PROVIDENCE, R.I. — Rhode Island’s treasurer has announced a new regional partnership dedicated to increasing gender, racial and ethnic diversity on corporate boards in the Northeast.

Treasurer Seth Magaziner said Wednesday that companies with stronger diversity at the senior level tend to outperform companies lacking diverse leaders.

The Northeast Investors’ Diversity Initiative includes the treasurers of Connecticut, Massachusetts, Maine and Vermont, the New York City comptroller and investors and asset managers in New York, Massachusetts and New Hampshire. Connecticut’s treasurer leads the coalition.

Magaziner says that with more than $283 billion in assets under management in total, the investor coalition intends to leverage their corporate relationships and shareholder rights to encourage boardroom diversity and inclusion.

Rhode Island’s policy is to vote against all director nominees sitting on boards with less than 30 percent diversity.