Recent technologicaladvancements are increasingly pressuring Telcos to deliver high-performance, customizable networks. One effective solution is to offer private networks tailored to specific use cases. This paper introduces a blockchain-based platform for Telcos for the delivery of private 5G networks as-a-service. The platform serves three functions: a marketplace connecting supply and demand, a network integrator for onboarding and integrating network assets, and a connectivity manager ensuring performance accountability. A proof-of-concept demonstrates the solution's feasibility.