UNITED STATESSECURITIES AND EXCHANGE
COMMISSIONWASHINGTON, D.C. 20549

FORM 10-Q

|[X]    | QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE 
|------ | -----------------------------------------------------------------------------
|       | ACT OF 1934                                                                  
|       | For the quarterly period ended March 31, 2004                                
|       |                                                                              
|or    
|       |                                                                              
|[    ] | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE
|       | ACT OF 1934                                                                  
|       | For the transition period from _______ to _______                            

|Commission  | Name of Registrant, State of Incorporation,                 | IRS Employer         
|----------- | ----------------------------------------------------------- | ---------------------
|File Number | Address of Principal Executive Offices and Telephone Number | Identification Number
|1-9894      | ALLIANT ENERGY CORPORATION                                  | 39-1380265           
|            | (a Wisconsin corporation)                                  
|            | 4902 N. Biltmore Lane                                      
|            | Madison, Wisconsin 53718                                   
|            | Telephone (608)458-3311                                    
|           
|0-4117-1    | INTERSTATE POWER AND LIGHT COMPANY                          | 42-0331370           
|            | (an Iowa corporation)                                      
|            | Alliant Energy Tower                                       
|            | Cedar Rapids, Iowa 52401                                   
|            | Telephone (319)786-4411                                    
|           
|0-337       | WISCONSIN POWER AND LIGHT COMPANY                           | 39-0714890           
|            | (a Wisconsin corporation)                                  
|            | 4902 N. Biltmore Lane                                      
|            | Madison, Wisconsin 53718                                   
|            | Telephone (608)458-3311                                    

This combined Form 10-Q is separately
filed by Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin
Power and Light Company. Information contained in the Form 10-Q relating to Interstate
Power and Light Company and Wisconsin Power and Light Company is filed by such registrant
on its own behalf. Each of Interstate Power and Light Company and Wisconsin Power and
Light Company makes no representation as to information relating to registrants other than
itself.

Indicate by check mark whether the
registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the
Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period
that the registrants were required to file such reports), and (2) have been subject to
such filing requirements for the past 90 days. Yes [ X ] No [     ]

|Indicate by check mark whether the registrants are accelerated filers (as defined in Rule 12b-2 of the Exchange Act).
|---------------------------------------------------------------------------------------------------------------------
|Alliant Energy Corporation                                                                                           
|Interstate Power and Light Company                                                                                   
|Wisconsin Power and Light Company                                                                                    

|Number of shares outstanding of each class of common stock as of April 30, 2004:
|--------------------------------------------------------------------------------
|Alliant Energy Corporation                                                      
|                                                                                
|Interstate Power and Light Company                                              
|                                                                                
|                                                                                
|Wisconsin Power and Light Company                                               
|                                                                                

|TABLE OF CONTENTS
|-----------------
|                 
|Part I.          
|Item 1.          
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|                 
|Item 2.          
|Item 3.          
|Item 4.          
|Part II.         
|Item 1.          
|Item 6.          
|                 

|DEFINITIONS                                                                                               
|----------------------------------------------------------------------------------------------------------
|Certain abbreviations or acronyms used in the text and notes of this combined Form 10-Q are defined below:
|Abbreviation or Acronym                                                                                   
|Alliant Energy                                                                                            
|ATC                                                                                                       
|Corporate Services                                                                                        
|Dth                                                                                                       
|EBITDA                                                                                                    
|EITF                                                                                                      
|Emery                                                                                                     
|EPS                                                                                                       
|FIN                                                                                                       
|FIN 46                                                                                                    
|GAAP                                                                                                      
|IP&L                                                                                                      
|IUB                                                                                                       
|Kewaunee                                                                                                  
|MD&A                                                                                                      
|MPUC                                                                                                      
|MW                                                                                                        
|MWh                                                                                                       
|N/A                                                                                                       
|PSCW                                                                                                      
|PUHCA                                                                                                     
|Resources                                                                                                 
|SEC                                                                                                       
|SFAS                                                                                                      
|SFAS 143                                                                                                  
|South Beloit                                                                                              
|TBD                                                                                                       
|U.S.                                                                                                      
|WP&L                                                                                                      
|WPC                                                                                                       

1

PART I. FINANCIAL
INFORMATION

ITEM 1.  CONDENSED CONSOLIDATED
FINANCIAL STATEMENTS (UNAUDITED)

ALLIANT ENERGY
CORPORATION                      CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

|                                                                    | For the Three Months Ended March 31,    
|------------------------------------------------------------------- | ----------------------------------------
|                                                                    | 2004                                    
|                                                                   
|                                                                    | (in thousands, except per share amounts)
|Operating revenues:                                                
|Domestic utility:                                                  
|Electric                                                            |                                         
|Gas                                                                 |                                         
|Other                                                               |                                         
|Non-regulated                                                       |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                   
|Operating expenses:                                                 |                                         
|Domestic utility:                                                   |                                         
|Electric production fuel and purchased power                        |                                         
|Cost of gas sold                                                    |                                         
|Other operation and maintenance                                     |                                         
|Non-regulated operation and maintenance                             |                                         
|Depreciation and amortization                                       |                                         
|Taxes other than income taxes                                       |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                   
|Operating income                                                    |                                         
|                                                                    |                                         
|                                                                   
|Interest expense and other:                                         |                                         
|Interest expense                                                    |                                         
|Loss on early extinguishment of debt                                |                                         
|Equity (income) loss from unconsolidated investments                |                                         
|Allowance for funds used during construction                        |                                         
|Preferred dividend requirements of subsidiaries                     |                                         
|Interest income and other                                           |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                    |                                         
|                                                                   
|Income from continuing operations before income taxes               |                                         
|                                                                    |                                         
|                                                                   
|Income taxes                                                        |                                         
|                                                                    |                                         
|                                                                   
|Income from continuing operations                                   |                                         
|                                                                    |                                         
|                                                                   
|Loss from discontinued operations, net of tax (Note 7)              |                                         
|                                                                    |                                         
|                                                                   
|Income before cumulative effect of changes in accounting principles |                                         
|                                                                    |                                         
|                                                                   
|Cumulative effect of changes in accounting principles, net of tax   |                                         
|                                                                    |                                         
|                                                                   
|Net income (loss)                                                   |                                         
|                                                                    |                                         
|                                                                   
|Average number of common shares outstanding (basic)                 |                                         
|                                                                    |                                         
|                                                                   
|Average number of common shares outstanding (diluted)               |                                         
|                                                                    |                                         
|                                                                   
|Earnings per average common share (basic and diluted):              |                                         
|Income from continuing operations                                   |                                         
|Loss from discontinued operations                                   |                                         
|Cumulative effect of changes in accounting principles               |                                         
|                                                                    |                                         
|Net income (loss)                                                   |                                         
|                                                                    |                                         
|                                                                   
|Dividends declared per common share                                 |                                         
|                                                                    |                                         
|                                                                   

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

2

ALLIANT ENERGY
CORPORATION                                    CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED)

|                                                                         | March 31,      | December 31,
|------------------------------------------------------------------------ | -------------- | ------------
|ASSETS                                                                   | 2004           | 2003        
|                                                                        
|                                                                         | (in thousands)
|Property, plant and equipment:                                          
|Domestic utility:                                                       
|Electric plant in service                                                |                | $5,769,017  
|Gas plant in service                                                     |                | 653,912     
|Other plant in service                                                   |                | 539,610     
|Accumulated depreciation                                                 |                | (3,046,010  
|                                                                         |               
|Net plant                                                                |                | 3,916,529   
|Construction work in progress:                                           |               
|Emery generating facility                                                |                | 323,432     
|Other                                                                    |                | 170,978     
|Other, less accumulated depreciation (accum. depr.) of $3,302 and $3,242 |                | 66,858      
|                                                                         |               
|Total domestic utility                                                   |                | 4,477,797   
|                                                                         |               
|Non-regulated and other:                                                 |               
|Non-regulated Generation, less accum. depr. of $4,281 and $3,380         |                | 205,555     
|International, less accum. depr. of $36,799 and $33,708                  |                | 196,967     
|Other Investments, less accum. depr. of $28,850 and $26,179              |                | 61,408      
|Integrated Services, less accum. depr. of $34,628 and $32,903            |                | 59,330      
|Corporate Services and other, less accum. depr. of $29,609 and $25,283   |                | 68,349      
|                                                                         |               
|Total non-regulated and other                                            |                | 591,609     
|                                                                         |               
|                                                                         |                | 5,069,406   
|                                                                         |               
|                                                                        
|Current assets:                                                          |               
|Cash and temporary cash investments                                      |                | 196,432     
|Restricted cash                                                          |                | 8,453       
|Accounts receivable:                                                     |               
|Customer, less allowance for doubtful accounts of $5,302 and $5,522      |                | 168,886     
|Unbilled utility revenues                                                |                | 94,140      
|Other, less allowance for doubtful accounts of $874 and $786             |                | 62,898      
|Income tax refunds receivable                                            |                | 44,237      
|Production fuel, at average cost                                         |                | 46,359      
|Materials and supplies, at average cost                                  |                | 62,236      
|Gas stored underground, at average cost                                  |                | 15,912      
|Regulatory assets                                                        |                | 43,285      
|Other                                                                    |                | 64,624      
|                                                                         |               
|                                                                         |                | 807,462     
|                                                                         |               
|                                                                        
|Investments:                                                             |               
|Investments in unconsolidated foreign entities                           |                | 503,485     
|Nuclear decommissioning trust funds                                      |                | 395,774     
|Investment in ATC and other                                              |                | 267,494     
|                                                                         |               
|                                                                         |                | 1,166,753   
|                                                                         |               
|                                                                        
|Other assets:                                                            |               
|Regulatory assets                                                        |                | 329,742     
|Deferred charges and other                                               |                | 393,525     
|                                                                         |               
|                                                                         |                | 723,267     
|                                                                         |               
|                                                                        
|Total assets                                                             |                | $7,766,888  
|                                                                         |               
|                                                                        

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

3

ALLIANT ENERGY
CORPORATION                               CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED) (Continued)

|                                                                   | March 31,                            | December 31,
|------------------------------------------------------------------ | ------------------------------------ | ------------
|CAPITALIZATION AND LIABILITIES                                     | 2004                                 | 2003        
|                                                                  
|                                                                   | (in thousands, except share amounts)
|Capitalization:                                                    |                                      |             
|Common stock - $0.01 par value - authorized 200,000,000 shares;    |                                     
|outstanding 111,321,380 and 110,962,910 shares                     |                                      | $1,113      
|Additional paid-in capital                                         |                                      | 1,653,113   
|Retained earnings                                                  |                                      | 846,788     
|Accumulated other comprehensive loss                               |                                      | (100,661    
|Shares in deferred compensation trust - 268,485 and 264,673 shares |                                     
|at an average cost of $27.54 and $27.84 per share                  |                                      | (7,395      
|                                                                   |                                     
|Total common equity                                                |                                      | 2,392,958   
|                                                                   |                                     
|                                                                  
|Cumulative preferred stock of subsidiaries, net                    |                                      | 243,803     
|Long-term debt, net (excluding current portion)                    |                                      | 2,104,908   
|                                                                   |                                     
|                                                                   |                                      | 4,741,669   
|                                                                   |                                     
|                                                                  
|Current liabilities:                                               |                                     
|Current maturities and sinking funds                               |                                      | 69,346      
|Variable rate demand bonds                                         |                                      | 55,100      
|Commercial paper                                                   |                                      | 122,500     
|Other short-term borrowings                                        |                                      | 16,717      
|Accounts payable                                                   |                                      | 276,622     
|Accrued interest                                                   |                                      | 45,180      
|Accrued taxes                                                      |                                      | 55,927      
|Other                                                              |                                      | 159,432     
|                                                                   |                                     
|                                                                   |                                      | 800,824     
|                                                                   |                                     
|                                                                  
|Other long-term liabilities and deferred credits:                  |                                     
|Accumulated deferred income taxes                                  |                                      | 719,135     
|Accumulated deferred investment tax credits                        |                                      | 47,817      
|Regulatory liabilities                                             |                                      | 641,648     
|Asset retirement obligations                                       |                                      | 351,491     
|Pension and other benefit obligations                              |                                      | 196,041     
|Other                                                              |                                      | 210,607     
|                                                                   |                                     
|                                                                   |                                      | 2,166,739   
|                                                                   |                                     
|                                                                  
|Minority interest                                                  |                                      | 57,656      
|                                                                   |                                     
|                                                                  
|Total capitalization and liabilities                               |                                      | $7,766,888  
|                                                                   |                                     
|                                                                  

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

4

ALLIANT ENERGY
CORPORATION                     CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(UNAUDITED)

|                                                                                        | For the Three Months Ended March 31,
|--------------------------------------------------------------------------------------- | ------------------------------------
|                                                                                        | 2004                                
|                                                                                       
|                                                                                        | (in thousands)                      
|Cash flows from operating activities:                                                   |                                     
|Net income (loss)                                                                       |                                     
|Adjustments to reconcile net income (loss) to net cash flows from operating activities:
|Loss from discontinued operations, net of tax                                           |                                     
|Depreciation and amortization                                                           |                                     
|Other amortizations                                                                     |                                     
|Deferred tax expense and investment tax credits                                         |                                     
|Equity (income) loss from unconsolidated investments, net                               |                                     
|Distributions from equity method investments                                            |                                     
|Cumulative effect of changes in accounting principles, net of tax                       |                                     
|Other                                                                                   |                                     
|Other changes in assets and liabilities:                                                |                                     
|Accounts receivable                                                                     |                                     
|Sale of utility accounts receivable                                                     |                                     
|Income tax refunds receivable                                                           |                                     
|Gas stored underground                                                                  |                                     
|Accounts payable                                                                        |                                     
|Adjustment clause balances                                                              |                                     
|Other                                                                                   |                                     
|                                                                                        |                                     
|Net cash flows from operating activities                                                |                                     
|                                                                                        |                                     
|                                                                                       
|Cash flows from (used for) financing activities:                                        |                                     
|Common stock dividends                                                                  |                                     
|Proceeds from issuance of common stock                                                  |                                     
|Proceeds from issuance of long-term debt                                                |                                     
|Reductions in long-term debt                                                            |                                     
|Net change in commercial paper and other short-term borrowings                          |                                     
|Net change in loans with discontinued operations                                        |                                     
|Other                                                                                   |                                     
|                                                                                        |                                     
|Net cash flows from (used for) financing activities                                     |                                     
|                                                                                        |                                     
|                                                                                       
|Cash flows used for investing activities:                                               |                                     
|Construction and acquisition expenditures:                                              |                                     
|Domestic utility business                                                               |                                     
|Non-regulated businesses                                                                |                                     
|Corporate Services                                                                      |                                     
|Nuclear decommissioning trust funds                                                     |                                     
|Other                                                                                   |                                     
|                                                                                        |                                     
|Net cash flows used for investing activities                                            |                                     
|                                                                                        |                                     
|                                                                                       
|Net increase (decrease) in cash and temporary cash investments                          |                                     
|                                                                                        |                                     
|                                                                                       
|Cash and temporary cash investments at beginning of period                              |                                     
|                                                                                        |                                     
|                                                                                       
|Cash and temporary cash investments at end of period                                    |                                     
|                                                                                        |                                     
|                                                                                       
|Supplemental cash flows information:                                                    |                                     
|Cash paid (refunded) during the period for:                                             |                                     
|Interest                                                                                |                                     
|                                                                                        |                                     
|Income taxes, net of refunds                                                            |                                     
|                                                                                        |                                     
|Noncash investing and financing activities:                                             |                                     
|Capital lease obligations incurred                                                      |                                     
|                                                                                        |                                     
|                                                                                       

