UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, 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, 2009** |
|--------|---------------------------------------------------|

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-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 o

 

Indicate by check mark whether the registrants have submitted electronically and posted on their corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrants were required to submit and post such files).  Yes o  No o

 

Indicate by check mark whether the registrants are large accelerated filers, accelerated filers, non-accelerated filers, or smaller reporting companies.  See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

|                               |        |        |            | Smaller   |
|------------------------------------|-------------|-------------|-----------------|-----------|
|                               | Large       |        |            | Reporting |
|                               | Accelerated | Accelerated | Non-accelerated | Company   |
|                               | Filer       | Filer       | Filer           | Filer     |
| Alliant Energy Corporation         | x           |        |            |      |
| Interstate Power and Light Company |        |        | x               |      |
| Wisconsin Power and Light Company  |        |        | x               |      |

 

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