Since the PO/Midi had some only partially electrified branch lines in the south of France, they developed a railcar that could run electrically via overhead lines and diesel-electrically. The two vehicles built by Alsthom had the pantograph above the powered bogie and a diesel engine with two generators above the other bogie. Heating was via a steam boiler.

The two vehicles were put into service by the SNCF as the XAT 1000 and were given the nickname “Autorail amphibie”. From Bordeaux they ran the first part east under overhead wire and continued to Bergerac or Périgueux using the diesel engine. During the Second World War, due to the lack of fuel, they ran almost exclusively on electric power, while after the war they ran almost exclusively on diesel-electric power. In 1952, even the electrical operation equipment was removed, while two smaller diesel engines of 209 kW each were installed. They continued to operate in this configuration until 1959.