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

5

# ALLIANT ENERGY
CORPORATIONNOTES TO CONDENSED
CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

|1. |  | The
interim condensed consolidated financial statements included herein have           been
prepared by Alliant Energy, without audit, pursuant to the rules and
          regulations of the SEC. Accordingly, certain information and footnote
          disclosures normally included in financial statements prepared in accordance
          with GAAP have been condensed or omitted, although management believes that the
          disclosures are adequate to make the information presented not misleading. The
          condensed consolidated financial statements include Alliant Energy and its
          consolidated subsidiaries (including IP&L, WP&L, Resources and
Corporate           Services). These financial statements should be read in conjunction
with the           financial statements and the notes thereto included in Alliant Energys,
          IP&Ls and WP&Ls latest combined Annual Report on Form 10-K.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | In
the opinion of management, all adjustments, which are normal and recurring in nature,
necessary for a fair presentation of (a) the consolidated results of operations for the
three months ended March 31, 2004 and 2003, (b) the consolidated financial position at
March 31, 2004 and Dec. 31, 2003, and (c) the consolidated statement of cash flows for the
three months ended March 31, 2004 and 2003, have been made. Because of the seasonal nature
of Alliant Energys utility operations, results for the three months ended March 31,
2004 are not necessarily indicative of results that may be expected for the year ending
Dec. 31, 2004. Certain prior period amounts have been reclassified on a basis consistent
with the current period presentation.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|2. |  | Alliant
Energys comprehensive income, and the components of other           comprehensive
income, net of taxes, for the three months ended March 31 were as           follows (in
thousands):
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                                                 | 2004 | 2003   
|---------------------------------------------------------------- | ---- | -------
|                                                                 |     
|Net income (loss)                                                |      | $34,067
|Unrealized holding gains (losses) on securities, net of tax      |      | 3,925  
|Less:  reclassification adjustment for gains                     |     
|included in net income (loss), net of tax                        |      | 3      
|                                                                 |     
|Net unrealized gains (losses) on securities                      |      | 3,922  
|                                                                 |     
|Foreign currency translation adjustments, net of tax             |      | 1,714  
|                                                                 |     
|Unrealized holding gains (losses) on qualifying derivatives, net |     
|of tax                                                           |      | 51     
|Less:  reclassification adjustment for losses                    |     
|included in net income (loss), net of tax                        |      | (67    
|                                                                 |     
|Net unrealized gains (losses) on qualifying derivatives          |      | 118    
|                                                                 |     
|Other comprehensive income                                       |      | 5,754  
|                                                                 |     
|Comprehensive income                                             |      | $39,821
|                                                                 |     

|3. |  | Certain
financial information relating to Alliant Energys significant           business
segments is as follows. Intersegment revenues were not material to           Alliant
Energys operations.
|-- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                                            | Domestic Utility Business | Non-regulated Businesses |        | Alliant 
|----------------------------------------------------------- | ------------------------- | ------------------------ | ------ | --------
|                                                            |                           |                          | Energy
|                                                            | Electric                  | Gas                      | Other  | Total   
|                                                            |                          
|                                                            | (in thousands)           
|Three Months Ended March 31, 2004                           |                           |                          |        |         
|Operating revenues                                          |                           | $467,906                 |        | $248,869
|Operating income (loss)                                     |                           | 46,399                   |        | 27,395  
|Net income (loss)                                           |                           |                          | 33,361 |         
|                                                           
|Three Months Ended March 31, 2003                           |                          
|Operating revenues                                          |                           | $443,025                 |        | $257,881
|Operating income (loss)                                     |                           | 38,190                   |        | 35,376  
|Income (loss) from continuing                               |                          
|operations                                                  |                           |                          | 30,971 |         
|Income (loss) from discontinued                             |                          
|operations, net of tax                                      |                           |                          | --     |         
|Cumulative effect of changes in                             |                          
|accounting principles, net of tax                           |                           |                          | --     |         
|Net income (loss)                                           |                           |                          | 30,971 |         
|                                                           
|* Int'l = International       ** ISCO = Integrated Services

6

|4. |  | The
provisions for income taxes for earnings from continuing operations are           based
on the estimated annual effective tax rate, which differs from the federal
          statutory rate of 35% principally due to state income taxes, the impact of
          foreign income and associated taxes, tax credits, effects of utility rate
making           and certain non-deductible expenses.
|-- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|5. |  | Alliant
Energy utilizes derivative instruments to manage its exposures to           various
market risks as described in Alliant Energys, IP&Ls and           WP&Ls
combined Annual Report on Form 10-K for the year ended Dec. 31,           2003. The
following information supplements, and should be read in conjunction           with, Note
10(a) in Alliant Energys Notes to Consolidated Financial           Statements in
the Form 10-K for the year ended Dec. 31, 2003.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | For
the three months ended March 31, 2004, no income or loss was recognized in connection with
hedge ineffectiveness in accordance with SFAS 133, Accounting for Derivative
Instruments and Hedging Activities and Alliant Energy reclassified a loss of $0.1
million into earnings as a result of the discontinuance of hedges. At March 31, 2004, the
maximum length of time over which Alliant Energy hedged its exposure to the variability in
future cash flows for forecasted transactions was five months and Alliant Energy estimates
that income of $0.4 million will be reclassified from accumulated other comprehensive loss
into earnings within the 12 months between April 1, 2004 and March 31, 2005 as the hedged
transactions affect earnings.
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|6. |  | A
reconciliation of the weighted average common shares outstanding used in the
          basic and diluted EPS calculation for the three months ended March 31 was as
          follows:
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                            | 2004        | 2003      
|------------------------------------------- | ----------- | ----------
|                                            |            
|Weighted average common shares outstanding: |             |           
|Basic EPS calculation                       | 111,153,173 | 92,511,062
|Effect of dilutive securities               | 425,781     | 27,312    
|                                            |            
|Diluted EPS calculation                     | 111,578,954 | 92,538,374
|                                            |            

| | The
following options to purchase shares of common stock were excluded from the calculation of
diluted EPS as the exercise prices were greater than the average market price for the
three months ended March 31 as follows:
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                           | 2004      | 2003     
|------------------------------------------ | --------- | ---------
|                                           |          
|Options to purchase shares of common stock | 3,401,588 | 4,799,336
|Average exercise price of options excluded | $29.34    | $26.95   

| | The
effect on net income (loss) and EPS for the three months ended March 31 if Alliant Energy
had applied the fair value recognition provisions of SFAS 123, Accounting for
Stock-Based Compensation, to the stock options issued under its two stock-based
incentive compensation plans was as follows (dollars in thousands):
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                                    | 2004 | 2003   
|--------------------------------------------------- | ---- | -------
|                                                    |     
|Net income (loss), as reported                      |      | $34,067
|Less:  stock-based compensation expense, net of tax |      | 441    
|                                                    |     
|Pro forma net income (loss)                         |      | $33,626
|                                                    |     
|                                                   
|EPS (basic and diluted):                            |     
|As reported                                         |      | $0.31  
|Pro forma                                           |      | $0.30  

|7. |  | Alliant
Energy completed the sale of its Australian, affordable housing and
          SmartEnergy, Inc. businesses in the second, third and third quarters of 2003,
          respectively. In the fourth quarter of 2003, Alliant Energy completed an
initial           public offering of WPC, leaving Alliant Energy with an approximate 6%
ownership           interest in WPC that is accounted for under the cost method as of
March 31,           2004. The operating results for these non-regulated businesses for
the three           months ended March 31, 2003 have been separately classified and
reported as           discontinued operations in Alliant Energys Condensed
Consolidated           Financial Statements.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

7

| | A
summary of the components of discontinued operations in Alliant Energys Condensed
Consolidated Statement of Income for the three months ended March 31, 2003 was as follows
(in thousands):
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|Operating revenues                            |  | $66,909 |  
|--------------------------------------------- |  | ------- | -
|Operating expenses                            |  | 41,987  |  
|Interest expense and other                    |  | 31,493  |  
|                                              | 
|Loss before income taxes                      |  | (6,571  | )
|Income taxes                                  |  | 2,563   |  
|                                              | 
|Loss from discontinued operations, net of tax |  | ($9,134 | )
|                                              | 

| | Interest
expense and other in the first quarter of 2003 included pre-tax valuation
adjustments of approximately $35 million to reflect updated estimates of the market value,
less selling costs, of the $1 billion of assets classified as assets held for sale as of
March 31, 2003.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | A
summary of the components of cash flows for discontinued operations for the three months
ended March 31, 2003 was as follows (in thousands):
| | ----------------------------------------------------------------------------------------------------------------------------------------------

|Net cash flows from operating activities                   |  | $9,932  |  
|---------------------------------------------------------- |  | ------- | -
|Net cash flows from financing activities                   |  | 8,987   |  
|Net cash flows used for investing activities               |  | (2,554  | )
|                                                           | 
|Net increase in cash and temporary cash investments        |  | 16,365  |  
|Cash and temporary cash investments at beginning of period |  | 16,043  |  
|                                                           | 
|Cash and temporary cash investments at end of period       |  | $32,408 |  
|                                                           | 
|Supplemental cash flows information:                       | 
|Cash paid during the period for:                           | 
|Interest                                                   |  | $7,071  |  
|                                                           | 
|Income taxes, net of refunds                               |  | $2,498  |  
|                                                           | 

|8. |  | As
of March 31, 2004, Alliant Energy adopted revised FIN 46 guidance (FIN 46R).
          The entities that Alliant Energy consolidated as a result of this guidance did
          not have a material impact on its financial condition or results of operations.
          Upon adoption of FIN 46R, Alliant Energy evaluated all tolling and
          purchased-power agreements it has with entities that own a single power plant.
          After making an exhaustive effort, Alliant Energy concluded that for two of
          these arrangements, the Riverside and RockGen plants, it is unable to obtain
the           information necessary from the counterparty to these agreements to
determine           whether the entity is a variable interest entity and if Alliant
Energy is the           primary beneficiary. These entities consist of power plants that
can sell some           or all of their output to Alliant Energys utility
subsidiaries. The output           is purchased at a variable price which correlates with
some of the major           operating costs of the plant. As a result, Alliant Energys
utility           subsidiaries assume some of the variability inherent in the operation
of these           plants. The utility subsidiaries have not incurred costs related to
the           Riverside contract as of March 31, 2004 as the plant is not expected to be
          operational until the second quarter of 2004. WP&L has incurred costs
          related to the RockGen contract of approximately $17 million and $12 million
for           the quarters ended March 31, 2004 and 2003, respectively. Alliant Energys
          maximum exposure to loss from these contracts is undeterminable due to the
          inability to obtain the necessary information to complete such evaluation.
|-- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|9. |  | Pursuant
to SFAS 143, a reconciliation of the changes in asset retirement           obligations
associated with long-lived assets is as follows (in millions):
|-- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------

|                          | IP&L | WP&L | Total
|------------------------- | ---- | ---- | -----
|                          |     
|Balance at Jan. 1, 2004   |      | $158 |      
|Accretion expense         |      | 3    |      
|                          |     
|Balance at March 31, 2004 |      | $161 |      
|                          |     

