Exhibit 99.1

   Written Statement of the Chairman, President and Chief Executive Officer
                          Pursuant to 18 U.S.C. Section 1350

Solely  for the  purposes  of  complying  with 18 U.S.C.  Section  1350,  I, the
undersigned  Chairman,  President and Chief Executive  Officer of Alliant Energy
Corporation (the  "Company"),  hereby certify,  based on my knowledge,  that the
Annual  Report on Form 10-K of the Company for the year ended  December 31, 2002
(the  "Report")  fully  complies with the  requirements  of Section 13(a) of the
Securities  Exchange  Act of 1934 and that  information  contained in the Report
fairly presents,  in all material respects,  the financial condition and results
of operations of the Company.


/s/ Erroll B. Davis, Jr.
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Erroll B. Davis, Jr.
March 25, 2003