21 Invest, a private equity firm that offers funds and portfolio management services, completed the acquisition of Energreen, a producer of self-propelled and remote-controlled robotic machines for green maintenance. Financial terms were not disclosed. "Energreen is an Italian company that already boasts a leadership position at the international level. The ability to innovate with a strong focus on environmental sustainability is a fundamental starting point for 21 Invest to support Energreen in becoming a worldwide leader in its industry," Alessandro Benetton, 21 Invest Founding Managing Partner.