8

|10. |  | The
components of Alliant Energys qualified and non-qualified pension
          benefits and other postretirement benefits costs for the three months ended
          March 31 were as follows (in thousands):
|--- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                               | Pension Benefits | Other Postretirement Benefits
|------------------------------ | ---------------- | -----------------------------
|                               |                 
|                               | 2004             | 2003                         
|                               |                 
|Service cost                   |                  | $4,740                       
|Interest cost                  |                  | 10,952                       
|Expected return on plan assets |                  | (11,581                      
|Amortization of:               |                 
|Transition obligation (asset)  |                  | (78                          
|Prior service cost             |                  | 704                          
|Actuarial loss                 |                  | 2,090                        
|                               |                 
|                               |                  | $6,827                       
|                               |                 

| | Alliant
Energy estimates that funding for the pension and postretirement benefit plans for 2004
will be approximately $60 million and $16 million, respectively.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------

|11. |  | In
March 2004, WP&L discontinued its participation in the combined utility
          customer accounts receivable sale program, which is not expected to have a
          negative effect on its liquidity. WP&L had no receivables sold and no
          short-term debt outstanding at the time it discontinued its participation in
the           program. At March 31, 2004 and Dec. 31, 2003, Alliant Energy had sold $101
          million (all at IP&L) and $176 million ($126 million at IP&L and $50
          million at WP&L) of domestic utility customer accounts receivable,
          respectively.
|--- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|12. |  | WP&L
has signed a definitive agreement to sell its 41% ownership interest in
          Kewaunee to a subsidiary of Dominion Resources, Inc. (Dominion). Pending
various           regulatory approvals, including PSCW and Nuclear Regulatory Commission,
the           transaction is expected to be completed in 2004. Approval has already been
          obtained from the Federal Trade Commission, IUB and MPUC, and certain approvals
          have been obtained from the Federal Energy Regulatory Commission.
|--- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | WP&L
anticipates that it will receive approximately $90 million in cash and retain ownership of
the trust assets contained in one of the two decommissioning funds it has established to
cover the eventual decommissioning of Kewaunee. The fund that will be retained had an
after-tax value of $69 million on March 31, 2004. Dominion will assume responsibility for
the eventual decommissioning of Kewaunee and will receive WP&Ls qualified
decommissioning trust assets which had an after-tax value of $172 million on March 31,
2004. The gross cash proceeds from the sale are expected to slightly exceed
WP&Ls carrying value of the assets being sold. WP&L has requested deferral
of any gain and related costs from the PSCW. Because any gain realized and the retained
decommissioning fund will likely be returned to customers in future rate filings, WP&L
does not expect this transaction will have a significant impact on its operating results.
As of March 31, 2004, WP&Ls share of the carrying value of the assets and
liabilities included within the sale agreement were as follows (amounts in millions):
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|Investments                        |  | $172 |  | Asset retirement obligations |  | $190 |  
|---------------------------------- |  | ---- |  | ---------------------------- |  | ---- | -
|Property, plant and equipment, net |  | 78   |  | Regulatory liabilities       |  | (4   | )
|Other                              |  | 9    | 
|                                   |  |      | 
|Total assets                       |  | $259 |  | Total liabilities            |  | $186 |  
|                                   |  |      | 

| | The
assets and liabilities above do not meet the criteria to be classified as held for sale on
the Condensed Consolidated Balance Sheets under the provisions of SFAS 144,
Accounting for the Impairment or Disposal of Long-Lived Assets, due to the
uncertainties inherent in the regulatory process. At the closing of the sale, WP&L
will enter into a long-term purchased-power agreement with Dominion to purchase energy and
capacity equivalent to the amounts received had current ownership continued. The
purchased-power agreement, which also will require regulatory approval, will extend
through 2013 when Kewaunees current operating license will expire. In April 2004,
WP&L entered into an exclusivity agreement with Dominion. Under this agreement, if
Dominion decides to extend the operating license of Kewaunee, Dominion agreed to negotiate
only with WP&L and Wisconsin Public Service Corporation for new purchased-power
agreements for their respective share of the plant output that would extend beyond
Kewaunees current operating license termination date. The exclusivity period will
start on the closing date of the sale and will extend through Dec. 21, 2011.
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|13. |  | Alliant
Energy has fully and unconditionally guaranteed the payment of principal           and
interest on various debt securities issued by Resources and, as a result, is
          required to present condensed consolidating financial statements. No Alliant
          Energy subsidiaries are guarantors of Resources debt securities. Alliant
          Energys condensed consolidating financial statements are as follows:
|--- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

9

Alliant Energy
Corporation Condensed Consolidating Statements of Income for the Three Months Ended March
31, 2004 and 2003

|                                                                  | Alliant Energy |           | Other Alliant |               | Consolidated
|----------------------------------------------------------------- | -------------- | --------- | ------------- | ------------- | ------------
|                                                                  | Parent         |           | Energy        | Consolidating | Alliant     
|                                                                  | Company        | Resources | Subsidiaries  | Adjustments   | Energy      
|                                                                  |               
|Three Months Ended March 31, 2004                                 | (in thousands)
|Operating revenues:                                               |                |           |               |               |             
|Domestic utility:                                                 |               
|Electric                                                          |                | $-        |               | $-            |             
|Gas                                                               |                | -         |               | -             |             
|Other                                                             |                | -         |               | -             |             
|Non-regulated                                                     |                | -         |               | 156,089       |             
|                                                                  |               
|                                                                  |                | -         |               | 156,089       |             
|                                                                  |               
|Operating expenses:                                               |               
|Domestic utility:                                                 |               
|Electric production fuel and purchased power                      |                | -         |               | -             |             
|Cost of gas sold                                                  |                | -         |               | -             |             
|Other operation and maintenance                                   |                | -         |               | -             |             
|Non-regulated operation and maintenance                           |                | 331       |               | 140,337       |             
|Depreciation and amortization                                     |                | 13        |               | 8,853         |             
|Taxes other than income taxes                                     |                | (1        | )             | 2,104         |             
|                                                                  |               
|                                                                  |                | 343       |               | 151,294       |             
|                                                                  |               
|Operating income (loss)                                           |                | (343      | )             | 4,795         |             
|                                                                  |               
|Interest expense and other:                                       |               
|Interest expense                                                  |                | 200       |               | 19,398        |             
|Loss on early extinguishment of debt                              |                | -         |               | 5,392         |             
|Equity income from unconsolidated investments                     |                | -         |               | (11,948       | )           
|Allowance for funds used during construction                      |                | -         |               | -             |             
|Preferred dividend requirements of subsidiaries                   |                | -         |               | -             |             
|Interest income and other                                         |                | (37,399   | )             | 457           |             
|                                                                  |               
|                                                                  |                | (37,199   | )             | 13,299        |             
|                                                                  |               
|Income (loss) before income taxes                                 |                | 36,856    |               | (8,504        | )           
|                                                                  |               
|Income tax expense (benefit)                                      |                | 2,789     |               | (12,423       | )           
|                                                                  |               
|Net income                                                        |                | $34,067   |               | $3,919        |             
|                                                                  |               
|Three Months Ended March 31, 2003                                 |               
|Operating revenues:                                               |               
|Domestic utility:                                                 |               
|Electric                                                          |                | $-        |               | $-            |             
|Gas                                                               |                | -         |               | -             |             
|Other                                                             |                | -         |               | -             |             
|Non-regulated                                                     |                | -         |               | 185,553       |             
|                                                                  |               
|                                                                  |                | -         |               | 185,553       |             
|                                                                  |               
|Operating expenses:                                               |               
|Domestic utility:                                                 |               
|Electric production fuel and purchased power                      |                | -         |               | -             |             
|Cost of gas sold                                                  |                | -         |               | -             |             
|Other operation and maintenance                                   |                | -         |               | -             |             
|Non-regulated operation and maintenance                           |                | 312       |               | 171,429       |             
|Depreciation and amortization                                     |                | 8         |               | 8,119         |             
|Taxes other than income taxes                                     |                | 3         |               | 1,729         |             
|                                                                  |               
|                                                                  |                | 323       |               | 181,277       |             
|                                                                  |               
|Operating income (loss)                                           |                | (323      | )             | 4,276         |             
|                                                                  |               
|Interest expense and other:                                       |               
|Interest expense                                                  |                | 3,900     |               | 26,850        |             
|Equity (income) loss from unconsolidated investments              |                | -         |               | 8,475         |             
|Allowance for funds used during construction                      |                | -         |               | -             |             
|Preferred dividend requirements of subsidiaries                   |                | -         |               | -             |             
|Interest income and other                                         |                | (7,910    | )             | (4,496        | )           
|                                                                  |               
|                                                                  |                | (4,010    | )             | 30,829        |             
|                                                                  |               
|Income (loss) from continuing operations before income taxes      |                | 3,687     |               | (26,553       | )           
|                                                                  |               
|Income tax expense (benefit)                                      |                | 4,165     |               | (15,882       | )           
|                                                                  |               
|Income (loss) from continuing operations                          |                | (478      | )             | (10,671       | )           
|                                                                  |               
|Loss from discontinued operations, net of tax                     |                | -         |               | (9,134        | )           
|                                                                  |               
|Income (loss) before cumulative effect of changes in              |               
|accounting principles                                             |                | (478      | )             | (19,805       | )           
|                                                                  |               
|Cumulative effect of changes in accounting principles, net of tax |                | -         |               | (5,983        | )           
|                                                                  |               
|Net income (loss)                                                 |                | ($478     | )             | ($25,788      | )           
|                                                                  |               

10

Alliant Energy
Corporation Condensed Consolidating Balance Sheet as of March 31, 2004

|                                                 | Alliant Energy |            | Other          |               | Consolidated
|------------------------------------------------ | -------------- | ---------- | -------------- | ------------- | ------------
|                                                 | Parent         |            | Alliant Energy | Consolidating | Alliant     
|ASSETS                                           | Company        | Resources  | Subsidiaries   | Adjustments   | Energy      
|                                                 |               
|Property, plant and equipment:                   | (in thousands)
|Domestic utility:                               
|Electric plant in service                        |                | $-         |                | $-            |             
|Other plant in service                           |                | -          |                | -             |             
|Accumulated depreciation                         |                | -          |                | -             |             
|Construction work in progress                    |                | -          |                | -             |             
|Other, net                                       |                | -          |                | -             |             
|                                                 |               
|Total domestic utility                           |                | -          |                | -             |             
|                                                 |               
|Non-regulated and other, net                     |                | -          |                | 523,037       |             
|                                                 |               
|                                                 |                | -          |                | 523,037       |             
|                                                 |               
|Current assets:                                  |               
|Restricted cash                                  |                | -          |                | 5,403         |             
|Accounts receivable, net                         |                | 7,718      |                | 99,492        |             
|Income tax refunds receivable                    |                | 32,111     |                | 22,833        |             
|Gas stored underground, at average cost          |                | -          |                | 63            |             
|Regulatory assets                                |                | -          |                | -             |             
|Other                                            |                | 48,565     |                | 128,736       |             
|                                                 |               
|                                                 |                | 88,394     |                | 256,527       |             
|                                                 |               
|Investments:                                     |               
|Consolidated subsidiaries                        |                | 2,320,579  |                | -             |             
|Other                                            |                | 12,592     |                | 594,870       |             
|                                                 |               
|                                                 |                | 2,333,171  |                | 594,870       |             
|                                                 |               
|                                                 |               
|Deferred charges and other                       |                | 5,664      |                | 173,240       |             
|                                                 |               
|Total assets                                     |                | $2,427,229 |                | $1,547,674    |             
|                                                 |               
|CAPITALIZATION AND LIABILITIES                   |               
|Capitalization:                                  |               
|Common stock and additional paid-in capital      |                | $1,654,226 |                | $232,878      |             
|Retained earnings                                |                | 846,788    |                | 116,922       |             
|Accumulated other comprehensive loss             |                | (100,661   | )              | (63,348       | )           
|Shares in deferred compensation trust            |                | (7,395     | )              | -             |             
|                                                 |               
|Total common equity                              |                | 2,392,958  |                | 286,452       |             
|                                                 |               
|Cumulative preferred stock of subsidiaries, net  |                | -          |                | -             |             
|Long-term debt, net (excluding current portion)  |                | -          |                | 855,590       |             
|                                                 |               
|                                                 |                | 2,392,958  |                | 1,142,042     |             
|                                                 |               
|                                                 |               
|Current liabilities                              |                | 34,323     |                | 167,705       |             
|                                                 |               
|                                                 |               
|Other long-term liabilities and deferred credits |                | (52        | )              | 180,271       |             
|                                                 |               
|                                                 |               
|Minority interest                                |                | -          |                | 57,656        |             
|                                                 |               
|Total capitalization and liabilities             |                | $2,427,229 |                | $1,547,674    |             
|                                                 |               

11

Alliant Energy
Corporation Condensed Consolidating Balance Sheet as of December 31, 2003

|                                                 | Alliant Energy |            | Other          |               | Consolidated
|------------------------------------------------ | -------------- | ---------- | -------------- | ------------- | ------------
|                                                 | Parent         |            | Alliant Energy | Consolidating | Alliant     
|ASSETS                                           | Company        | Resources  | Subsidiaries   | Adjustments   | Energy      
|                                                 |               
|Property, plant and equipment:                   | (in thousands)
|Domestic utility:                               
|Electric plant in service                        |                | $-         |                | $-            |             
|Other plant in service                           |                | -          |                | -             |             
|Accumulated depreciation                         |                | -          |                | -             |             
|Construction work in progress                    |                | -          |                | -             |             
|Other, net                                       |                | -          |                | -             |             
|                                                 |               
|Total domestic utility                           |                | -          |                | -             |             
|                                                 |               
|Non-regulated and other, net                     |                | -          |                | 517,598       |             
|                                                 |               
|                                                 |                | -          |                | 517,598       |             
|                                                 |               
|Current assets:                                  |               
|Restricted cash                                  |                | -          |                | 8,401         |             
|Accounts receivable, net                         |                | 6,581      |                | 90,442        |             
|Income tax refunds receivable                    |                | 9,127      |                | 7,122         |             
|Gas stored underground, at average cost          |                | -          |                | 41,666        |             
|Regulatory assets                                |                | -          |                | -             |             
|Other                                            |                | 40,232     |                | 185,392       |             
|                                                 |               
|                                                 |                | 55,940     |                | 333,023       |             
|                                                 |               
|Investments:                                     |               
|Consolidated subsidiaries                        |                | 2,324,030  |                | -             |             
|Other                                            |                | 12,422     |                | 567,965       |             
|                                                 |               
|                                                 |                | 2,336,452  |                | 567,965       |             
|                                                 |               
|                                                 |               
|Deferred charges and other                       |                | 4,146      |                | 174,614       |             
|                                                 |               
|Total assets                                     |                | $2,396,538 |                | $1,593,200    |             
|                                                 |               
|CAPITALIZATION AND LIABILITIES                   |               
|Capitalization:                                  |               
|Common stock and additional paid-in capital      |                | $1,644,682 |                | $232,743      |             
|Retained earnings                                |                | 840,417    |                | 113,004       |             
|Accumulated other comprehensive loss             |                | (106,415   | )              | (69,102       | )           
|Shares in deferred compensation trust            |                | (7,370     | )              | -             |             
|                                                 |               
|Total common equity                              |                | 2,371,314  |                | 276,645       |             
|                                                 |               
|Cumulative preferred stock of subsidiaries, net  |                | -          |                | -             |             
|Long-term debt, net (excluding current portion)  |                | -          |                | 874,079       |             
|                                                 |               
|                                                 |                | 2,371,314  |                | 1,150,724     |             
|                                                 |               
|                                                 |               
|Current liabilities                              |                | 22,049     |                | 218,068       |             
|                                                 |               
|                                                 |               
|Other long-term liabilities and deferred credits |                | 3,175      |                | 171,866       |             
|                                                 |               
|                                                 |               
|Minority interest                                |                | -          |                | 52,542        |             
|                                                 |               
|Total capitalization and liabilities             |                | $2,396,538 |                | $1,593,200    |             
|                                                 |               

