Ace has reshuffled its board amid market rumours of job losses.
Operations for the insurance and reinsurance providers will now be divided into two sub-groups, each headed by a group president and chief executive officer.
Dominic Frederico, currently president and chief operating officer of Ace, will take on the role as group president and chief executive officer of the US and Bermuda Group.
The chief executive of Ace Global Markets, John Charman, will also assume the positions of group president and chief executive officer of Ace International Group.
Ace, which has a growth premium of $6bn (£4.1bn) and provides products and services in almost 50 countries, has admitted the restructuring may result in job losses, but these are yet to be confirmed. It currently has assets of about $30bn (£20.5bn) and employs 8,000 people.