Circular economy development is about a system-level change towards significantly enhanced circularity and sustainability encompassing both biological and technical cycles. CE business models can be applied by companies to enhance the circularity of own operations as well as of the whole supply chain. In addition, they enable broad collaboration and partnerships at the system level. CE and associated approaches are also increasingly part of the sustainability reporting requirements within the EU. This study aimed at exploring, discovering, analysing and synthetizing the integration of circular economy business models into sustainability reporting by the three largest bioproduct companies in Finland. A qualitative research method was applied using the Annual Reports of the three companies as materials. The results suggest that all three companies report multiple approaches related to circular supply models, supply chains and inputs; and resource recovery. However, only a few approaches are reported related to product use/life extension, and no approaches were reported related to sharing and sharing platforms and product-as-a-service and product-service systems. All three companies have started reporting practices that take the EU operational environment into account.