Diarmuid is the President and Chief Executive Officer of Global Excess Partners LLC. His professional experience includes service as Senior Vice President of the Home Insurance Company, Chairman of Commonwealth Insurance Company of Canada, Vice President and General Manager of the International Reinsurance Division at Johnson & Higgins, Inc., President and Chief Operating Officer of Northumberland General Insurance Company, and General Manager of American International Group's Canadian operations. He received an M.B.A. from Columbia University.