Fluidic Thrust Vectoring (FVT) systems based on Coanda jets are amongst the most promising technologies being considered for future flapless aircraft. One of the core components of a Coanda FTV device is the main jet nozzle, featuring a circular inflow section (at the aft end of the engine) and a high aspect ratio, rectangular outflow section. The aerodynamic performance of this nozzle, in terms of its pressure losses and outflow velocity field distortion, is critical from the control authority point of view, especially at throttle settings typical for low speed maneuvers and approach. The present article reports on an optimization study aimed at finding high quality nozzle shapes based on these considerations.