Matthew Kiernan, a longtime advocate of sustainable investing, is leaving RiskMetrics Group less than eight months after the firm bought Innovest, the firm he co-founded and co-led, reports Responsible Investor.

A spokesperson for RiskMetrics confirmed Kiernan would be leaving shortly to pursue personal interests, Responsible Investor reports. previously reported that RiskMetrics is set to buy Boston-based KLD Research & Analytics, another firm that has focused on socially responsible and sustainable investing research.

Kiernan, author of Investing In A Sustainable World and co-head of the Sustainability Solutions Group at RiskMetrics, is set to participate in the panel Why The Smart Money Is Going Green at the upcoming SRI in the Rockies conference next week.