WISCONSIN POWER AND LIGHT COMPANY (a Wisconsin corporation) 4.60% DEBENTURES DUE 2020 PURCHASE AGREEMENT Dated: June 10, 2010Purchase Agreement • June 11th, 2010 • Alliant Energy Corp • Electric & other services combined • New York
Wisconsin Power and Light Company, a Wisconsin corporation (the “Company”), confirms its agreement with RBS Securities Inc. (“RBS”) and UBS Securities LLC (“UBS”), and each of the other underwriters named in Schedule A hereto (collectively, the “Underwriters”, which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom RBS and UBS are acting as representatives (in such capacity, the “Representatives”), with respect to the issue and sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective principal amounts set forth on Schedule A of $150,000,000 aggregate principal amount of the Company’s 4.60% Debentures due 2020 (the “Securities”). The Securities will be issued pursuant to an indenture dated as of June 20, 1997 (the “Base Indenture”) between the Company and Wells Fargo Bank, National Association, as successor in interest to U.S. Bank National Association, as trustee (the “Trustee
