IIRC the rights to the Nernst lamp in the US was sold to George Westinghouse, who then started the Nernst Lamp Company in 1901.
Here's a link to some US literature. Interesting there were two models made, a three glower model with a internal ballast for hardwired installation and a single glower "self ballasted" model with a screw base for retrofitting incandescent lamp sockets.