A coalition of institutional investors, nonprofits, and others advocating for more diverse corporate boards is kicking off a matchmaking initiative to help add women of color to their ranks.

The Thirty Percent Coalition, which wants women to hold at least 30 percent of board seats at public companies in the U.S., is focusing its attention on companies in the S&P 1500 index. Women currently represent 23 percent of S&P 1500 directors, but only 3.5 percent of these women are African American, Asian, Hispanic, and Native American, according to data from Institutional Shareholder Services Inc.

To help companies recruit new board members, the coalition has sent letters inviting corporate executives to events across the U.S. that will serve as mixers for getting to know potential directors. The candidates will be drawn from organizations that are coalition members, such as the Latino Corporate Directors Association and Ascend, which represents Asian directors.

The campaign builds on an ongoing push for greater gender diversity on corporate boards by making the business case for including women of color. African American, Asian, and Hispanic women are on track to make up a majority of all women in the U.S. in coming decades, Census data show. So companies without a woman of color on their board are overlooking a major part of the nation’s population and buying power, the coalition says.

“They’re not getting to the table,” said Charlotte Laurent-Ottomane, the coalition’s executive director.

Research indicates minority women that get directorships may also be stretched thinner than their peers, since they tend to sit on more than one board at a time as companies turn to existing candidates rather than bringing in new ones.

“It is important to encourage more women, and particularly women of color, to pursue senior leadership positions, including a seat at the boardroom table,” Intel Corp.'s Chief Diversity and Inclusion Officer Barbara Whye said in a statement. Whye is also a member of the Thirty Percent Coalition’s board.

Nearly 200 companies with all-male boards have added women amid advocacy from the coalition since 2012. The coalition’s members, which represent more than $5 trillion in assets, include large pension funds in California and New York, along with investment firms, such as Pax World Funds and Walden Asset Management.

The coalition’s latest campaign is funded by a grant from the Nathan Cummings Foundation.