JMI Equity has made an investment in SiriusDecisions Inc.

Wilton, Conn.-based SiriusDecisions is a subscription-based research and advisory services firm that focuses on sales and marketing best practices. Terms of the investment are not disclosed. The company’s founders will retain a majority stake.

Private equity firm JMI, headquartered in Baltimore, Md., invests in software and technology-services companies. The firm has more than $2.1 billion in committed capital under management. In February, the firm, in partnership with Investor Growth Capital, made a $31 million investment in WhiteHat Security.

Some of the firm’s other investments include AppNeta, a cloud-based network that provides performance-management services, BrightLine, which provides interactive TV marketing services, and, which provides interactive business marketing services.