This thesis addresses the potential of private-public partnerships (PPPs) to involve private forest owners in formal forest protection. These partnerships have been widely advocated as means to engage actors from diverse sectors in collaborative new relationships, formed in a step-wise manner, to improve management of resources that combine public and private goods. Nature Conservation Agreements (NCAs) are the first kind of PPPs to be used in Swedish forest protection. NCAs were introduced in 1993 and are agreements based in civil law between a private forest owner and the Swedish Forest Agency or County Administrative Board. Although NCAs were introduced to promote interest in nature conservation among forest owners, the response has been rather weak. Thus, in 2010 the government launched a pilot project called the Komet program, in which private forest owners in selected pilot areas initiated protective measures. Although criticized by environmental non-governmental organizations, the government decided after the pilot project terminated in 2014 to implement the Komet program’s working methods nationwide. In this thesis, PPPs’ potential to contribute to forest protection is analyzed by applying the “Ladder of Partnership Activity” framework, developed to study global PPPs, with appropriate modifications for a national context. The framework incorporates, in a stepwise manner, context, the actors’ motives relating to trust-building, the creation of collaborative advantages in the partnering process and the institutionalization of PPPs. The thesis contributes to an empirical understanding of top-down and bottom-up PPP processes. It is based on studies in which qualitative research methods were applied to examine selected cases presented in four papers, designated Papers I-IV. The main sources of information are qualitative interviews with involved forest actors and policy documents they have produced. Papers I and II focus particularly on trust-building and the partnering process as perceived by involved forest actors, while Papers III and IV address the institutionalization of PPPs and their requirements to change the political order of forest protection in accordance with governmental objectives. The results show that willingness to adopt PPPs is dependent on past experience of collaborative efforts. They also show there is substantial discretion in involved actors’ interpretation of prescribed guidelines, and their motives may vary substantially. However, as long as they share the same ultimate objective, i.e. to protect forests, PPPs may still be successfully established. A major potential problem is that public officials tend to prioritize protection of biodiversity, while forest owners want to protect social values and unproductive (“useless”) forests. Thus, shared motives are essential to establish trust and initiate collaborative efforts. The voluntary element of initiatives supported by the Komet program appears to be essential for deliberation. PPPs need to be implemented nationwide to be institutionalized. However, the Swedish government has not provided sufficient resources and leadership capacity to enable PPPs to play their envisaged role in its forest governance system. If the government wants to adopt bottom-up approaches, it needs to provide sufficient resources so that the partnerships does not compete with other formal instruments and protection arrangements. Furthermore, coordination within and between sectors needs to be improved to clarify the purpose of the policy recommendations.