12

Alliant Energy
Corporation Condensed Consolidating Statements of Cash Flows for the Three Months Ended
March 31, 2004 and 2003

|                                                               | Alliant Energy |           | Other Alliant |               | Consolidated
|-------------------------------------------------------------- | -------------- | --------- | ------------- | ------------- | ------------
|                                                               | Parent         |           | Energy        | Consolidating | Alliant     
|                                                               | Company        | Resources | Subsidiaries  | Adjustments   | Energy      
|                                                               |               
|Three Months Ended March 31, 2004                              | (in thousands)
|                                                              
|Net cash flows from (used for) operating activities            |                | $22,069   |               | ($8,599       | )           
|                                                               |               
|Cash flows used for financing activities:                      |               
|Common stock dividends                                         |                | (27,696   | )             | -             |             
|Reductions in long-term debt                                   |                | -         |               | (20,895       | )           
|Net change in commercial paper and other short-term borrowings |                | (12,712   | )             | (5,027        | )           
|Other                                                          |                | 7,630     |               | 3,036         |             
|                                                               |               
|Net cash flows used for financing activities                   |                | (32,778   | )             | (22,886       | )           
|                                                               |               
|Cash flows from (used for) investing activities:               |               
|Construction and acquisition expenditures:                     |               
|Domestic utility business                                      |                | -         |               | -             |             
|Non-regulated businesses                                       |                | -         |               | (15,842       | )           
|Corporate Services                                             |                | -         |               | -             |             
|Other                                                          |                | 9,437     |               | 993           |             
|                                                               |               
|Net cash flows from (used for) investing activities            |                | 9,437     |               | (14,849       | )           
|                                                               |               
|Net increase (decrease) in cash and temporary cash investments |                | (1,272    | )             | (46,334       | )           
|                                                               |               
|Cash and temporary cash investments at beginning of period     |                | 35,776    |               | 144,361       |             
|                                                               |               
|Cash and temporary cash investments at end of period           |                | $34,504   |               | $98,027       |             
|                                                               |               
|Supplemental cash flows information:                           |               
|Cash paid (refunded) during the period for:                    |               
|Interest                                                       |                | $164      |               | $17,942       |             
|                                                               |               
|Income taxes, net of refunds                                   |                | $1,273    |               | $25,569       |             
|                                                               |               
|Noncash investing and financing activities:                    |               
|Capital lease obligations incurred                             |                | $-        |               | $-            |             
|                                                               |               
|Three Months Ended March 31, 2003                              |               
|                                                              
|Net cash flows from (used for) operating activities            |                | ($1,864   | )             | ($20,575      | )           
|                                                               |               
|Cash flows from (used for) financing activities:               |               
|Common stock dividends                                         |                | (23,033   | )             | -             |             
|Proceeds from issuance of long-term debt                       |                | -         |               | 60,000        |             
|Reductions in long-term debt                                   |                | -         |               | (670          | )           
|Net change in commercial paper and other short-term borrowings |                | (9,729    | )             | 65,040        |             
|Net change in loans with discontinued operations               |                | -         |               | (17,501       | )           
|Other                                                          |                | 5,143     |               | (3,018        | )           
|                                                               |               
|Net cash flows from (used for) financing activities            |                | (27,619   | )             | 103,851       |             
|                                                               |               
|Cash flows from (used for) investing activities:               |               
|Construction and acquisition expenditures:                     |               
|Domestic utility business                                      |                | -         |               | -             |             
|Non-regulated businesses                                       |                | -         |               | (180,286      | )           
|Corporate Services                                             |                | -         |               | -             |             
|Other                                                          |                | 31,801    |               | 107,657       |             
|                                                               |               
|Net cash flows from (used for) investing activities            |                | 31,801    |               | (72,629       | )           
|                                                               |               
|Net increase (decrease) in cash and temporary cash investments |                | 2,318     |               | 10,647        |             
|                                                               |               
|Cash and temporary cash investments at beginning of period     |                | 4         |               | 47,236        |             
|                                                               |               
|Cash and temporary cash investments at end of period           |                | $2,322    |               | $57,883       |             
|                                                               |               
|Supplemental cash flows information:                           |               
|Cash paid (refunded) during the period for:                    |               
|Interest                                                       |                | $3,223    |               | $9,621        |             
|                                                               |               
|Income taxes, net of refunds                                   |                | ($3,902   | )             | ($7,278       | )           
|                                                               |               
|Noncash investing and financing activities:                    |               
|Capital lease obligations incurred                             |                | $-        |               | $-            |             
|                                                               |               

13

INTERSTATE POWER AND
LIGHT COMPANY                     CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

|                                             | For the Three Months Ended March 31,
|-------------------------------------------- | ------------------------------------
|                                             | 2004                                
|                                            
|                                             | (in thousands)                      
|Operating revenues:                          |                                     
|Electric utility                             |                                     
|Gas utility                                  |                                     
|Steam and other                              |                                     
|                                             |                                     
|                                             |                                     
|                                             |                                     
|                                            
|Operating expenses:                          |                                     
|Electric production fuel and purchased power |                                     
|Cost of gas sold                             |                                     
|Other operation and maintenance              |                                     
|Depreciation and amortization                |                                     
|Taxes other than income taxes                |                                     
|                                             |                                     
|                                             |                                     
|                                             |                                     
|                                            
|Operating income                             |                                     
|                                             |                                     
|                                            
|Interest expense and other:                  |                                     
|Interest expense                             |                                     
|Allowance for funds used during construction |                                     
|Interest income and other                    |                                     
|                                             |                                     
|                                             |                                     
|                                             |                                     
|                                            
|Income before income taxes                   |                                     
|                                             |                                     
|                                            
|Income taxes                                 |                                     
|                                             |                                     
|                                            
|Net income                                   |                                     
|                                             |                                     
|                                            
|Preferred dividend requirements              |                                     
|                                             |                                     
|                                            
|Earnings available for common stock          |                                     
|                                             |                                     
|                                            

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

14

INTERSTATE POWER AND
LIGHT COMPANY                                    CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED)

|                                                                    | March 31,      | December 31,
|------------------------------------------------------------------- | -------------- | ------------
|ASSETS                                                              | 2004           | 2003        
|                                                                   
|                                                                    | (in thousands)
|Property, plant and equipment:                                      |                |             
|Electric plant in service                                           |                | $3,745,718  
|Gas plant in service                                                |                | 348,280     
|Steam plant in service                                              |                | 60,184      
|Other plant in service                                              |                | 204,929     
|Accumulated depreciation                                            |                | (1,883,456  
|                                                                    |               
|Net plant                                                           |                | 2,475,655   
|Construction work in progress:                                      |               
|Emery generating facility                                           |                | 323,432     
|Other                                                               |                | 96,949      
|Other, less accumulated depreciation of $3,001 and $2,941           |                | 52,065      
|                                                                    |               
|                                                                    |                | 2,948,101   
|                                                                    |               
|                                                                   
|Current assets:                                                     |               
|Cash and temporary cash investments                                 |                | 12,062      
|Accounts receivable:                                                |               
|Customer, less allowance for doubtful accounts of $1,769 and $1,262 |                | 49,079      
|Associated companies                                                |                | 3,625       
|Other, less allowance for doubtful accounts of $541 and $145        |                | 23,519      
|Income tax refunds receivable                                       |                | 15,678      
|Production fuel, at average cost                                    |                | 27,698      
|Materials and supplies, at average cost                             |                | 30,931      
|Gas stored underground, at average cost                             |                | 6,309       
|Regulatory assets                                                   |                | 21,962      
|Prepayments and other                                               |                | 6,644       
|                                                                    |               
|                                                                    |                | 197,507     
|                                                                    |               
|                                                                   
|Investments:                                                        |               
|Nuclear decommissioning trust funds                                 |                | 154,424     
|Other                                                               |                | 14,443      
|                                                                    |               
|                                                                    |                | 168,867     
|                                                                    |               
|                                                                   
|Other assets:                                                       |               
|Regulatory assets                                                   |                | 242,839     
|Deferred charges and other                                          |                | 40,871      
|                                                                    |               
|                                                                    |                | 283,710     
|                                                                    |               
|                                                                   
|Total assets                                                        |                | $3,598,185  
|                                                                    |               
|                                                                   

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

15

INTERSTATE POWER AND
LIGHT COMPANY                              CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED) (Continued)

|                                                               | March 31,                            | December 31,
|-------------------------------------------------------------- | ------------------------------------ | ------------
|CAPITALIZATION AND LIABILITIES                                 | 2004                                 | 2003        
|                                                              
|                                                               | (in thousands, except share amounts)
|Capitalization:                                                |                                      |             
|Common stock - $2.50 par value - authorized 24,000,000 shares; |                                     
|13,370,788 shares outstanding                                  |                                      | $33,427     
|Additional paid-in capital                                     |                                      | 646,169     
|Retained earnings                                              |                                      | 359,793     
|Accumulated other comprehensive loss                           |                                      | (17,078     
|                                                               |                                     
|Total common equity                                            |                                      | 1,022,311   
|                                                               |                                     
|                                                              
|Cumulative preferred stock                                     |                                      | 183,840     
|Long-term debt, net                                            |                                      | 837,878     
|                                                               |                                     
|                                                               |                                      | 2,044,029   
|                                                               |                                     
|                                                              
|Current liabilities:                                           |                                     
|Commercial paper                                               |                                      | 122,500     
|Accounts payable                                               |                                      | 112,428     
|Accounts payable to associated companies                       |                                      | 23,885      
|Accrued taxes                                                  |                                      | 45,067      
|Other                                                          |                                      | 66,613      
|                                                               |                                     
|                                                               |                                      | 370,493     
|                                                               |                                     
|                                                              
|Other long-term liabilities and deferred credits:              |                                     
|Accumulated deferred income taxes                              |                                      | 365,280     
|Accumulated deferred investment tax credits                    |                                      | 26,740      
|Regulatory liabilities                                         |                                      | 410,178     
|Asset retirement obligations                                   |                                      | 160,830     
|Pension and other benefit obligations                          |                                      | 95,767      
|Other                                                          |                                      | 124,868     
|                                                               |                                     
|                                                               |                                      | 1,183,663   
|                                                               |                                     
|                                                              
|Total capitalization and liabilities                           |                                      | $3,598,185  
|                                                               |                                     
|                                                              

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

16

INTERSTATE POWER AND
LIGHT COMPANY                   CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(UNAUDITED)

|                                                               | For the Three Months Ended March 31,
|-------------------------------------------------------------- | ------------------------------------
|                                                               | 2004                                
|                                                              
|                                                               | (in thousands)                      
|Cash flows from operating activities:                          |                                     
|Net income                                                     |                                     
|Adjustments to reconcile net income to net cash                |                                     
|flows from operating activities:                               |                                     
|Depreciation and amortization                                  |                                     
|Amortization of leased nuclear fuel                            |                                     
|Deferred tax expense and investment tax credits                |                                     
|Other                                                          |                                     
|Other changes in assets and liabilities:                       |                                     
|Accounts receivable                                            |                                     
|Sale of accounts receivable                                    |                                     
|Income tax refunds receivable                                  |                                     
|Gas stored underground                                         |                                     
|Accounts payable                                               |                                     
|Accrued taxes                                                  |                                     
|Adjustment clause balances                                     |                                     
|Other                                                          |                                     
|                                                               |                                     
|Net cash flows from operating activities                       |                                     
|                                                               |                                     
|                                                              
|Cash flows from (used for) financing activities:               |                                     
|Common stock dividends                                         |                                     
|Preferred stock dividends                                      |                                     
|Net change in commercial paper                                 |                                     
|Principal payments under capital lease obligations             |                                     
|Other                                                          |                                     
|                                                               |                                     
|Net cash flows from (used for) financing activities            |                                     
|                                                               |                                     
|                                                              
|Cash flows used for investing activities:                      |                                     
|Utility construction expenditures                              |                                     
|Nuclear decommissioning trust funds                            |                                     
|Other                                                          |                                     
|                                                               |                                     
|Net cash flows used for investing activities                   |                                     
|                                                               |                                     
|                                                              
|Net increase (decrease) in cash and temporary cash investments |                                     
|                                                               |                                     
|                                                              
|Cash and temporary cash investments at beginning of period     |                                     
|                                                               |                                     
|                                                              
|Cash and temporary cash investments at end of period           |                                     
|                                                               |                                     
|                                                              
|Supplemental cash flows information:                           |                                     
|Cash paid (refunded) during the period for:                    |                                     
|Interest                                                       |                                     
|                                                               |                                     
|Income taxes, net of refunds                                   |                                     
|                                                               |                                     
|Noncash investing and financing activities:                    |                                     
|Capital lease obligations incurred                             |                                     
|                                                               |                                     
|                                                              

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

17

# INTERSTATE POWER AND
LIGHT COMPANYNOTES TO CONDENSED
CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

| | Except
as modified below, the Alliant Energy Notes to Condensed Consolidated Financial Statements
are incorporated by reference insofar as they relate to IP&L.
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------

|1. |  | The
interim condensed consolidated financial statements included herein have           been
prepared by IP&L, without audit, pursuant to the rules and regulations           of
the SEC. Accordingly, certain information and footnote disclosures normally
          included in financial statements prepared in accordance with GAAP have been
          condensed or omitted, although management believes that the disclosures are
          adequate to make the information presented not misleading. The condensed
          consolidated financial statements include IP&L and its consolidated
          subsidiaries. IP&L is a direct subsidiary of Alliant Energy. These
financial           statements should be read in conjunction with the financial
statements and the           notes thereto included in IP&Ls latest Annual
Report on Form 10-K.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | In
the opinion of management, all adjustments, which are normal and recurring in nature,
necessary for a fair presentation of (a) the consolidated results of operations for the
three months ended March 31, 2004 and 2003, (b) the consolidated financial position at
March 31, 2004 and Dec. 31, 2003, and (c) the consolidated statement of cash flows for the
three months ended March 31, 2004 and 2003, have been made. Because of the seasonal nature
of IP&Ls operations, results for the three months ended March 31, 2004 are not
necessarily indicative of results that may be expected for the year ending Dec. 31, 2004.
Certain prior period amounts have been reclassified on a basis consistent with the current
period presentation.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|2. |  | For
the three months ended March 31, 2004 and 2003, IP&L had no other
          comprehensive income, thus IP&Ls comprehensive income was equal to
its           earnings available for common stock for all periods.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|3. |  | Certain
financial information relating to IP&Ls significant business           segments
is as follows. Intersegment revenues were not material to           IP&Ls
operations.
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                    | Electric       | Gas      | Other  | Total   
|----------------------------------- | -------------- | -------- | ------ | --------
|                                    |               
|                                    | (in thousands)
|Three Months Ended March 31, 2004   |                |          |        |         
|Operating revenues                  |                | $242,282 |        | $137,705
|Operating income                    |                | 23,547   |        | 9,578   
|Earnings available for common stock |                |          | 11,885 |         
|                                   
|Three Months Ended March 31, 2003   |               
|Operating revenues                  |                | $230,329 |        | $126,677
|Operating income                    |                | 38,030   |        | 15,443  
|Earnings available for common stock |                |          | 21,627 |         

|10. |  | The
components of IP&Ls qualified pension benefits and other
          postretirement benefits costs for the three months ended March 31 were as
          follows (in thousands):
|--- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                               | Qualified Pension Benefits | Other Postretirement Benefits
|------------------------------ | -------------------------- | -----------------------------
|                               |                           
|                               | 2004                       | 2003                         
|                               |                           
|Service cost                   |                            | $1,519                       
|Interest cost                  |                            | 3,181                        
|Expected return on plan assets |                            | (3,374                       
|Amortization of:               |                           
|Transition obligation (asset)  |                            | (52                          
|Prior service cost             |                            | 322                          
|Actuarial loss                 |                            | 501                          
|                               |                           
|                               |                            | $2,097                       
|                               |                           

