It's not official yet (well the fact that BMW will have a 4th brand is), but rumours point to the possibility that BMW's new brand will compete in the small car category (think Smart or VW Up), focusing on new alternatives for urban mobility. A new architecture, new urban mobility, new design paradigm and... hybrid and full electric powertrains. Yes, full electric. Could use the name Isetta, an icon from BMW in the 60's, or get a completely new name.
There have been some indications about this new brand, even in Bangle's interviews and some famous marketing-related insiders have also hinted at the electric powertrain. We have a source from a tier-1 supplier that confirms the process is in motion. Just for illustration, an electric concept car from BMW in the 90's, the E1: