Creating a CV, many years of professional experience, company changes?

Hello everyone,

I've been working for the same company for 25 years, and now I want to change careers and am creating my first resume. Over time, the company name has changed several times due to mergers and restructuring, or internal company transfers, while the activities have remained more or less the same. How do I include this in my resume? I don't want to give the impression that I've been constantly changing employers…

My ideas so far:

Employee at the employer AG since xx/20xx:

– xx/20xx – xx/20xx Name 1 GmbH: Main activities

– xx/20xx – xx/20xx Name2 GmbH: Main activities

– xx/20xx – xx/20xx Name3 GmbH: Main activities

– xx/20xx – xx/20xx Name4 GmbH:Main areas of activity