18

| | The
pension benefits costs shown in the previous table represent only the pension benefits
costs for bargaining unit employees of IP&L covered under the bargaining unit pension
plans that are sponsored by IP&L. The pension benefits costs for IP&Ls
non-bargaining employees who are now participants in other Alliant Energy plans was $0.7
million and $1.1 million for the three months ended March 31, 2004 and 2003, respectively.
In addition, Corporate Services provides services to IP&L. The allocated pension
benefits costs associated with these services was $0.9 million and $0.8 million for the
three months ended March 31, 2004 and 2003, respectively. The other postretirement
benefits costs shown previously represent the allocated other postretirement benefits
costs for all IP&L plans. The allocated other postretirement benefits costs associated
with Corporate Services for IP&L was $0.6 million and $0.4 million for the three
months ended March 31, 2004 and 2003, respectively.
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | IP&L
estimates that funding for the qualified pension and postretirement benefit plans for 2004
will be approximately $19 million and $12 million, respectively.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------

19

WISCONSIN POWER AND
LIGHT COMPANY                     CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

|                                              | For the Three Months Ended March 31,
|--------------------------------------------- | ------------------------------------
|                                              | 2004                                
|                                             
|                                              | (in thousands)                      
|Operating revenues:                           |                                     
|Electric utility                              |                                     
|Gas utility                                   |                                     
|Other                                         |                                     
|                                              |                                     
|                                              |                                     
|                                              |                                     
|                                             
|Operating expenses:                           |                                     
|Electric production fuel and purchased power  |                                     
|Cost of gas sold                              |                                     
|Other operation and maintenance               |                                     
|Depreciation and amortization                 |                                     
|Taxes other than income taxes                 |                                     
|                                              |                                     
|                                              |                                     
|                                              |                                     
|                                             
|Operating income                              |                                     
|                                              |                                     
|                                             
|Interest expense and other:                   |                                     
|Interest expense                              |                                     
|Interest income                               |                                     
|Equity income from unconsolidated investments |                                     
|Allowance for funds used during construction  |                                     
|                                              |                                     
|                                              |                                     
|                                              |                                     
|                                             
|Income before income taxes                    |                                     
|                                              |                                     
|                                             
|Income taxes                                  |                                     
|                                              |                                     
|                                             
|Net income                                    |                                     
|                                              |                                     
|                                             
|Preferred dividend requirements               |                                     
|                                              |                                     
|                                             
|Earnings available for common stock           |                                     
|                                              |                                     
|                                             

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

20

WISCONSIN POWER AND
LIGHT COMPANY                                    CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED)

|                                                                    | March 31,      | December 31,
|------------------------------------------------------------------- | -------------- | ------------
|ASSETS                                                              | 2004           | 2003        
|                                                                   
|                                                                    | (in thousands)
|Property, plant and equipment:                                      |                |             
|Electric plant in service                                           |                | $2,023,299  
|Gas plant in service                                                |                | 305,632     
|Other plant in service                                              |                | 274,497     
|Accumulated depreciation                                            |                | (1,162,554  
|                                                                    |               
|Net plant                                                           |                | 1,440,874   
|Construction work in progress                                       |                | 74,029      
|Other, less accumulated depreciation of $301 for both periods       |                | 14,793      
|                                                                    |               
|                                                                    |                | 1,529,696   
|                                                                    |               
|                                                                   
|Current assets:                                                     |               
|Cash and temporary cash investments                                 |                | 15,041      
|Accounts receivable:                                                |               
|Customer, less allowance for doubtful accounts of $2,034 and $2,662 |                | 127,225     
|Other, less allowance for doubtful accounts of $91 and $422         |                | 19,882      
|Income tax refunds receivable                                       |                | 23,264      
|Production fuel, at average cost                                    |                | 14,616      
|Materials and supplies, at average cost                             |                | 24,720      
|Gas stored underground, at average cost                             |                | 9,540       
|Regulatory assets                                                   |                | 21,323      
|Prepaid gross receipts tax                                          |                | 21,256      
|Other                                                               |                | 12,319      
|                                                                    |               
|                                                                    |                | 289,186     
|                                                                    |               
|                                                                   
|Investments:                                                        |               
|Nuclear decommissioning trust funds                                 |                | 241,350     
|Investment in ATC and other                                         |                | 145,716     
|                                                                    |               
|                                                                    |                | 387,066     
|                                                                    |               
|                                                                   
|Other assets:                                                       |               
|Regulatory assets                                                   |                | 86,903      
|Deferred charges and other                                          |                | 181,891     
|                                                                    |               
|                                                                    |                | 268,794     
|                                                                    |               
|                                                                   
|Total assets                                                        |                | $2,474,742  
|                                                                    |               
|                                                                   

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

21

WISCONSIN POWER AND
LIGHT COMPANY                              CONDENSED CONSOLIDATED BALANCE SHEETS
(UNAUDITED) (Continued)

|                                                            | March 31,                            | December 31,
|----------------------------------------------------------- | ------------------------------------ | ------------
|CAPITALIZATION AND LIABILITIES                              | 2004                                 | 2003        
|                                                           
|                                                            | (in thousands, except share amounts)
|Capitalization:                                             |                                      |             
|Common stock - $5 par value - authorized 18,000,000 shares; |                                     
|13,236,601 shares outstanding                               |                                      | $66,183     
|Additional paid-in capital                                  |                                      | 525,635     
|Retained earnings                                           |                                      | 439,518     
|Accumulated other comprehensive loss                        |                                      | (20,235     
|                                                            |                                     
|Total common equity                                         |                                      | 1,011,101   
|                                                            |                                     
|                                                           
|Cumulative preferred stock                                  |                                      | 59,963      
|Long-term debt, net (excluding current portion)             |                                      | 336,440     
|                                                            |                                     
|                                                            |                                      | 1,407,504   
|                                                            |                                     
|                                                           
|Current liabilities:                                        |                                     
|Current maturities                                          |                                      | 62,000      
|Variable rate demand bonds                                  |                                      | 55,100      
|Accounts payable                                            |                                      | 63,019      
|Accounts payable to associated companies                    |                                      | 28,577      
|Accrued taxes                                               |                                      | 14,826      
|Regulatory liabilities                                      |                                      | 13,183      
|Other                                                       |                                      | 29,699      
|                                                            |                                     
|                                                            |                                      | 266,404     
|                                                            |                                     
|                                                           
|Other long-term liabilities and deferred credits:           |                                     
|Accumulated deferred income taxes                           |                                      | 213,859     
|Accumulated deferred investment tax credits                 |                                      | 21,077      
|Regulatory liabilities                                      |                                      | 231,470     
|Asset retirement obligations                                |                                      | 190,661     
|Pension and other benefit obligations                       |                                      | 61,083      
|Other                                                       |                                      | 82,684      
|                                                            |                                     
|                                                            |                                      | 800,834     
|                                                            |                                     
|                                                           
|Total capitalization and liabilities                        |                                      | $2,474,742  
|                                                            |                                     
|                                                           

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

22

WISCONSIN POWER AND
LIGHT COMPANY                   CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(UNAUDITED)

|                                                           | For the Three Months Ended March 31,
|---------------------------------------------------------- | ------------------------------------
|                                                           | 2004                                
|                                                          
|                                                           | (in thousands)                      
|Cash flows from operating activities:                      |                                     
|Net income                                                 |                                     
|Adjustments to reconcile net income to net cash            |                                     
|flows from operating activities:                           |                                     
|Depreciation and amortization                              |                                     
|Amortization of nuclear fuel                               |                                     
|Amortization of deferred energy efficiency expenditures    |                                     
|Deferred tax expense and investment tax credits            |                                     
|Equity income from unconsolidated investments, net         |                                     
|Distributions from equity method investments               |                                     
|Other                                                      |                                     
|Other changes in assets and liabilities:                   |                                     
|Accounts receivable                                        |                                     
|Sale of accounts receivable                                |                                     
|Gas stored underground                                     |                                     
|Prepaid gross receipts tax                                 |                                     
|Accounts payable                                           |                                     
|Accrued taxes                                              |                                     
|Other                                                      |                                     
|                                                           |                                     
|Net cash flows from operating activities                   |                                     
|                                                           |                                     
|                                                          
|Cash flows used for financing activities:                  |                                     
|Common stock dividends                                     |                                     
|Preferred stock dividends                                  |                                     
|Net change in commercial paper                             |                                     
|Other                                                      |                                     
|                                                           |                                     
|Net cash flows used for financing activities               |                                     
|                                                           |                                     
|                                                          
|Cash flows used for investing activities:                  |                                     
|Utility construction expenditures                          |                                     
|Nuclear decommissioning trust funds                        |                                     
|Other                                                      |                                     
|                                                           |                                     
|Net cash flows used for investing activities               |                                     
|                                                           |                                     
|                                                          
|Net decrease in cash and temporary cash investments        |                                     
|                                                           |                                     
|                                                          
|Cash and temporary cash investments at beginning of period |                                     
|                                                           |                                     
|                                                          
|Cash and temporary cash investments at end of period       |                                     
|                                                           |                                     
|                                                          
|Supplemental cash flows information:                       |                                     
|Cash paid during the period for:                           |                                     
|Interest                                                   |                                     
|                                                           |                                     
|Income taxes, net of refunds                               |                                     
|                                                           |                                     
|                                                          

The accompanying Notes to
Condensed Consolidated Financial Statements are an integral part of these statements.

23

# WISCONSIN POWER AND
LIGHT COMPANYNOTES TO CONDENSED
CONSOLIDATED FINANCIAL STATEMENTS (UNAUDITED)

| | Except
as modified below, the Alliant Energy Notes to Condensed Consolidated Financial Statements
are incorporated by reference insofar as they relate to WP&L.
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------

|1. |  | The
interim condensed consolidated financial statements included herein have           been
prepared by WP&L, without audit, pursuant to the rules and regulations           of
the SEC. Accordingly, certain information and footnote disclosures normally
          included in financial statements prepared in accordance with GAAP have been
          condensed or omitted, although management believes that the disclosures are
          adequate to make the information presented not misleading. The condensed
          consolidated financial statements include WP&L and its consolidated
          subsidiaries. WP&L is a direct subsidiary of Alliant Energy. These
financial           statements should be read in conjunction with the financial
statements and the           notes thereto included in WP&Ls latest Annual
Report on Form 10-K.
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | In
the opinion of management, all adjustments, which are normal and recurring in nature,
necessary for a fair presentation of (a) the consolidated results of operations for the
three months ended March 31, 2004 and 2003, (b) the consolidated financial position at
March 31, 2004 and Dec. 31, 2003, and (c) the consolidated statement of cash flows for the
three months ended March 31, 2004 and 2003, have been made. Because of the seasonal nature
of WP&Ls operations, results for the three months ended March 31, 2004 are not
necessarily indicative of results that may be expected for the year ending Dec. 31, 2004.
Certain prior period amounts have been reclassified on a basis consistent with the current
period presentation.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|2. |  | WP&Ls
comprehensive income, and the components of other comprehensive           loss, net of
taxes, for the three months ended March 31 were as follows (in           thousands):
|-- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                                                   | 2004 | 2003   
|------------------------------------------------------------------ | ---- | -------
|                                                                   |     
|Earnings available for common stock                                |      | $21,467
|Unrealized holding losses on qualifying derivatives, net of tax    |      | --     
|Less:  reclassification adjustment for losses included in earnings |     
|available for common stock, net of tax                             |      | --     
|                                                                   |     
|Net unrealized losses on qualifying derivatives                    |      | --     
|                                                                   |     
|Other comprehensive loss                                           |      | --     
|                                                                   |     
|Comprehensive income                                               |      | $21,467
|                                                                   |     

|3. |  | Certain
financial information relating to WP&Ls significant business           segments
is as follows. For the three months ended March 31, 2003, gas revenues           included
$17 million for sales to the electric segment. All other intersegment           revenues
were not material to WP&Ls operations.
|-- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                                    | Electric       | Gas      | Other  | Total   
|----------------------------------- | -------------- | -------- | ------ | --------
|                                    |               
|                                    | (in thousands)
|Three Months Ended March 31, 2004   |                |          |        |         
|Operating revenues                  |                | $225,624 |        | $111,164
|Operating income (loss)             |                | 22,856   |        | 17,817  
|Earnings available for common stock |                |          | 21,467 |         
|                                   
|Three Months Ended March 31, 2003   |               
|Operating revenues                  |                | $212,696 |        | $131,204
|Operating income (loss)             |                | 163      |        | 19,933  
|Earnings available for common stock |                |          | 9,287  |         

24

|10. |  | The
components of WP&Ls qualified pension benefits and other
          postretirement benefits costs for the three months ended March 31 were as
          follows (in thousands):
|--- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|                               | Qualified Pension Benefits | Other Postretirement Benefits
|------------------------------ | -------------------------- | -----------------------------
|                               |                           
|                               | 2004                       | 2003                         
|                               |                           
|Service cost                   |                            | $1,216                       
|Interest cost                  |                            | 2,737                        
|Expected return on plan assets |                            | (3,861                       
|Amortization of:               |                           
|Transition obligation          |                            | --                           
|Prior service cost             |                            | 103                          
|Actuarial loss                 |                            | 830                          
|                               |                           
|                               |                            | $1,025                       
|                               |                           

| | The
pension benefits costs shown in the previous table represent only the pension benefits
costs for bargaining unit employees of WP&L covered under the bargaining unit pension
plan that is sponsored by WP&L. The pension benefits costs for WP&Ls
non-bargaining employees who are now participants in other Alliant Energy plans was $0.1
million and $0.5 million for the three months ended March 31, 2004 and 2003, respectively.
In addition, Corporate Services provides services to WP&L. The allocated pension
benefits costs associated with these services was $0.5 million for both the three months
ended March 31, 2004 and 2003. The other postretirement benefits costs shown previously
represent the allocated other postretirement benefits costs for all WP&L plans. The
allocated other postretirement benefits costs associated with Corporate Services for
WP&L was $0.4 million and $0.3 million for the three months ended March 31, 2004 and
2003, respectively.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | WP&L
estimates that funding for the qualified pension and postretirement benefit plans for 2004
will be $0 and approximately $4 million, respectively.
| | ------------------------------------------------------------------------------------------------------------------------------------------------------

25

|ITEM 2. | MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
|------- | ---------------------------------------------------------------
|        | RESULTS OF OPERATIONS                                          

The primary first tier subsidiaries
of Alliant Energy include: IP&L, WP&L, Resources and Corporate Services. Among
various other regulatory constraints, Alliant Energy is operating as a registered public
utility holding company subject to the limitations imposed by PUHCA. This MD&A
includes information relating to Alliant Energy, IP&L and WP&L (as well as
Resources and Corporate Services). Where appropriate, information relating to a specific
entity has been segregated and labeled as such. The following discussion and analysis
should be read in conjunction with the Condensed Consolidated Financial Statements and
Notes to Condensed Consolidated Financial Statements included in this report as well as
the financial statements, notes and MD&A included in Alliant Energys,
IP&Ls and WP&Ls latest combined Annual Report on Form 10-K.

