UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

 

FORM 10-K

 

| x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934 |
|---|---------------------------------------------------------------------------------------|

|   | For the fiscal year ended **December 31, 2008** |
|--------|-------------------------------------------------|

or

 

| o | 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-K is separately filed by Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company.  Information contained in the Form 10-K 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.

 

Securities registered pursuant to Section 12 (b) of the Act:

|                               |                                        | Name of Each Exchange   |
|------------------------------------|---------------------------------------------|-------------------------|
|                               | Title of Class                              | on Which Registered     |
| Alliant Energy Corporation         | Common Stock, $0.01 Par Value               | New York Stock Exchange |
| Alliant Energy Corporation         | Common Share Purchase Rights                | New York Stock Exchange |
| Interstate Power and Light Company | 8.375% Series B Cumulative Preferred Stock, | New York Stock Exchange |
|                               | $0.01 Par Value                             |                    |
| Interstate Power and Light Company | 7.10% Series C Cumulative Preferred Stock,  | New York Stock Exchange |
|                               | $0.01 Par Value                             |                    |
| Wisconsin Power and Light Company  | 4.50% Preferred Stock, No Par Value         | NYSE Alternext US LLC   |

 

Securities registered pursuant to Section 12 (g) of the Act:  Wisconsin Power and Light Company Preferred Stock

|   | (Accumulation without Par Value) |
|--------|----------------------------------|

 

Indicate by check mark if the registrants are well-known seasoned issuers, as defined in Rule 405 of the Securities Act.

 

| Alliant Energy Corporation         | Yes x | No o |
|------------------------------------|-------|------|
| Interstate Power and Light Company | Yes o | No x |
| Wisconsin Power and Light Company  | Yes o | No x |

 

Indicate by check mark if the registrants are not required to file reports pursuant to Section 13 or Section 15(d) of the Act.

Yes o  No x

 

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 o

 

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