Form 11-K 12/31/07

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

 

FORM 11-K

 

x

ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES

 

EXCHANGE ACT OF 1934

 

 

For the fiscal year ended December 31, 2007

 

or

 

o

TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES

 

EXCHANGE ACT OF 1934

 

 

 For the transition period from _____________ to _____________

 

 

 

Commission File Number: 1-9894

 

 

A.

Full title of the plan and address of the plan, if different from that of the issuer named below:

 

 

 ALLIANT ENERGY CORPORATION 401(k) SAVINGS PLAN

 

 

B.

Name of issuer of the securities held pursuant to the plan and the address of its principal

executive office:

 

ALLIANT ENERGY CORPORATION

4902 North Biltmore Lane

Madison, Wisconsin 53718

 

 

 

 

 

 

 

REQUIRED INFORMATION

 

The following financial statements and schedules of the Alliant Energy Corporation 401(k) Savings Plan, prepared in accordance with the financial reporting requirements of the Employee Retirement Income Security Act of 1974, as amended, are filed herewith.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 1 of 18 pages

Exhibit Index is on page 17

 

1

ALLIANT ENERGY CORPORATION

 

401(k) SAVINGS PLAN

 

FINANCIAL STATEMENTS AS OF DECEMBER 31, 2007 AND 2006

 

AND FOR THE YEAR ENDED DECEMBER 31, 2007,

 

SUPPLEMENTAL SCHEDULES AS OF AND FOR THE YEAR ENDED DECEMBER 31, 2007, AND

 

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

 

2

ALLIANT ENERGY CORPORATION

 

401(k) SAVINGS PLAN

 

TABLE OF CONTENTS

 

 

Page No.

 

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

4

 

FINANCIAL STATEMENTS

 

 

Statements of Net Assets Available for Benefits

 

 as of December 31, 2007 and 2006

5

 

 

Statement of Changes in Net Assets Available for Benefits

 

 for the Year Ended December 31, 2007

6

 

NOTES TO FINANCIAL STATEMENTS

7-12

 

SUPPLEMENTAL SCHEDULES

 

 

Form 5500, Schedule H, Part IV, line 4i - Schedule of Assets (Held at End of Year)

 

as of December 31, 2007

13

 

 

Form 5500, Schedule H, Part IV, line 4i - Schedule of Assets (Acquired and Disposed

 

of Within Year) for the Year Ended December 31, 2007

14

 

 

Form 5500, Schedule H, Part IV, line 4j - Schedule of Reportable Transactions

 

for the Year Ended December 31, 2007

15

 

SIGNATURES

16

 

EXHIBIT INDEX

17

 

 

Consent of Independent Registered Public Accounting Firm

18

 

 

3

Report of Independent Registered Public Accounting Firm

 

To the Total Compensation Committee and Participants of the Alliant Energy Corporation 401(k) Savings Plan:

 

We have audited the accompanying statements of net assets available for benefits of Alliant Energy Corporation 401(k) Savings Plan (the “Plan”) as of December 31, 2007 and 2006, and the related statement of changes in net assets available for benefits for the year ended December 31, 2007. These financial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion on these financial statements based on our audits.

 

We conducted our audits in accordance with standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Plan’s internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

 

In our opinion, such financial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of December 31, 2007 and 2006, and the changes in net assets available for benefits for the year ended December 31, 2007, in conformity with accounting principles generally accepted in the United States of America.

 

Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole. The supplemental schedules of (1) assets (held at end of year) as of December 31, 2007, (2) assets (acquired and disposed of within year) for the year ended December 31, 2007, and (3) reportable transactions for the year ended December 31, 2007, are presented for the purpose of additional analysis and are not a required part of the basic financial statements, but are supplementary information required by the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. These schedules are the responsibility of the Plan’s management. Such schedules have been subjected to the auditing procedures applied in our audit of the basic 2007 financial statements and, in our opinion, are fairly stated in all material respects when considered in relation to the basic financial statements taken as a whole.

 

/s/ Deloitte & Touche LLP

 

Milwaukee, Wisconsin

June 27, 2008

 

4

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS

  December 31,
  2007 2006
 
    Investment income receivable   $--   $220,277  
 
    Investments, other than participant promissory notes (Refer to Notes 7 and 8)  632,459,824   577,699,020  
    Participant promissory notes  9,904,024   9,305,638  
 
        Total investments  642,363,848   587,004,658  
 
Net assets available for benefits at fair value   642,363,848   587,224,935  
    Adjustments from fair value to contract value for fully benefit- 
      responsive investment contracts (Refer to Note 2)  539,804   435,698  
 
Net assets available for benefits   $642,903,652   $587,660,633  
 

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

5

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS

For the Year Ended December 31, 2007

   
Net assets available for benefits - beginning of year      $587,660,633  
   
Contributions:  
     Cash contributions from employees    29,025,000  
     Employer contributions:  
         Cash for purchase of Alliant Energy Corporation common stock    8,234,907  
         Cash    986,789  
     Rollovers from other qualified plans    919,064  
   
Investment income:  
     Net appreciation in fair value of investments (Refer to Note 7)    24,575,585  
     Interest and dividends    31,081,984  
   
Distributions to participants       (39,580,310 )
 
   Net increase     55,243,019  
 
 Net assets available for benefits - end of year      $642,903,652  
 

The accompanying Notes to Financial Statements are an integral part of this statement.

