Most of the big automakes own a lot of different car companies.
Ford owns alot and so does GM. Ford owns Mazda, volvo, Jaguar, Aston Martin, and some others.
GM owns Hummer, and a bunch of others.
Just go to their websites and you will see all their brands. Sometimes automakes work together to make cars. So expensive for R&D that they sometimes share technology. For example the Dodge Stealth and Mitsubishi VR4 were basically the same car. Many other cars were joint ventures. Nothing new.