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  Quarterly  Report on Form 10-Q of the Company
for the quarter  ended March 31, 2003 (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.
May 15, 2003

A signed original of this written statement required by Section 906 has been
provided to the Company and will be retained by the Company and furnished to
the Securities and Exchange Commission or its staff upon request.