# FORWARD-LOOKING
STATEMENTS

Statements contained in this report
that are not of historical fact are forward-looking statements intended to qualify for the
safe harbors from liability established by the Private Securities Litigation Reform Act of
1995. Such forward-looking statements are subject to risks and uncertainties that could
cause actual results to differ materially from those expressed in, or implied by, such
statements. Some, but not all, of the risks and uncertainties include: weather effects on
sales and revenues; economic and political conditions in Alliant Energys domestic
and international service territories; federal, state and international regulatory or
governmental actions, including the impact of potential energy-related legislation in
Congress, the ability to obtain adequate and timely rate relief to allow for, among other
things, the recovery of operating costs and the earning of reasonable rates of return in
current and future rate proceedings, including achieving an appropriate level of interim
rates in IP&Ls current Iowa electric case, as well as the payment of expected
levels of dividends; unanticipated construction and acquisition expenditures;
unanticipated issues or delays in connection with Alliant Energys construction of
new generating facilities; issues related to the supply of purchased electricity and price
thereof, including the ability to recover purchased-power and fuel costs in a timely
manner through rates; issues related to electric transmission, including recovery of costs
incurred, and federal legislation and regulation affecting such transmission; risks
related to the operations of Alliant Energys nuclear facilities and unanticipated
issues relating to the pending sale of Alliant Energys interest in Kewaunee; costs
associated with Alliant Energys environmental remediation efforts and with
environmental compliance generally; developments that adversely impact Alliant
Energys ability to implement its strategic plan; the amount of premiums incurred in
connection with Alliant Energys planned debt reductions; improved results from
Alliant Energys Brazil investments in 2004 compared to prior years; improved results
from Alliant Energys other non-regulated businesses as a whole; stable foreign
exchange rates; no material permanent declines in the fair market value of, or expected
cash flows from, Alliant Energys investments; Alliant Energys ability to
continue cost controls and operational efficiencies; Alliant Energys ability to
identify and successfully complete proposed acquisitions and development projects; access
to technological developments; employee workforce factors, including changes in key
executives, collective bargaining agreements or work stoppages; continued access to the
capital markets; the ability to successfully complete ongoing tax audits and appeals with
no material impact on Alliant Energys earnings or cash flows; inflation rates; and
factors listed in Other Matters  Other Future Considerations. Alliant
Energy assumes no obligation, and disclaims any duty, to update the forward-looking
statements in this report.

# STRATEGIC OVERVIEW

Alliant Energys domestic
utility business is its core business and the sole growth platform within its strategic
plan. The strategic plan is concentrated on building and maintaining the generation and
infrastructure necessary to provide Alliant Energys domestic utility customers with
safe, reliable and environmentally sound energy service. Alliant Energys strategic
plan also includes focusing on the profitability and cash flows of its remaining
non-regulated businesses which will serve as ongoing business platforms. The following is
an update related to recent activities of Alliant Energys domestic utility
generation plan announced in December 2003:

- IP&L's 565 MW, combined-cycle, natural gas-fired generating facility (Emery) near Mason City, Iowa is currently being
      tested and is anticipated to be ready for commercial operation in June.
- Calpine Corporation's 600 MW, combined-cycle, natural gas-fired generating facility (Riverside) in Beloit, Wisconsin is
      also currently being tested and is expected to be placed into service this summer.  WP&L has contracted for 453 MW of this
      plant's output.
- Alliant Energy continues to make steady progress related to acquiring regulatory approvals for the 300 MW, simple cycle,
      natural gas-fired generating facility Alliant Energy plans to construct near Sheboygan Falls, Wisconsin that is intended to be
      placed in service in 2005.
- In March 2004, WP&L announced it would accept proposals from bidders for adding 100 MW of wind generation in one or more
      locations in Wisconsin in 2005.  Moving forward with this component of the generation plan is contingent upon a renewal of the
      federal renewable energy production tax credit.

26

# RATES AND REGULATORY
MATTERS

A summary of the regulatory
environment is included in the combined Form 10-K filed by Alliant Energy, IP&L and
WP&L for the year ended Dec. 31, 2003. Set forth below are recent developments
relating to the regulatory environment.

Details of Alliant Energys rate
cases impacting its historical and future results of operations are as follows (dollars in
millions):

|                 | Expected | Return  |          
|---------------- | -------- | ------- | ---------
|                 | Interim  | Interim | Final    
|                 | Utility  | Filing  | Increase 
|Case             | Type     | Date    | Requested
|                
|WP&L:            |          |         |          
|2003 retail      | E/G/W    | 5/02    | $123     
|2004 retail      | E/G/W    | 3/03    | 87       
|Wholesale        | E        | 2/02    | 6        
|Wholesale        | E        | 3/03    | 5        
|South Beloit    
|retail - IL      | G/W      | 10/03   | 1        
|2004 retail     
|(fuel-only)      | E        | 2/04    | 16       
|IP&L retail - IA | E        | 3/02    | 82       
|IP&L retail - IA | G        | 7/02    | 20       
|IP&L retail - IA | E        | 3/04    | 149      
|IP&L retail - MN | E        | 5/03    | 5        

|(1) |  | Interim rate relief is implemented, subject to refund, pending determination of
               final rates. The final rate relief granted replaces the amount of interim rate
               relief granted.
|--- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(2) |  | Since the final increase was lower than the interim relief granted, a refund to
               customers was made in 2003.
|--- |  | --------------------------------------------------------------------------------------------------------------------------

|(3) |  | IP&L
requested interim rate relief of                approximately $106 million. The Office of
Consumer Advocate, a Division of the                Iowa Department of Justice
responsible for representing the interests of Iowa                utility customers
before the IUB, has recommended that the IUB approve an                increase not in
excess of $95.8 million. Under IUB procedures, IP&L expects                an interim
rate order to be issued in June 2004.
|--- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|(4) |  | In April 2004, a final rate order for a $0.2 million increase was received.
               Since the final increase was lower than the interim relief granted, a refund to
               customers will likely be made in 2004. IP&L has fully reserved for the
               potential refund as of March 31, 2004. Also in April 2004, IP&L filed a
               request for reconsideration. Under Minnesota law, the final order previously
               issued by the MPUC has been suspended in light of the reconsideration request.
               The MPUC is expected to act on the reconsideration within 30 days, at which time
               it will issue a decision either granting or denying IP&Ls request.
|--- |  | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

With the exception of recovering a
return on IP&Ls Emery plant, which is a large component of IP&Ls
retail Iowa electric rate case filed in March 2004, a significant portion of the rate
increases included in the previous table reflect the recovery of increased costs incurred
by IP&L and WP&L, or costs they expect to incur, thus the increase in revenues
related to these rate increases have not resulted or are not expected to result in a
corresponding increase in net income.

In March 2004, a new ratemaking law
was enacted in Iowa. The new law allows utilities to place in effect interim rates,
subject to refund, without review by the IUB within ten days of filing a general rate
increase request. The law also allows the IUB to consider known and measurable changes in
costs and revenues occurring within nine months from the end of the historical test year
in setting final rates in a rate case. Both of these changes are designed to mitigate
regulatory lag in Iowa ratemaking, which uses a historical versus projected test year in
setting rates. IP&L does not expect this new law to have any impact on its pending
retail electric rate case in Iowa as it is only expected to impact future Iowa rate cases.

27

# ALLIANT ENERGY RESULTS
OF OPERATIONS

Unless otherwise noted, all per
share references in the Results of Operations section refer to earnings per
diluted share.

Overview  First Quarter
Results  Alliant Energys net income (loss) and EPS for the first
quarter were as follows (dollars in millions; totals may not foot due to rounding):

|                                                      | 2004       | 2003
|----------------------------------------------------- | ---------- | ----
|                                                      |           
|Continuing operations:                                | Net Income | EPS 
|                                                      |           
|Domestic utility *                                    |            | $33 
|Non-regulated (Resources) *                           |            | 3   
|Alliant Energy parent and other (primarily taxes,     |           
|interest and administrative and general) *            |            | (3  
|Effect of additional shares outstanding *             |            |     
|                                                      |           
|Income from continuing operations                     |            | 34  
|Loss from discontinued operations                     |            | --  
|Cumulative effect of changes in accounting principles |            | --  
|                                                      |           
|Net income (loss)                                     |            | $34 
|                                                      |           

|* |  | The 2004 EPS amounts have been computed based on the average diluted shares outstanding in
2003. For purposes of the table above, Alliant Energy reports the impact of increased
shares outstanding as a separate earnings variance item if it is material.
|- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

The increase in domestic utility
income from continuing operations was primarily due to higher electric margins, which
were partially offset by higher utility operating expenses. The significant improvement
in Alliant Energys non-regulated results from continuing operations was primarily
due to improved results from its International business unit.

Domestic Utility Electric
Margins  Electric margins and MWh sales for Alliant Energy for the three
months ended March 31 were as follows (in thousands):

|                             | Revenues and Costs | MWhs Sold
|---------------------------- | ------------------ | ---------
|                             |                   
|                             | 2004               | 2003     
|                             |                   
|Residential                  |                    | $177,285 
|Commercial                   |                    | 95,505   
|Industrial                   |                    | 133,701  
|                             |                    |          
|Total from retail customers  |                    | 406,491  
|Sales for resale             |                    | 49,474   
|Other                        |                    | 11,941   
|                             |                    |          
|Total revenues/sales         |                    | 467,906  
|                             |                    |          
|Electric production fuel and |                   
|purchased-power expense      |                    | 198,051  
|                             |                    |          
|Margin                       |                    | $269,855 
|                             |                    |          

Electric margins increased $23.1
million, or 9%, primarily due to the impact of various rate increases implemented during
the last 12 months, which included increased revenues to recover a significant portion of
higher utility operating expenses, the impact on the comparison of a significant under
recovery of purchased-power and fuel costs at WP&L in the first quarter of 2003 and
increased retail sales resulting from continued customer and other sales growth. These
items were partially offset by the impact of seasonal rates at WP&L, implemented for
the first time in April 2003, and slightly milder weather in the first quarter of 2004
compared to the same period in 2003. Electric margins for the first quarter of 2004 were
also negatively impacted by higher than anticipated fuel and purchased-power costs at
WP&L. WP&L filed a fuel-only rate case in the first quarter of 2004 and an interim
rate increase of approximately $16 million was implemented in late March 2004.

In April 2003, WP&L implemented
seasonal electric rates that are designed to result in higher rates for the peak demand
period from June 1 through Sept. 30 and lower rates in all other periods during each
calendar year. As a result, total annual revenues are not expected to be impacted
significantly. However, the first quarter of 2004 margins were approximately $7 million
lower than the same period in 2003, all other things being equal, given the seasonal rates
were not yet effective in the first quarter of 2003.

28

Domestic Utility Gas
Margins Gas margins and Dth sales for Alliant Energy for the three months
ended March 31 were as follows (in thousands):

|                     | Revenues and Costs | Dths Sold
|-------------------- | ------------------ | ---------
|                     |                   
|                     | 2004               | 2003     
|                     |                   
|Residential          |                    | $145,399 
|Commercial           |                    | 77,283   
|Industrial           |                    | 11,473   
|Transportation/other |                    | 14,714   
|                     |                    |          
|Total revenues/sales |                    | 248,869  
|                     |                    |          
|Cost of gas sold     |                    | 184,715  
|                     |                    |          
|Margin               |                    | $64,154  
|                     |                    |          

Gas margins decreased $5.4 million,
or 8%, primarily due to lower sales, which were partially due to milder weather conditions
in the first quarter of 2004 compared with the same period in 2003, and the impact of
final Iowa retail gas rates effective in August 2003 being lower than interim rates that
were in effect in the first quarter of 2003. These items were partially offset by improved
results of $2 million from WP&Ls performance-based commodity cost recovery
program (benefits are shared by ratepayers and shareowners).

Refer to Rates and Regulatory
Matters for discussion of various electric and gas rate filings.

Non-regulated Revenues
Details regarding Alliant Energys non-regulated revenues for the three
months ended March 31 were as follows (in thousands):

|                              | 2004 | 2003    
|----------------------------- | ---- | --------
|                              |     
|Integrated Services           |      | $108,638
|International                 |      | 36,301  
|Non-regulated Generation      |      | 3,671   
|Other (includes eliminations) |      | 6,243   
|                              |     
|                              |      | $154,853
|                              |     

The decreased Integrated Services
revenues were primarily due to decreased gas revenues at Alliant Energys natural gas
marketing business, NG Energy Trading, LLC, including reduced sales opportunities as a
result of less volatility in gas prices and lower natural gas prices. The increased
International revenues were primarily due to the acquisition of an additional combined
heat and power facility in China in the second quarter of 2003.

Other Operating Expenses
Other operation and maintenance expense for the domestic utilities increased
$7.2 million, largely due to increases in employee and retiree benefits (comprised of
compensation, medical and pension costs).

