The casino operator said the Nevada Gaming Commission unanimously approved the deal Thursday.
"We are very pleased with the Commission's unanimous approval, and we are working diligently to complete the remaining steps of the merger prior to the end of March," said Terry Lanni, MGM Mirage's chief executive.
Last week the merger got approval from the Federal Trade Commission. Nevada regulators were widely expected to follow the FTC's lead in making their decision.The deal must still get the nod from Illinois and Michigan regulators. MGM Mirage shares were up 73 cents, or 1.0%, at $75.38.