With the electrification of the Ligne de Sceaux in the south of Paris, new electric railcars were ordered, which should combine good acceleration with a quick change of passengers. The vehicles were based on the Métro's Sprague-Thomson trains and had the railway's larger loading gauge. There were four doors per side and a driver's cab at one end. The basic unit consisted of two railcars, both of which were powered. Up to four of these units were combined into a train. They were later used by the RATP also on other routes and were retired between 1984 and 1987. 