ALLIANT ENERGY RESOURCES, INC.

                                Offer to Exchange
                     Registered 7 3/8% Senior Notes due 2009
      For Any and All Outstanding Unregistered 7 3/8% Senior Notes due 2009


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           THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M., NEW YORK CITY
            TIME, ON ___________, 2000, UNLESS THE OFFER IS EXTENDED.
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                                                              ____________, 1999

To Our Clients:

     Enclosed for your consideration is a Prospectus,  dated ____________,  1999
(the  "Prospectus"),  and the  related  Letter of  Transmittal  (the  "Letter of
Transmittal"),  relating to the offer (the  "Exchange  Offer") of Alliant Energy
Resources,  Inc.  (the  "Company")  to exchange its 7 3/8% Senior Notes due 2009
(the "New Senior Notes") which have been registered  under the Securities Act of
1933, as amended,  for all of its  outstanding  unregistered 7 3/8% Senior Notes
due 2009 (the  "Existing  Senior  Notes"),  upon the terms  and  subject  to the
conditions  described  in the  Prospectus  and the  Letter of  Transmittal.  The
Exchange  Offer is being made in order to  satisfy  certain  obligations  of the
Company  contained in the Registration  Rights Agreement dated November 9, 1999,
by and between the Company and the initial purchasers named therein,  related to
the 7 3/8% Senior Notes due 2009.

     This  material is being  forwarded  to you as the  beneficial  owner of the
Existing  Senior  Notes held by us for your account but not  registered  in your
name.  A tender  of such  Existing  Senior  Notes  may only be made by us as the
holder of record and pursuant to your instructions.

     Accordingly, we request instructions as to whether you wish us to tender on
your behalf the Existing  Senior Notes held by us for your account,  pursuant to
the terms and  conditions  set forth in the  enclosed  Prospectus  and Letter of
Transmittal.  We urge you to read the Prospectus carefully before instructing us
as to whether or not to tender your Existing Senior Notes.

     Your  instructions  should be  forwarded  to us as  promptly as possible in
order to  permit  us to  tender  the  Existing  Senior  Notes on your  behalf in
accordance  with the provisions of the Exchange  Offer.  The Exchange Offer will
expire at 5:00 p.m., New York City time, on ____________,  2000, unless extended
by the Company.  Any Existing  Senior  Notes  tendered  pursuant to the Exchange
Offer may be withdrawn at any time before the Expiration Date.

     If you wish to have us tender your Existing  Senior Notes,  please instruct
us by completing,  executing and returning to us the  instruction  form enclosed
with this letter.  The Letter of Transmittal is furnished to you for information
only and may not be used directly by you to tender Existing Senior Notes.

     If we do not receive written instructions in accordance with the procedures
presented in the Prospectus and the Letter of Transmittal we will not tender any
of the outstanding Existing Senior Notes on your account.