Non-regulated operation and
maintenance expenses for the three months ended March 31 were as follows (in thousands):

|                              | 2004 | 2003    
|----------------------------- | ---- | --------
|                              |     
|Integrated Services           |      | $104,917
|International                 |      | 26,618  
|Non-regulated Generation      |      | 1,083   
|Other (includes eliminations) |      | 6,812   
|                              |     
|                              |      | $139,430
|                              |     

The Integrated Services and International
variances were largely driven by the same factors impacting the revenue variances
discussed previously. The International increase was also impacted by higher coal costs
for its generating facilities in China, partially offset by lower compensation expense.

Depreciation and amortization expense
increased $5.4 million, primarily due to utility property additions, partially offset by
lower software amortization at WP&L.

Interest Expense and Other
Interest expense decreased$11.0 million primarily due to lower average
borrowings as a result of debt retirements during the last 12 months, and credit facility
fees incurred at Resources in 2003.

29

Loss on early extinguishment of debt
in the first quarter of 2004 includes debt repayment premiums and charges for the
unamortized debt expenses related to long-term debt retirements of $20 million of senior
notes at Resources.

Equity (income) loss from Alliant
Energys unconsolidated investments for the three months ended March 31 was as
follows (in thousands):

|                                                   | 2004 | 2003    
|-------------------------------------------------- | ---- | --------
|                                                   |     
|Brazil                                             |      | ($12,582
|ATC                                                |      | (4,485  
|New Zealand                                        |      | (3,568  
|Alliant Energy Synfuel LLC (excludes tax benefits) |      | 4,743   
|Other                                              |      | (735    
|                                                   |     
|                                                   |      | ($16,627
|                                                   |     

Equity income from unconsolidated
investments increased $20.9 million. The improved results for Brazil were primarily due to
rate increases implemented at the Brazilian operating companies and a gain of $5.1 million
(represents Alliant Energys allocated portion of the total gain) realized in the
first quarter of 2004 from the sale of two hydroelectric plants. The increased earnings
for New Zealand were primarily due to higher electric margins resulting from higher energy
prices.

Allowance for funds used during
construction (AFUDC) increased $3.2 million primarily due to ongoing construction of the
Emery plant. Interest income and other decreased $4.6 million primarily due to lower
interest income from loans to discontinued operations due to asset sales during 2003.

Income Taxes The
effective income tax rates were 28.1% and 30.3% for the first quarter of 2004 and 2003,
respectively. The lower rate was primarily due to the impact of higher non-taxable income
from foreign operations.

Loss from Discontinued
Operations  Refer to Note 7 of Alliant Energys Notes to
Condensed Consolidated Financial Statements for discussion of Alliant Energys
discontinued operations.

Cumulative Effect of Changes in
Accounting Principles  In the first quarter of 2003, Alliant Energy recorded
after-tax charges of $4 million and $2 million for the cumulative effect of changes in
accounting principles related to the adoption on Jan. 1, 2003 of SFAS 143 and EITF Issue
02-3, Issues Related to Accounting for Contracts Involved in Energy Trading and Risk
Management Activities within WPC and Integrated Services, respectively.

# IP&L RESULTS OF
OPERATIONS

Overview  First Quarter
Results  Earnings available for common stock decreased $9.7 million,
primarily due to increased operating expenses and lower gas margins.

Electric Margins 
Electric margins and MWh sales for IP&L for the three months ended March 31 were as
follows (in thousands):

|                             | Revenues and Costs | MWhs Sold
|---------------------------- | ------------------ | ---------
|                             |                   
|                             | 2004               | 2003     
|                             |                   
|Residential                  |                    | $93,730  
|Commercial                   |                    | 54,592   
|Industrial                   |                    | 77,182   
|                             |                    |          
|Total from retail customers  |                    | 225,504  
|Sales for resale             |                    | 9,852    
|Other                        |                    | 6,926    
|                             |                    |          
|Total revenues/sales         |                    | 242,282  
|                             |                    |          
|Electric production fuel and |                   
|purchased-power expense      |                    | 85,757   
|                             |                    |          
|Margin                       |                    | $156,525 
|                             |                    |          

Electric margins decreased $1.1
million, or 1%, largely due to the impact of slightly milder weather in the first quarter
of 2004 compared to the same period in 2003 and a reserve for the potential 2004 refund to
customers due to the Minnesota final electric rates being lower than the interim relief
effective in July 2003. These items were partially offset by higher wheeling revenues. In
April 2004, IP&L filed for reconsideration of the final electric rates with the MPUC.

30

Gas Margins  Gas
margins and Dth sales for IP&L for the three months ended March 31 were as follows (in
thousands):

|                     | Revenues and Costs | Dths Sold
|-------------------- | ------------------ | ---------
|                     |                   
|                     | 2004               | 2003     
|                     |                   
|Residential          |                    | $83,222  
|Commercial           |                    | 44,193   
|Industrial           |                    | 7,599    
|Transportation/other |                    | 2,691    
|                     |                    |          
|Total revenues/sales |                    | 137,705  
|                     |                    |          
|Cost of gas sold     |                    | 107,292  
|                     |                    |          
|Margin               |                    | $30,413  
|                     |                    |          

Gas margins decreased $4.5 million,
or 13%, primarily due to the impact of final Iowa retail gas rates effective in August
2003 being lower than interim rates that were in effect in the first quarter of 2003 and
lower sales, which were partially due to slightly milder weather in the first quarter of
2004 compared to the same period in 2003.

Refer to Rates and Regulatory
Matters for discussion of IP&Ls electric and gas rate filings.

Steam and Other Revenues
 Steam and other revenues decreased $3.5 million primarily due to lower
construction management revenues from WindConnect due to the current uncertainty
regarding extension of the federal renewable energy production tax credit. The decrease
was largely offset by lower other operation and maintenance expenses related to
IP&Ls WindConnect program.

Other Operating Expenses
 Other operation and maintenance expenses increased $3.6 million primarily due
to increases in employee and retiree benefits (comprised of compensation, medical and
pension costs), partially offset by lower expenses for WindConnect. Depreciation and
amortization expense increased $6.8 million primarily due to property additions.

Interest Expense and Other
 AFUDC increased $3.7 million due to ongoing construction of the Emery plant.

Income Taxes  The
effective income tax rates were 41.3% and 39.2% for the first quarter of 2004 and 2003,
respectively. The increase was primarily due to a decrease in the Alliant Energy tax
benefit allocated to IP&L pursuant to the provisions of PUHCA.

# WP&L RESULTS OF
OPERATIONS

Overview  First Quarter
Results  Earnings available for common stock increased $12.2 million,
primarily due to higher electric margins, partially offset by a higher effective income
tax rate.

Electric Margins 
Electric margins and MWh sales for WP&L for the three months ended March 31 were as
follows (in thousands):

|                             | Revenues and Costs | MWhs Sold
|---------------------------- | ------------------ | ---------
|                             |                   
|                             | 2004               | 2003     
|                             |                   
|Residential                  |                    | $83,555  
|Commercial                   |                    | 40,913   
|Industrial                   |                    | 56,519   
|                             |                    |          
|Total from retail customers  |                    | 180,987  
|Sales for resale             |                    | 39,622   
|Other                        |                    | 5,015    
|                             |                    |          
|Total revenues/sales         |                    | 225,624  
|                             |                    |          
|Electric production fuel and |                   
|purchased-power expense      |                    | 112,294  
|                             |                    |          
|Margin                       |                    | $113,330 
|                             |                    |          

31

Electric margins increased $24.2
million, or 27%, primarily due to the implementation of rate increases during the last 12
months, which included increased revenues to recover a significant portion of
WP&Ls increased operating expenses, the impact on the comparison of a
significant under recovery of purchased-power and fuel costs in the first quarter of 2003
and increased retail sales resulting from continued customer and other sales growth. These
items were partially offset by the impact of implementing seasonal rates in 2003 for the
first time and slightly milder weather in the first quarter of 2004 compared with the same
period in 2003. Electric margins for the first quarter of 2004 were also negatively
impacted by higher than anticipated fuel and purchased-power costs. WP&L filed a
fuel-only rate case in the first quarter of 2004 and an interim rate increase of
approximately $16 million was implemented in late March 2004. Refer to Alliant
Energy Results of Operations for further discussion of seasonal electric rates.

Gas Margins  Gas
margins and Dth sales for WP&L for the three months ended March 31 were as follows (in
thousands):

|                     | Revenues and Costs | Dths Sold
|-------------------- | ------------------ | ---------
|                     |                   
|                     | 2004               | 2003     
|                     |                   
|Residential          |                    | $62,177  
|Commercial           |                    | 33,090   
|Industrial           |                    | 3,874    
|Transportation/other |                    | 12,023   
|                     |                    |          
|Total revenues/sales |                    | 111,164  
|                     |                    |          
|Cost of gas sold     |                    | 77,423   
|                     |                    |          
|Margin               |                    | $33,741  
|                     |                    |          

Gas margins decreased $0.9 million,
or 3%, primarily due to lower sales, which were partially due to milder weather conditions
in the first quarter of 2004 compared with the same period in 2003, partially offset by
improved results of $2 million from WP&Ls performance-based commodity cost
recovery program (benefits are shared by ratepayers and shareowners).

Refer to Rates and Regulatory
Matters for discussion of WP&Ls electric and gas rate filings.

Other Operating Expenses
 Other operation and maintenance expenses increased $3.6 million primarily due
to increases in employee and retiree benefits (comprised of compensation, medical and
pension costs) and transmission and distribution expenses. These items were partially
offset by lower maintenance expenses at generating facilities. Depreciation and
amortization expense decreased $2.2 million, primarily due to lower software amortization,
partially offset by property additions.

Income Taxes  The
effective income tax rates were 38.1% and 27.3% for the first quarter of 2004 and 2003,
respectively. The increase was primarily due to a decrease in the Alliant Energy tax
benefit allocated to WP&L pursuant to the provisions of PUHCA.

# LIQUIDITY AND CAPITAL
RESOURCES

Cash Flows for the Three-Month
Periods Selected information from Alliant Energys, IP&Ls
and WP&Ls respective Condensed Consolidated Statements of Cash Flows for the
three months ended March 31 was as follows (in thousands):

|                            | Alliant Energy | IP&L     | WP&L
|--------------------------- | -------------- | -------- | ----
|                            |               
|Cash flows from (used for): | 2004           | 2003     | 2004
|                            |               
|Operating activities        |                | $123,005 |     
|Financing activities        |                | (29,261  | )   
|Investing activities        |                | (139,593 | )   

Alliant Energys cash flows from
operating activities decreased $44 million, primarily due to changes in working capital,
including changes in the levels of accounts receivable sold and timing of accounts payable
disbursements, partially offset by the timing of collections from customers; cash flows
used for financing activities increased $160 million, primarily due to changes in the
amounts of debt issued and retired; and cash flows used for investing activities decreased
$155 million, primarily due to the 2003 acquisition by Resources of a 309-MW,
non-regulated, tolled, natural gas-fired power plant in Neenah, Wisconsin. IP&Ls
cash flows from operating activities decreased $21 million, primarily due to changes in
working capital; cash flows used for financing activities increased $61 million, primarily
due to changes in the amounts of commercial paper issued and retired; and cash flows used
for investing activities decreased $96 million, primarily due to lower construction and
acquisition expenditures associated with the construction of the Emery plant.
WP&Ls cash flows from operating activities decreased $7 million, primarily due
to changes in working capital.

32

Certain Regulatory
Approvals/Requirements  PUHCA  Alliant Energy is subject
to a PUHCA requirement whereby Alliant Energys common equity balance must be at
least 30% of its total consolidated capitalization, including short-term debt. Alliant
Energys common equity ratio as of March 31, 2004, as computed under this
requirement, was 47.1%.

State Regulatory Agencies
 In March 2004, IP&L received the necessary regulatory authorization to
increase short-term borrowings from $250 million to $300 million. In March 2004, WP&L
discontinued its utility customer accounts receivable sale program, increasing its
short-term borrowing authority granted by the PSCW to $185 million for general corporate
purposes.

Shelf Registrations
 In 2004, Alliant Energy, IP&L and WP&L each filed separate shelf
registrations with the SEC. Alliant Energys shelf registration became effective in
April 2004 and allows Alliant Energy flexibility to offer from time to time up to an
aggregate of $300 million of common stock, stock purchase contracts and stock purchase
units. The new shelf registration terminates the joint shelf registration filed by Alliant
Energy and Resources in 2003. IP&Ls shelf registration became effective in April
2004 and allows IP&L flexibility to offer from time to time up to an aggregate of $210
million of preferred stock, senior unsecured debt securities and collateral trust bonds.
IP&L issued $100 million of senior debentures in May 2004 under this shelf
registration. After giving effect to this offering, $110 million remains available under
the IP&L shelf registration. The new shelf registration terminates the shelf
registration filed by IP&L in 2003. WP&Ls shelf registration became
effective in April 2004 and allows WP&L flexibility to offer from time to time up to
an aggregate of $150 million of its preferred stock, senior unsecured debt securities and
first mortgage bonds.

Cash and Temporary Cash
Investments  As of March 31, 2004, Alliant Energy and its subsidiaries had
approximately $196 million of cash and temporary cash investments, of which approximately
$64 million consisted of deposits in foreign bank accounts. Due to Alliant Energy electing
permanent investment of earnings for federal income tax purposes for certain foreign
subsidiaries, a majority of the cash held in foreign banks cannot be repatriated without
material tax obligations. Alliant Energy plans to use a portion of this cash held in
foreign bank accounts to invest in future capital projects in China.

Sale of Accounts Receivable
 Refer to Note 11 of Alliant Energys Notes to Condensed Consolidated
Financial Statements for information on WP&Ls discontinuance of
participation in the utility customer accounts receivable sale program.

