Abstract: The fuel nozzle includes an annular chamber defined between a housing and a central tube. At the downstream end of the tube, inner and outer swirlers are provided in communication with the upstream chamber and a combustion zone downstream of the swirlers. When fuel gas is supplied the inner swirler, a portion of the air flowing through the chamber mixes in the inner swirler with the supplied fuel for holding a diffusion flame in a downstream diffusion mixing cup. The balance of the air flowing through the chamber through the outer swirler is segregated from the air supplied the inner swirler by a circumferentially extending splitter vane. At an upstream portion of the chamber a plurality of spokes pass into the chamber for supplying fuel gas to the chamber when the nozzle operates in a premix combustion mode. When operating in a premix combustion mode, fuel gas is cut off from the inner swirler and supplied to the spokes.