Greenberg joined ACE in 2001 having left AIG ( then headed by his father) at the age of 45. By 2004 he was CEO and has overseen 15 major acquisitions. In 2010 a major purchase saw ACE become one of the US biggest crop insurers wile a 2013 purchase saw the insurer become one of the major auto insurers in Mexico. It’s not yet known whether Greenberg’s move is to help with the insurance giant’s digestion, or whether it’s still hungry.