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<TITLE>Form 8-K</TITLE>
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 <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM 8-K
</B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>CURRENT REPORT </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Pursuant
to Section&nbsp;13 or 15(d) </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>of the Securities Exchange Act of 1934 </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Date of Report </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>(Date of
earliest event reported): October&nbsp;3, 2013 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Commission</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1.00pt solid #000000; width:54.20pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>File&nbsp;Number</B></P></TD>
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<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Name&nbsp;of&nbsp;Registrant,&nbsp;State&nbsp;of&nbsp;Incorporation,&nbsp;Address&nbsp;of</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Principal&nbsp;Executive&nbsp;Offices&nbsp;and&nbsp;Telephone&nbsp;Number</B></P></TD>
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<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>IRS Employer</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1.00pt solid #000000; width:95.95pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Identification&nbsp;Number</B></P></TD></TR>


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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">1-9894</P></TD>
<TD VALIGN="bottom"><FONT STYLE="font-size:8pt">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Alliant Energy Corporation</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(a Wisconsin
corporation)</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">4902 N. Biltmore Lane</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Madison, Wisconsin
53718</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Telephone (608) 458-3311</P></TD>
<TD VALIGN="bottom"><FONT STYLE="font-size:8pt">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top">39-1380265</TD></TR>
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<TD VALIGN="top"> <P STYLE="margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">1-4117</P></TD>
<TD VALIGN="bottom"><FONT STYLE="font-size:8pt">&nbsp;&nbsp;&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Interstate Power and Light Company</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">(an Iowa
corporation)</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Alliant Energy Tower</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Cedar Rapids, Iowa
52401</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">Telephone (319) 786-4411</P></TD>
<TD VALIGN="bottom"><FONT STYLE="font-size:8pt">&nbsp;&nbsp;</FONT></TD>
<TD VALIGN="top">42-0331370</TD></TR>
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<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">This combined Form 8-K is separately filed by Alliant Energy Corporation and Interstate Power and Light Company. </P>
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<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any
of the following provisions: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></TD>
<TD ALIGN="left" VALIGN="top">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD ALIGN="left" VALIGN="top">Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT STYLE="FONT-FAMILY:WINGDINGS">&#168;</FONT></TD>
<TD ALIGN="left" VALIGN="top">Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD ALIGN="left" VALIGN="top">Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) </TD></TR></TABLE> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>

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<TD WIDTH="9%" VALIGN="top" ALIGN="left"><U>Item&nbsp;2.03.</U></TD>
<TD ALIGN="left" VALIGN="top"><U>Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. </U></TD></TR></TABLE>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">On October&nbsp;3, 2013, Interstate Power and Light Company (&#147;IPL&#148;), a subsidiary of Alliant Energy Corporation, entered into an
Underwriting Agreement (the &#147;Underwriting Agreement&#148;) with Goldman, Sachs&nbsp;&amp; Co., Mitsubishi UFJ Securities (USA), Inc. and RBS Securities Inc. as representatives of the several underwriters listed therein (the
&#147;Underwriters&#148;), pursuant to which IPL agreed to sell, and the Underwriters agreed to purchase, subject to the terms and conditions set forth therein, $250,000,000 aggregate principal amount of IPL&#146;s 4.70% Senior Debentures due 2043
(the &#147;Debentures&#148;), in a public offering (the &#147;Offering&#148;). The Offering closed on&nbsp;October 8, 2013. The description of the Underwriting Agreement set forth above is qualified by reference to the Underwriting Agreement filed
as Exhibit 1.1 to this Current Report on Form 8-K and incorporated herein by reference. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Debentures were issued under an Indenture
(the &#147;Indenture&#148;), dated as of August&nbsp;20, 2003, between IPL and The Bank of New York Mellon Trust Company, N.A., as Trustee (the &#147;Trustee&#148;), pursuant to an Officer&#146;s Certificate, dated as of October&nbsp;8, 2013 (the
&#147;Certificate&#148;). The Certificate provides, among other things, that the Debentures will bear interest at a rate of 4.70%&nbsp;per year (payable on April&nbsp;15 and October&nbsp;15 of each year, beginning on April&nbsp;15, 2014), and will
mature on October&nbsp;15, 2043. IPL may redeem the Debentures at any time or from time to time prior to April&nbsp;15, 2043 at a &#147;make-whole&#148; redemption price, plus accrued and unpaid interest to, but not including, the date of
