablethat the all male board is an increasingly rare structure. "Frankly RBI’s lack of diversity is particularly surprising given that the firm [has] a lot of services, and firms in the service industry have more women on their boards generally as compared to manufacturing firms."

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Despite the resistance to adding female board members, recent research touts the benefits of having them. A report by CATALYST shows that Fortune 500 companies with women board directors had greater financial success, on average, than those without. It also showed stronger performance at companies with three or more female board members. 

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