Paul Salem, a current member of the MGM Board of Directors and Chair of the real estate committee, will replace Murren as Chair of the Board of Directors.
Hornbuckle was previously MGM's President and COO.
Hornbuckle said: “We have an incredible challenge ahead. We have a talented leadership team, the best employees in the world, and a loyal customer base.
“I have every confidence that MGM Resorts will remain the global entertainment leader once this crisis is contained and it is safe to operate.”
Last month, Murren announced he would be leaving the company at the end of his contract; however, he has vacated the position with immediate effect to head Nevada’s COVID-19 Response, Relief and Recovery Task Force.
The unpaid position will see Murren lead efforts to mobilize the private sector to assist state agencies in the fight against coronavirus.
Murren said: “I fully support accelerating the planned leadership transition to help MGM Resorts address the rapidly changing environment.
“I will continue to dedicate my efforts to help during this uncertain time, and I will be assisting the State of Nevada in its crisis response and recovery efforts.”