redemption. At any time on or after April&nbsp;15, 2043, IPL may redeem the Debentures at par, plus accrued and unpaid interest to, but not including, the date of redemption. The Indenture contains customary events of default. If an event of default
occurs and is continuing with respect to any series of the Debentures, then the Trustee or the holders of at least 33% of the principal amount of the outstanding Debentures of that series may declare the Debentures of that series to be due and
payable immediately. The description of the Certificate set forth above is qualified by reference to the Certificate filed as Exhibit 4.1 to this Current Report on Form 8-K and incorporated by reference herein. </P>
<P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="9%" VALIGN="top" ALIGN="left"><U>Item&nbsp;8.01.</U></TD>
<TD ALIGN="left" VALIGN="top"><U>Other Events. </U></TD></TR></TABLE> <P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">The Debentures are registered under the Securities Act of 1933, as
amended, pursuant to a Registration Statement on Form S-3 (Registration No.&nbsp;333-178577-02) that IPL filed with the Securities and Exchange Commission (the &#147;SEC&#148;). IPL is filing certain exhibits as part of this Current Report on Form
8-K in connection with its filing with the SEC of a final prospectus supplement, dated October&nbsp;3, 2013, and a prospectus, dated December&nbsp;16, 2011, relating to the Offering. See &#147;Item 9.01. Financial Statements and Exhibits.&#148; </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">On October&nbsp;3, 2013, IPL issued a press release announcing that it had priced the Offering. The press release is filed as Exhibit 99.1 to
this Current Report on Form 8-K and is incorporated herein by reference. </P>
 <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">-1- </P>


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<TD WIDTH="9%" VALIGN="top" ALIGN="left"><U>Item&nbsp;9.01.</U></TD>
<TD ALIGN="left" VALIGN="top"><U>Financial Statements and Exhibits. </U></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left">(a)</TD>
<TD ALIGN="left" VALIGN="top">Not applicable. </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(b)</TD>
<TD ALIGN="left" VALIGN="top">Not applicable. </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left">(c)</TD>
<TD ALIGN="left" VALIGN="top">Not applicable. </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(d)</TD>
<TD ALIGN="left" VALIGN="top"><U>Exhibits</U>. The following exhibits are being filed herewith: </TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><DIV ALIGN="right">
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(1.1)</TD>
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<TD VALIGN="top">Underwriting Agreement, dated October&nbsp;3, 2013, among Interstate Power and Light Company and the underwriters named therein.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(4.1)</TD>
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<TD VALIGN="top">Officer&#146;s Certificate, dated October&nbsp;8, 2013, creating the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(5.1)</TD>
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<TD VALIGN="top">Opinion of Cravath, Swaine&nbsp;&amp; Moore LLP, dated October&nbsp;8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(5.2)</TD>
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<TD VALIGN="top">Opinion of Nyemaster Goode, P.C., dated October&nbsp;8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>(23.1)</TD>
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<TD VALIGN="top">Consent of Cravath, Swaine&nbsp;&amp; Moore LLP (contained in Exhibit (5.1)&nbsp;hereto).</TD></TR>
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<TD VALIGN="top" NOWRAP>(23.2)</TD>
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<TD VALIGN="top">Consent of Nyemaster Goode, P.C. (contained in Exhibit (5.2)&nbsp;hereto).</TD></TR>
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<TD VALIGN="top" NOWRAP>(99.1)</TD>
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<TD VALIGN="top">Press release of Interstate Power and Light Company, dated October&nbsp;3, 2013.</TD></TR>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><U>SIGNATURES </U></B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation and Interstate Power and Light Company have
each duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top" COLSPAN="3"><B>ALLIANT ENERGY CORPORATION</B></TD></TR>
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<TD VALIGN="top">By:</TD>
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<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Thomas L. Hanson</P></TD></TR>
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<TD VALIGN="top">Date: October&nbsp;8, 2013</TD>
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<TD VALIGN="top">Thomas L. Hanson</TD></TR>
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<TD VALIGN="top">Senior Vice President and Chief Financial Officer</TD></TR>
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<TD VALIGN="top" COLSPAN="3"><B>INTERSTATE POWER AND LIGHT COMPANY</B></TD></TR>
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<TD VALIGN="top">By:</TD>
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<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Thomas L. Hanson</P></TD></TR>
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<TD VALIGN="top">Date: October&nbsp;8, 2013</TD>
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<TD VALIGN="top">Thomas L. Hanson</TD></TR>
