An array transducer probe has transducer elements arranged in adjacent patches (62, 64, 66) of groups of transducer elements. A microbeamformer in the probe is coupled to the elements of the array to transmit ultrasound beams and delay echo signals received by the transducer elements. In a standard configuration the elements of each patch (62, 64, 66) are coupled to the summing node (72, 74, 76) of that patch. The elements of each patch may also be coupled to the summing nodes of one or more adjacent patches. For multiline (4′, 6′) reception some of the elements of the active aperture are coupled to the summing node of one patch, and other elements of the active aperture are coupled to the summing node of another patch. This coupling provides at least two different patch signals to channels (82, 84) of a system beamformer for multiline processing.