Since almost all tracks in the stations in Switzerland were electrified early on, electric shunting tractors were purchased for light marshalling services. For this purpose, the SLM manufactured the Te III from 1941 using the electrical part from SAAS. One axle was driven by a nose-suspended motor and was connected to the second axle via coupling rods.
The SBB initially only received six TeIII. A total of 19 more were purchased by various private railways, some of which were referred to as Ce 2/2 from the start. The SBB later redesignated its TeIII as Ce 2/2 and took over additional locomotives from private railways. 