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<TD VALIGN="top">Senior Vice President and Chief Financial Officer</TD></TR>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">ALLIANT ENERGY CORPORATION </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">INTERSTATE POWER AND LIGHT COMPANY </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Exhibit Index to Current Report on Form 8-K </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Dated October&nbsp;8, 2013 </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" NOWRAP ALIGN="center"> <P STYLE="border-bottom:1.00pt solid #000000; width:28.45pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Exhibit<BR>Number</B></P></TD>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(1.1)</TD>
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<TD VALIGN="top">Underwriting Agreement, dated October 3, 2013, among Interstate Power and Light Company and the underwriters named therein.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(4.1)</TD>
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<TD VALIGN="top">Officer&#146;s Certificate, dated October 8, 2013, creating the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(5.1)</TD>
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<TD VALIGN="top">Opinion of Cravath, Swaine &amp; Moore LLP, dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>&nbsp;&nbsp;(5.2)</TD>
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<TD VALIGN="top">Opinion of Nyemaster Goode, P.C., dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.</TD></TR>
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<TD VALIGN="top" NOWRAP>(23.1)</TD>
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<TD VALIGN="top">Consent of Cravath, Swaine &amp; Moore LLP (contained in Exhibit (5.1) hereto).</TD></TR>
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<TD VALIGN="top" NOWRAP>(23.2)</TD>
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<TD VALIGN="top">Consent of Nyemaster Goode, P.C. (contained in Exhibit (5.2) hereto).</TD></TR>
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<TD VALIGN="top" NOWRAP>(99.1)</TD>
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<TD VALIGN="top">Press release of Interstate Power and Light Company, dated October 3, 2013.</TD></TR>
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[{"company-data": {"conformed-name": "ALLIANT ENERGY CORP", "cik": "0000352541", "assigned-sic": "4931", "irs-number": "391380265", "state-of-incorporation": "WI", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-09894", "film-number": "131141353"}, "business-address": {"street1": "4902 NORTH BILTMORE LANE", "street2": "SUITE 1000", "city": "MADISON", "state": "WI", "zip": "53718-2148", "phone": "608-458-3311"}, "mail-address": {"street1": "4902 NORTH BILTMORE LANE", "street2": "SUITE 1000", "city": "MADISON", "state": "WI", "zip": "53718-2148"}, "former-company": [{"former-conformed-name": "INTERSTATE ENERGY CORP", "date-changed": "19980427"}, {"former-conformed-name": "WPL HOLDINGS INC", "date-changed": "19920703"}]}, {"company-data": {"conformed-name": "INTERSTATE POWER & LIGHT CO", "cik": "0000052485", "assigned-sic": "4931", "irs-number": "420331370", "state-of-incorporation": "IA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-04117", "film-number": "131141354"}, "business-address": {"street1": "200 FIRST ST SE", "street2": "ALLIANT ENERGY TOWER", "city": "CEDAR RAPIDS", "state": "IA", "zip": "52401", "phone": "3193984411"}, "mail-address": {"street1": "200 FIRST ST SE", "street2": "ALLIANT ENERGY TOWER", "city": "CEDAR RAPIDS", "state": "IA", "zip": "52401"}, "former-company": [{"former-conformed-name": "IES UTILITIES INC", "date-changed": "20020103"}, {"former-conformed-name": "IES UTILITIES INC", "date-changed": "19940107"}, {"former-conformed-name": "IOWA ELECTRIC LIGHT & POWER CO", "date-changed": "19920703"}]}]
Form 8-K
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant
to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of Report
(Date of
earliest event reported): October 3, 2013
Commission
File Number
Name of Registrant, State of Incorporation, Address of
Principal Executive Offices and Telephone Number
IRS Employer
Identification Number
1-9894
Alliant Energy Corporation
(a Wisconsin
corporation)
4902 N. Biltmore Lane
Madison, Wisconsin
53718
Telephone (608) 458-3311
39-1380265
1-4117
Interstate Power and Light Company
(an Iowa
corporation)
Alliant Energy Tower
Cedar Rapids, Iowa
52401
Telephone (319) 786-4411
42-0331370
This combined Form 8-K is separately filed by Alliant Energy Corporation and Interstate Power and Light Company.
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any
of the following provisions:
¨
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
¨
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
¨
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
¨
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Item 2.03.
Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.
On October 3, 2013, Interstate Power and Light Company ("IPL"), a subsidiary of Alliant Energy Corporation, entered into an
Underwriting Agreement (the "Underwriting Agreement") with Goldman, Sachs & Co., Mitsubishi UFJ Securities (USA), Inc. and RBS Securities Inc. as representatives of the several underwriters listed therein (the
"Underwriters"), pursuant to which IPL agreed to sell, and the Underwriters agreed to purchase, subject to the terms and conditions set forth therein, $250,000,000 aggregate principal amount of IPL's 4.70% Senior Debentures due 2043
(the "Debentures"), in a public offering (the "Offering"). The Offering closed on October 8, 2013. The description of the Underwriting Agreement set forth above is qualified by reference to the Underwriting Agreement filed
as Exhibit 1.1 to this Current Report on Form 8-K and incorporated herein by reference.
