Yes, and both companies are now owned by United Technologies.
And previously, EST was owned by General Electric.
We’re getting off topic here, let’s stay on track.
Major bump here… but after a lot of digging I finally figured out how this happened and why they ended up rebranding a direct competitor’s products.
Siemens-branded EST equipment is a holdover from back when Landis & Gyr - a Swiss company with several divisions, including building control - dabbled into the fire alarm market in the US with rebranded EST/FAST equipment. Landis & Gyr had started operating in the US when it acquired Powers (a Chicago-based building control company) in the 1980’s, and would sometimes use “Landis & Gyr Powers” cobranding.
In the mid-1990’s, Landis & Gyr was bought by another Swiss conglomerate known as Elektrowatt. Elektrowatt also owned Cerberus.
Interesting details (available in German only - if you need a translation, go to DeepL which has a reasonably-effective PDF translation option): https://ec.europa.eu/competition/mergers/cases/decisions/m692_de.pdf
Elektrowatt would be purchased by Siemens just a few years later. (A few more years later, the non-building divisions of Landis & Gyr - such as utility meters - would be spun off from Siemens.)
Interesting details: https://ec.europa.eu/competition/mergers/cases/decisions/m913_19971118_600_en.pdf
There is a landis and gyr rebranded siga-278 on eBay for $179 bucks, the front of the box says , landis and Staefa, but it says landis and gyr on the pull station it’s self