EQT, via its EQT Mid Market Europe fund, has signed a definitive agreement to sell Ontinue, an AI-powered managed cybersecurity services provider, to Quorum Cyber. Ontinue helps organizations detect, investigate and respond to cyber threats across Microsoft environments, serving more than 250 customers across Europe and the US through a 24/7 delivery model. Its proprietary ION platform uses agentic AI automation to increase the speed, efficiency and accuracy of threat detection and response.

Ontinue was originally developed within Open Systems as its managed detection and response business before being carved out as a standalone company in 2023, as its technology, organization and strategic priorities became increasingly distinct. EQT initially invested in Open Systems in 2017 and supported its transformation from a network-focused managed security services provider into a secure access service edge business; Open Systems nearly doubled sales and more than tripled EBITDA during EQT's ownership before being sold to Swiss Post in 2024.

Since Ontinue became a standalone company, EQT has helped it build out its leadership team and go-to-market organization internationally, while consolidating three technology platforms into a single AI-native, automation-first platform. The company also completed three add-on acquisitions focused on data science, AI and cybersecurity services during EQT's ownership.