The present disclosure relates to methods, arrangements and computer programs for antenna sector configuration for an adaptive antenna system, AAS. A method, performed in a network node, comprises associating (35) wireless devices served from the network node to sectors of a respective sector configuration model based on radio network measurements, wherein the association is performed for each out of a number of sector configuration models. The method further comprises estimating (S37) performance metrics for each sector configuration model based on the associating of wireless devices to sectors of the respective sector configuration model and selecting (S37) an antenna sector configuration of the AAS based on the estimated performance metrics.