Kontomerkos will officially move aside from the role on March 31, with current chief operating officer Ray Pineault to step in as interim chief executive, subject to regulatory approvals.
Kontomerkos joined MGE in September 2011 as chief financial officer, remaining in the role until October 2017, after which he went on to serve as CEO.
“During his tenure with the organisation, first as CFO and more recently as CEO, Mario played a critical role in the growth and success of the organisation,” Mohegan Tribe chairman James Gessner, Jr. said.
“We thank Mario for his many years of service to the Tribe and MGE, more recently navigating the company successfully through the ongoing global pandemic as well as a major refinancing earlier this year.”