FILE PHOTO: Leon Black, Chairman, CEO and Director, Apollo Global Management, LLC, speaks at the Milken Institute's 21st Global Conference in Beverly Hills, California, U.S. May 1, 2018. REUTERS/Lucy Nicholson/File Photo Billionaire and co-founder of Apollo Global Management Leon Black has sold shares worth about $172.8 million in the private equity firm, nearly three years after stepping down as its chief executive. He sold 1.55 million shares earlier this month, a regulatory disclosure by Black made late on Monday showed.