Public bus organizations in major cities around the world often outsource bus routes to private sectors through competitive tendering, with the goal of increasing efficiency and reducing operational costs. A key issue for decision-makers in this context is determining the optimal arrangement of routes in bid packages. This paper proposes a model for optimal packaging of bus routes, considering key indicators such as package size, package revenue, and the geographical proximity of routes. The proposed solution method is based on a genetic algorithm, which utilizes heuristic techniques and can be implemented in large-scale networks. The model and method were tested on the city of Tehran, involving 156 bus routes and 14 existing packages under two different scenarios. In the first scenario, the number of packages remained the same as the current situation, but the arrangement of routes within the packages was optimized. As a result, revenue deviation between the proposed packages was reduced by 29%. In the second scenario, the optimal packaging was determined without considering the current number of packages, which resulted in the introduction of 10 optimized packages. The results showed that revenue deviation between packages was approximately 62% lower than the current situation. Furthermore, the routes within the packages exhibited significant improvement in terms of geographical proximity, leading to reduced operational costs and subsequently lower bid prices in the tender process.