Cross-sectoral strategic negotiation is a key challenge in PPPs. Based on framing and game theory, we investigate the effect of sectoral agency, affect, and bargaining domain on sectoral agents’ bargaining behaviour in a PPP renegotiation scenario. Results confirm that public agents are more likely to bargain for satisfactory, ‘good enough’ contracts than private agents, who maximize their utility. This difference is stronger in the loss vis-a-vis the gain domain. These experimental findings advance our understanding of psychological mechanisms underlying cross-sectoral negotiations, suggesting that public managers and policy-makers account for partners’ dissimilar bargaining logics to prevent asymmetric loss socialization in PPPs.