The Debentures were issued under an Indenture
(the "Indenture"), dated as of August 20, 2003, between IPL and The Bank of New York Mellon Trust Company, N.A., as Trustee (the "Trustee"), pursuant to an Officer's Certificate, dated as of October 8, 2013 (the
"Certificate"). The Certificate provides, among other things, that the Debentures will bear interest at a rate of 4.70% per year (payable on April 15 and October 15 of each year, beginning on April 15, 2014), and will
mature on October 15, 2043. IPL may redeem the Debentures at any time or from time to time prior to April 15, 2043 at a "make-whole" redemption price, plus accrued and unpaid interest to, but not including, the date of
redemption. At any time on or after April 15, 2043, IPL may redeem the Debentures at par, plus accrued and unpaid interest to, but not including, the date of redemption. The Indenture contains customary events of default. If an event of default
occurs and is continuing with respect to any series of the Debentures, then the Trustee or the holders of at least 33% of the principal amount of the outstanding Debentures of that series may declare the Debentures of that series to be due and
payable immediately. The description of the Certificate set forth above is qualified by reference to the Certificate filed as Exhibit 4.1 to this Current Report on Form 8-K and incorporated by reference herein.
Item 8.01.
Other Events.
The Debentures are registered under the Securities Act of 1933, as
amended, pursuant to a Registration Statement on Form S-3 (Registration No. 333-178577-02) that IPL filed with the Securities and Exchange Commission (the "SEC"). IPL is filing certain exhibits as part of this Current Report on Form
8-K in connection with its filing with the SEC of a final prospectus supplement, dated October 3, 2013, and a prospectus, dated December 16, 2011, relating to the Offering. See "Item 9.01. Financial Statements and Exhibits."
On October 3, 2013, IPL issued a press release announcing that it had priced the Offering. The press release is filed as Exhibit 99.1 to
this Current Report on Form 8-K and is incorporated herein by reference.
-1-
Item 9.01.
Financial Statements and Exhibits.
(a)
Not applicable.
(b)
Not applicable.
(c)
Not applicable.
(d)
Exhibits
. The following exhibits are being filed herewith:
(1.1)
Underwriting Agreement, dated October 3, 2013, among Interstate Power and Light Company and the underwriters named therein.
(4.1)
Officer's Certificate, dated October 8, 2013, creating the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(5.1)
Opinion of Cravath, Swaine & Moore LLP, dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(5.2)
Opinion of Nyemaster Goode, P.C., dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(23.1)
Consent of Cravath, Swaine & Moore LLP (contained in Exhibit (5.1) hereto).
(23.2)
Consent of Nyemaster Goode, P.C. (contained in Exhibit (5.2) hereto).
(99.1)
Press release of Interstate Power and Light Company, dated October 3, 2013.
-2-
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation and Interstate Power and Light Company have
each duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
ALLIANT ENERGY CORPORATION
By:
/s/ Thomas L. Hanson
Date: October 8, 2013
Thomas L. Hanson
Senior Vice President and Chief Financial Officer
INTERSTATE POWER AND LIGHT COMPANY
By:
/s/ Thomas L. Hanson
Date: October 8, 2013
Thomas L. Hanson
Senior Vice President and Chief Financial Officer
-3-
ALLIANT ENERGY CORPORATION
INTERSTATE POWER AND LIGHT COMPANY
Exhibit Index to Current Report on Form 8-K
Dated October 8, 2013
Exhibit
Number
(1.1)
Underwriting Agreement, dated October 3, 2013, among Interstate Power and Light Company and the underwriters named therein.
(4.1)
Officer's Certificate, dated October 8, 2013, creating the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(5.1)
Opinion of Cravath, Swaine & Moore LLP, dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(5.2)
Opinion of Nyemaster Goode, P.C., dated October 8, 2013, with respect to the 4.70% Senior Debentures due 2043 of Interstate Power and Light Company.
(23.1)
Consent of Cravath, Swaine & Moore LLP (contained in Exhibit (5.1) hereto).
(23.2)
Consent of Nyemaster Goode, P.C. (contained in Exhibit (5.2) hereto).
(99.1)
Press release of Interstate Power and Light Company, dated October 3, 2013.