Managing multinational brand portfolios requires balancing global consistency with local market adaptation while optimizing synergies across regions, product categories, and consumer segments. As multinational corporations expand, brand portfolios evolve through acquisitions, co-branding, line extensions, and regional localization. This paper synthesizes brand architecture theory, global marketing strategy, cultural adaptation frameworks, and resource-based perspectives to propose the Global Multinational Brand Portfolio Management Framework (G-MBPMF). The model highlights strategic dimensions including brand architecture alignment, regional differentiation, synergy optimization, consumer perception management, and lifecycle control. The study provides insights for corporations managing diverse regional brand identities while maintaining global equity.