The big rotating bladed thing on the front of an airliner engine, the "fan", serves as the first one or few stages of the gas turbine compressor. The efficiency of axial compressors is about 95% and the fan stages are at least as good. Most of the air exiting the fan doesn't end up in the combustor, however, but is expanded through an annular nozzle which provides almost all of the thrust. The core engine dia is small compared to the fan.
Nozzle efficiency is also 95% so the over efficiency of a fan is about
90% -- higher than any prop.
Bret Cahill