We present a MIP-based airspace sectorization framework for Terminal Maneuvering Areas (TMAs). It incorporates an airspace complexity representation, as well as various constraints on the sectors' geometry, e.g., the requirement that points that demand increased attention from air traffic controllers should lie in the sector's interior to allow for enough time to resolve possible conflicts. In contrast to earlier integer/constraint programming approaches, which used synthesis methods with variables per elementary airspace piece that were glued together to form sectors, our IP formulation uses a variable per potential edge on the sector boundary. It is also the first step towards an integrated design of routes, the resulting complexity, and a sectorization. We present results for Stockholm TMA.