Short-term Debt
Information regarding commercial paper at March 31, 2004 was as follows (dollars in
millions):

|                          | Alliant    | Parent  |            |       
|------------------------- | ---------- | ------- | ---------- | ------
|Commercial paper:         | Energy     | Company | IP&L       | WP&L  
|                          |           
|Amount outstanding        | $122.5     | $--     | $122.5     | $--   
|Weighted average maturity | 12 days    | N/A     | 12 days    | N/A   
|Discount rates            | 1.12-1.13% | N/A     | 1.12-1.13% | N/A   
|Available capacity        | $527.5     | $200.0  | $127.5     | $200.0

Alliant Energys,
IP&Ls and WP&Ls credit facility agreements contain various covenants,
including the following:

|                                                                                                                          | Covenant              | Status at     
|------------------------------------------------------------------------------------------------------------------------- | --------------------- | --------------
|Covenant Description                                                                                                      | Requirement           | March 31, 2004
|                                                                                                                         
|Alliant Energy:                                                                                                           |                       |               
|Consolidated debt-to-capital ratio                                                                                        | Less than 65%         | 48.5%         
|Consolidated net worth                                                                                                    | At least $1.4 billion | $2.4 billion  
|EBITDA interest coverage ratio (*)                                                                                        | At least 2.5x         | 3.8x          
|IP&L debt-to-capital ratio                                                                                                | Less than 58%         | 47.8%         
|WP&L debt-to-capital ratio                                                                                                | Less than 58%         | 29.8%         
|(*) In compliance with the agreement, results of discontinued operations have been included in this covenant calculation.

Long-term Debt
 In May 2004, IP&L issued $100 million of 6.30% senior debentures due
2034 and used the proceeds to repay short-term debt primarily incurred in the construction of the
Emery plant. In February 2004, Resources retired $10.0 million of its 9.75% senior notes
and $9.5 million of its 7% senior notes, incurring approximately $0.03 per share of debt
repayment premiums.

33

Common Equity
 In March 2004, Alliant Energy filed a registration statement with the SEC that became effective in April 2004, relating to the
registration of approximately 3.4 million shares of Alliant Energy common stock and related common share purchase rights, which may
be issued pursuant to the Alliant Energy Corporation Shareowner Direct Plan.

In connection with Alliant Energy's
April 2004 shelf registration discussed previously, it is Alliant Energy's current intent
to issue up to $150 million of new common stock during the remainder of 2004.  Alliant
Energy has entered into a sales agreement with Cantor Fitzgerald & Co., under which
Alliant Energy may sell from time to time up to 7.5 million shares of its common stock.
 Refer to "Shelf Registrations" for additional information.

Alliant Energy's Board of Directors
has approved an amendment to Alliant Energy's Restated Articles of Incorporation to
increase the number of authorized shares of common stock from 200 million to 240 million,
which Alliant Energy shareowners will vote on at the annual meeting on May 21, 2004.

Off-Balance Sheet
Arrangements  A summary of Alliant Energys off-balance sheet
arrangements is included in the combined Form 10-K filed by Alliant Energy, IP&L and
WP&L for the year ended Dec. 31, 2003 and have not changed materially from those
reported in the 2003 Form 10-K. Refer to Note 8 of Alliant Energys Notes to
Condensed Consolidated Financial Statements for the impact of revised FIN 46
guidance on Alliant Energys tolling and purchased-power agreements.

Contractual Obligations
A summary of Alliant Energys, IP&Ls and WP&Ls
contractual obligations is included in the combined Form 10-K filed by Alliant Energy,
IP&L and WP&L for the year ended Dec. 31, 2003 and have not changed materially
from those reported in the 2003 Form 10-K.

Environmental A
summary of Alliant Energys environmental matters is included in the combined Form
10-K filed by Alliant Energy, IP&L and WP&L for the year ended Dec. 31, 2003 and
have not changed materially from those reported in the 2003 Form 10-K. Refer to
Legal Proceedings for discussion of complaints filed against WP&L and
Alliant Energy regarding the Columbia generating station.

# OTHER MATTERS

Market Risk Sensitive
Instruments and Positions  Alliant Energys primary market risk
exposures are associated with interest rates, commodity prices, equity prices and currency
exchange rates. Alliant Energy has risk management policies to monitor and assist in
controlling these market risks and uses derivative instruments to manage some of the
exposures. A summary of Alliant Energys market risks is included in Alliant
Energys, IP&Ls and WP&Ls combined Form 10-K for the year ended
Dec. 31, 2003 and have not changed materially from those reported in the 2003 Form 10-K.

Accounting Pronouncements
 As of March 31, 2004, Alliant Energy adopted revised FIN 46 guidance. Refer to
Note 8 of Alliant Energys Notes to Condensed Consolidated Financial
Statements for additional information.

Critical Accounting
Policies  A summary of Alliant Energys critical accounting policies is
included in Alliant Energys, IP&Ls and WP&Ls combined Form 10-K
for the year ended Dec. 31, 2003 and have not changed materially from those reported in
the 2003 10-K.

Other Future Considerations
 A summary of Alliant Energys, IP&Ls and WP&Ls other
future considerations is included in the combined Form 10-K filed by Alliant Energy,
IP&L and WP&L for the year ended Dec. 31, 2003 and have not changed materially
from those reported in the 2003 Form 10-K, except as described below. In addition to items
discussed earlier in MD&A, the following items could impact Alliant Energys
future financial condition or results of operations:

Mexico At March 31,
2004, Resources held a secured loan receivable of approximately $81 million from an
unrelated Mexican development company. The loan proceeds were used by the development
company to construct substantially all the infrastructure for the initial phase of a
master-planned resort community known as Laguna del Mar located near Puerto Penasco, State
of Sonora, on the Sea of Cortez. Alliant Energy has concerns regarding the Mexican
development companys ability to timely complete all phases of the project, market
and sell the real estate, and otherwise meet all of its obligations under the loan
documents. Discussions are currently underway between Resources and the owners of the
development company to resolve this matter. Resources is evaluating its alternatives,
which include possibly restructuring a role for its partners or replacing them, a transfer
of ownership and control of the project to Resources or the exercise of Resources
remedies through legal action. Effective Jan. 1, 2004, Resources ceased accruing interest
income related to this loan pending resolution of this matter. If the development of the
project and related real estate sales are not ultimately successfully executed, it is
possible that Alliant Energy could incur material asset valuation charges in the future.
Alliant Energy is unable to predict the ultimate outcome of this matter.

34

Brazil  To complete
earlier plans, the Juiz de Fora facility, a joint venture gas-fired generating facility in
which Alliant Energy holds a 50% direct ownership interest, is scheduled for a 20-MW
expansion from a single cycle to a combined cycle facility at an estimated cost of $24
million. However, initiation of the expansion construction is experiencing some delays due
to disputes with Alliant Energys Brazilian partner regarding the financing and
construction of the Juiz de Fora facility and other matters (as mentioned below). Alliant
Energy is currently discussing with its partner resolution of these matters in order to
ensure timely completion of the project. If the Juiz de Fora combined cycle construction
is not completed as anticipated, the future performance obligations of this generation
asset might be significantly adversely affected. In such an event, Alliant Energy is not
required to invest any additional capital in Juiz de Fora; however, it could lead to
material asset valuation or other charges with respect to Alliant Energys investment
in the Juiz de Fora facility.

Alliant Energy continues to closely
monitor the financial performance of its Brazilian investments. While such performance
improved significantly in 2003, and while Alliant Energy expects continued improvements in
2004, Alliant Energy believes the rate of improvement can be enhanced  particularly
in regard to controlling costs and reduction of debt  and this has been a source of
dispute with its Brazilian partners. In particular, Alliant Energys Brazilian
partners want to use company funds to pay dividends in order to ensure their control over
the operations. Alliant Energy is not interested in and has not sought control of the
operations. However, it has urged that, to the extent funds are available, they would be
better used to pay down debt.

Alliant Energy has been and continues to explore with various parties, including its existing Brazilian partners, all of the options
available to it concerning its investments in Brazil.  Alliant Energy will consider the full range of options potentially available.
Consequently, Alliant Energy is unable to provide any assurances that one or more of the options under review will occur, or that
implementation of any one or more of the options will not result in Alliant Energy incurring a material charge as relates to its
investments in Brazil as the company cannot currently predict the ultimate outcome of these reviews and discussions.

China  The generating
plants included in Alliant Energys China portfolio are currently experiencing
higher than anticipated coal and related costs due primarily to government
allocations and infrastructure bottlenecks.  Alliant Energy is attempting to mitigate
the impact of these cost increases by working with local Chinese authorities to increase
the supply of lower cost coal, working with local Chinese power commissions to enable it
to recover the higher costs through tariffs and reviewing for other ways to offset these
cost increases within its operations.  Alliant Energy is unable to predict the
future of these costs in China or the ultimate outcome of its efforts to
mitigate the impact of any cost increases.

# ITEM 3. QUANTITATIVE AND
QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Quantitative and Qualitative
Disclosures About Market Risk are reported under Item 2 MD&A Other Matters
 Market Risk Sensitive Instruments and Positions.

# ITEM 4. CONTROLS AND
PROCEDURES

Alliant Energys,
IP&Ls and WP&Ls management evaluated, with the participation of each
of Alliant Energys, IP&Ls and WP&Ls Chief Executive Officer
(CEO), Chief Financial Officer (CFO) and Disclosure Committee, the effectiveness of the
design and operation of Alliant Energys, IP&Ls and WP&Ls
disclosure controls and procedures as of the end of the quarter ended March 31, 2004
pursuant to the requirements of the Securities Exchange Act of 1934, as amended. Based on
their evaluation, the CEO and the CFO concluded that Alliant Energys,
IP&Ls and WP&Ls disclosure controls and procedures were effective as
of the end of the quarter ended March 31, 2004.

There was no change in Alliant
Energys, IP&Ls and WP&Ls internal control over financial
reporting that occurred during the quarter ended March 31, 2004 that has materially
affected, or is reasonably likely to materially affect, Alliant Energys,
IP&Ls or WP&Ls internal control over financial reporting.

# PART II  OTHER
INFORMATION

# ITEM 1. LEGAL PROCEEDINGS

Alliant Energy and
WP&LIn the fourth quarter of 2003, the
Wisconsin Environmental Law Advocates (WELA) filed a complaint in the U.S. District Court
for the Western District of Wisconsin against WP&L and Alliant Energy alleging
violations of the federal Clean Water Act at the Columbia generating station. The
complaint seeks certain upgrades to Columbias wastewater treatment program, as well
as unspecified penalties and attorney fees. In addition, the Wisconsin Department of
Natural Resources has been pursuing enforcement of this same matter and recently referred
the matter to the Wisconsin Department of Justice (WDOJ). In March 2004, WDOJ filed a
complaint in state court against WP&L and Alliant Energy alleging similar violations.
Alliant Energy, WDOJ and WELA have initiated settlement discussions. Alliant Energy
believes that the total cost to resolve any potential penalties and implement any required
upgrades in this matter will not be material.

35

# ITEM 6. EXHIBITS AND
REPORTS ON FORM 8-K

(a)    
          Exhibits: The following Exhibits are filed herewith or incorporated by
          reference.

|4.1 |  | Officer's
Certificate, dated May 3, 2004, creating the 6.30% Senior Debentures due 2034
(incorporated by reference to                  Exhibit 4.1 to IP&L's Form 8-K, dated May
3, 2004)
|--- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|10.1 |  | Sales
Agreement, dated April 9, 2004, between Alliant Energy and Cantor Fitzgerald & Co.
(incorporated by reference                  to Exhibit 1.3 to Alliant Energy's
Registration Statement on Form S-3 (Registration No. 333-114361))
|---- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|10.2 |  | Key
Executive Employment and Severance Agreement, dated Feb. 4, 2004, by and between Alliant
Energy and T.L. Aller
|---- |  | ------------------------------------------------------------------------------------------------------------------

|10.3 |  | Employment
Agreement by and between Alliant Energy and Erroll B. Davis, Jr., amended and restated as
of March 26, 2004
|---- |  | ----------------------------------------------------------------------------------------------------------------------

|10.4 |  | Supplemental
Retirement Agreement by and between Alliant Energy and T.L. Aller (incorporated by
reference to Exhibit                  10.7 to Alliant Energy's Form 10-Q for the quarter
ended Sept. 30, 2003)
|---- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|31.1 |  | Certification
of the Chairman and CEO for Alliant Energy
|---- |  | --------------------------------------------------------

|31.2 |  | Certification
of the Senior Executive Vice President and CFO for Alliant Energy
|---- |  | -------------------------------------------------------------------------------

|31.3 |  | Certification
of the Chairman and CEO for IP&L
|---- |  | ----------------------------------------------

|31.4 |  | Certification
of the CFO for IP&L
|---- |  | ---------------------------------

|31.5 |  | Certification
of the Chairman and CEO for WP&L
|---- |  | ----------------------------------------------

|31.6 |  | Certification
of the CFO for WP&L
|---- |  | ---------------------------------

|32.1 |  | Written
Statement of the CEO and CFO Pursuant to 18 U.S.C.§1350 for Alliant Energy
|---- |  | ----------------------------------------------------------------------------------

|32.2 |  | Written
Statement of the CEO and CFO Pursuant to 18 U.S.C.§1350 for IP&L
|---- |  | ------------------------------------------------------------------------

|32.3 |  | Written
Statement of the CEO and CFO Pursuant to 18 U.S.C.§1350 for WP&L
|---- |  | ------------------------------------------------------------------------

(b) Reports on Form 8-K:

Alliant EnergyAlliant Energy filed a Current
Report on Form 8-K, dated Jan. 30, 2004, reporting (under Items 7 and 12) that it issued
a press release announcing its earnings for the fourth quarter and year ended Dec. 31,
2003, its earnings guidance for 2004 and projected 2004 and 2005 capital expenditures.

IP&L  None.

WP&L None.

36

# SIGNATURES

Pursuant to the requirements of the
Securities Exchange Act of 1934, Alliant Energy Corporation, Interstate Power and Light
Company and Wisconsin Power and Light Company have each duly caused this report to be
signed on its behalf by the undersigned thereunto duly authorized on the 6th day of May
2004.

|ALLIANT ENERGY CORPORATION         |                                                        
|---------------------------------- | -------------------------------------------------------
|Registrant                        
|                                  
|By: /s/ John E. Kratchmer          | Vice President-Controller and Chief Accounting Officer 
|John E. Kratchmer                  | (Principal Accounting Officer and Authorized Signatory)
|                                  
|                                  
|INTERSTATE POWER AND LIGHT COMPANY
|Registrant                        
|                                  
|By: /s/ John E. Kratchmer          | Vice President-Controller and Chief Accounting Officer 
|John E. Kratchmer                  | (Principal Accounting Officer and Authorized Signatory)
|                                  
|                                  
|WISCONSIN POWER AND LIGHT COMPANY 
|Registrant                        
|                                  
|By: /s/ John E. Kratchmer          | Vice President-Controller and Chief Accounting Officer 
|John E. Kratchmer                  | (Principal Accounting Officer and Authorized Signatory)

37