Coleman became chief executive of Microgaming in June 2018, after serving as chief financial officer for nearly 14 years.
He replaced long-serving CEO Roger Raatgever in the position.
“I am honored to have led Microgaming as CEO – such an incredible business and people,” Coleman said.
“After 17 years at the company, this is a natural time for me personally to embark on the next adventure.
New Microgaming CEO Andrew Clucas “Microgaming has a strong leadership structure in place and an exciting future ahead, and I am delighted to announce Andrew Clucas as my successor.
Andy is a brilliant colleague, friend, and leader, and I have every confidence that he will steer Microgaming to new success.”
Coleman will step down from the CEO role on 31 December, with operations chief Clucas replacing him.
Clucas joined Microgaming in 2009 after a career in the Royal Air Force and has held various roles in business development and sales.
He was promoted to chief operating officer in January 2018.
Clucas paid tribute to Coleman, describing him as “an outstanding leader and ambassador of the business for almost two decades”.
“I cannot praise him highly enough for his many achievements and contributions,” Clucas added.
“I am delighted to be picking up the mantle from him; being appointed CEO of Microgaming is an incredible honor, and I intend to lead the business with the very same passion and commitment.”