(a) | Aon North America, Inc., a Delaware corporation (the “Issuer”), agrees with the several underwriters named in Exhibit A hereto (the “Underwriters”) to issue and sell to the several Underwriters $600,000,000 principal amount of its 5.125% Senior Notes due 2027 (the “2027 Notes”), $1,000,000,000 principal amount of its 5.150% Senior Notes due 2029 (the “2029 Notes”), $650,000,000 principal amount of its 5.300% Senior Notes due 2031 (the “2031 Notes”), $1,750,000,000 principal amount of its 5.450% Senior Notes due 2034 (the “2034 Notes”) and $2,000,000,000 principal amount of its 5.750% Senior Notes due 2054 (the “2054 Notes” and, together with the 2027 Notes, the 2029 Notes, the 2031 Notes and the 2034 Notes, the “Notes”), to be issued under an indenture dated as of the Closing Date (as defined below) (the “Base Indenture”), among the Issuer, the Guarantors (as defined below) and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”), as supplemented by a supplemental indenture to be dated as of the Closing Date (the “Supplemental Indenture” and, together with the Base Indenture, the “Indenture”) among the Issuer, the Guarantors and the Trustee. The Notes will be fully and unconditionally guaranteed as to the payment of principal and interest by Aon plc, a public limited company formed under the laws of Ireland (“Aon plc”), Aon Corporation, a Delaware corporation (“Aon Corporation”), Aon Global Limited, a private limited company incorporated under the laws of England and Wales (“AGL”), and Aon Global Holdings plc, a public limited company incorporated under the laws of England and Wales (“AGH” and, together with Aon plc, Aon Corporation and AGL, the “Guarantors,” and each, a “Guarantor,” and such guarantees, the “Guarantees”). The Notes, together with the Guarantees, are referred to in this Agreement as the “Securities.” |