Users can bet on global sports via SportsBetting.com, while RaceBook.com is solely focused on racing fans.
To begin with, both brands will target players in Europe and Latin America, through Carousel's Malta Gaming Authority license.
The operator is looking to acquire UK, Swedish and US licenses in the near future.
Carousel obtained a sports betting and casino platform in 2018, which will power the two sites.
Daniel Graetzer, Founder & CEO at Carousel, said: "2018 was a huge year for us as we prepared the business for launch. We closed a second capital raise, acquired two strong domain names and ended the year with the acquisition of our technology platform, but now the real fun starts.
"We’ve assembled a team of highly experienced and competent leaders in our Madrid headquarters and, combined with our recent acquisitions, we are aiming to deliver a superior customer-driven experience to markets all over the world."
