Terry Lanni is stepping down as chief executive of MGM Mirage, the world’s largest gaming group, as doubts emerged about an MBA he claimed to have received from the University of Southern California.

Mr Lanni, who is 65, said in a statement that the time had come to “step aside from full-time engagement and turn over the reins to the new generation”. He is recommending that Jim Murren, MGM Mirage’s chief operating officer, succeed him as chief executive.