The aim of this paper is to analyze the location decisions both of producer services and of manufacturing, exploring two main topics: how manufacturing and services location change when regions integrate, and how developments in telecommunications affect them both. We built a theoretical model consisting of two regions and three sectors (manufacturing, producer services, and agriculture). Given that producer services constitute a sector oriented towards information and knowledge, this is a factor that is taken into account in the explanation of their location. Numerical simulations are made in a general equilibrium framework. In contrast to previous works, we find that when regions integrate, specialization (producer services being in the core regions, and manufacturing in the periphery) -- rather than convergence -- arises. Besides, improvements in telecommunications may facilitate concentration of services in the core regions.