This study focuses on the dynamics of shared market-shaping intentions in business networks in the context of sustainability enhancement. Collective action between various market actors has been considered particularly important when the desired outcome of market shaping is enhanced sustainability (Keränen et al., 2023; Ottosson et al., 2020). Although successful collaborative market shaping is underpinned by shared intentions between the collaborative actors (Baker & Nenonen, 2020;  Maciel & Fischer, 2020), due to retrospective research methods it remains unclear how such shared intentions develop over time (Hawa et al., 2020). We study the development of shared intentions as a network management issue and turn to literature on strategic nets, where purposefully created inter-organisational networks, have been classified along a value-system continuum based on their goals and the determination of their underlying value-creating systems (Möller & Rajala, 2007). We employ a longitudinal real-time qualitative case study design to study a European cruise shipbuilding network in the midst of a sustainability transition. We focus on a business renewal net that has pursued sustainability enhancements to its products, processes, and ultimately markets via four consecutive publicly funded R&D projects starting in 2016 and continuing until 2025. Our results indicate that developing shared future-oriented market-shaping intentions in business networks is not a straightforward process when network collaborators face differing and sometimes conflicting interests and goals. Our analysis shows that the net’s intentions varied from cynicism towards shared goals to actively pursuing them as understanding of sustainability objectives evolved and as the consortium evolved with some partners leaving and new entering the net. Theoretically, we aim to contribute to the growing body of literature on market shaping by empirically examining collaborative market shaping from a network management perspective with particular attention to the dynamics of network actors’ market-shaping intentions. Managerially, our results will support the development of a collaborative market shaping strategy by highlighting the bottlenecks and pitfalls of shared intentionality.