Post-merger integration (PMI) planning presents significant challenges due to the complex interdependencies between integration initiatives and their associated synergies. While dependency-based planning approaches offer valuable frameworks, practitioners often become anchored to specific integration paths without systematically exploring alternative solutions. This research introduces a novel AI-assisted tool designed to expand and enhance the exploration of viable integration planning options. The proposed system leverages a frontier model-based agent augmented with specialized reasoning techniques to map and analyze dependencies between integration plan elements. Through a chain-of-thought planning approach, the tool guides users in systematically exploring the integration planning space, helping identify and evaluate alternative paths that might otherwise remain unconsidered. In an initial evaluation using a simulated case study, participants using the tool identified 43% more viable integration planning options compared to the control group. While the quality of generated options showed improvement, the effect size was modest. These preliminary results suggest promising potential for AI-assisted tools in enhancing the systematic exploration of PMI planning alternatives. This early-stage research contributes to both the theoretical understanding of AI-assisted planning in complex organizational contexts and the practical development of tools to support PMI planning. Future work will focus on refining the underlying models and expanding the evaluation scope to real-world integration scenarios.