While GiG will acquire 75% of Top Games, the remaining 25% will be retained by the local partner.
GiG will now have rights of use to the brand and both companies will work together to operate the business.
GiG is planning on entering the Croatian online casino market through its newfound partnership in the first half of 2020.
Richard Brown, acting CEO of GiG, said: "I’m excited to further expand our B2C business by entering another regulated jurisdiction.
"Croatia is a very interesting marketplace for gambling and supports our strategy to grow our own brands in high potential and regulated markets.
"GiG has a track record of creating responsible gaming experiences with a captivating UX."