6

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

 

NOTES TO FINANCIAL STATEMENTS

FOR THE YEAR ENDED DECEMBER 31, 2007

 

Note 1.

Description of the Plan

 

The Alliant Energy Corporation 401(k) Savings Plan (the Plan) is a qualified defined contribution plan under Section 401(k) of the Internal Revenue Code (the Code), as amended, and meets the applicable requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA). The following brief description of the Plan is provided for general information purposes only. More complete information regarding the Plan is provided in the plan document and summary plan description, which have been made available to all eligible Plan participants (participants). The Plan is administered by the Total Compensation Committee (the Committee) and the Plan sponsor is Alliant Energy Corporate Services, Inc. (a direct subsidiary of Alliant Energy Corporation). The Committee reserves the right to terminate, amend or modify the Plan if future conditions warrant such action.

 

Any regular employee of Alliant Energy Corporation and its participating subsidiaries (the Company) age 18 and over may participate in the Plan. Regular full-time employees and regular part-time employees customarily scheduled to work at least half-time may participate immediately following 30 days of service. Part-time employees customarily scheduled to work less than half-time may participate after 12 months of service during which he or she has earned at least 1,000 paid hours.

 

An Employee Stock Ownership Plan (ESOP) is in place within the Plan. Under these provisions, participants have the option to elect to receive cash for any dividends paid on Company common stock within the Plan or to have the dividends reinvested in additional shares based on the current market price. Also, the Company is eligible for the dividend deduction provisions of Section 404(k) of the Code for Company common stock held in the ESOP.

 

Effective Jan. 1, 2006, the Company made changes to the Plan for newly hired non-bargaining employees and certain employees of Alliant Energy Resources, Inc. (Resources) and Cedar Rapids and Iowa City Railway Company (CRANDIC) employees. These changes are also effective for certain newly hired bargaining employees as of the dates per their respective bargaining agreements. For all other non-bargaining employees, the following changes will go into effect on Aug. 1, 2008. The changes include the Company providing matching contributions of $0.50 for each $1 contributed by the participant up to the first 8% of each respective participant’s eligible compensation. In addition, the Company provides a contribution into each active employee’s 401(k) account each pay period based on a percentage of base pay (non-elective Company cash contribution) as follows:

 

 

 

Company

     Age plus Years of Service

 

Contribution

< 49

 

4%

50 – 69

 

5%

70+

 

6%

 

For all other non-bargaining and bargaining employees, the Company provides matching contributions of $0.50 for each $1 contributed by the participant up to the first 6% of each respective participant’s eligible compensation.

 

Beginning Dec. 27, 2007, certain bargaining employees who were eligible to participate in the Plan on or before June 1, 2007, are also eligible for a Company contribution of 1% of their respective eligible compensation. This Company contribution is in addition to any other Company provided match and will be invested in the Alliant Energy Corporation Common Stock Fund. This Company contribution is subject to the three years of service diversification provisions as described below.

 

7

 

                Employee contribution limits for 2007 were as follows:

 

Eligible employee annual contribution limit as a percentage of compensation

50%

Maximum annual contribution limit*

$15,500

*Participants who were at least age 50 by Dec. 31, 2007 were eligible to make additional catch-up contributions of up to $5,000 in 2007. These additional catch-up contributions were not eligible for any Company match.

 

Company contributions are invested in the Alliant Energy Corporation Common Stock Fund, except for the non-elective Company cash contribution. The non-elective Company cash contribution is invested at each participant’s discretion. Effective Oct. 2, 2006, the Plan enhanced its existing diversification provisions by allowing participants with at least three years of service to transfer their Company matching contributions invested in the Alliant Energy Corporation Company Stock Fund to any other investment fund. Previously, Company matching contributions invested in the Alliant Energy Corporation Company Stock Fund could not be transferred to any other investment fund, except for certain participants during the 30-day period immediately prior to retirement and participants age 55 with 10 years of service were eligible to diversify up to 100% of their ESOP account to one or more of the investment options.

 

An “additional” Company contribution is contributed to the accounts of active participants, as of the last day of the Plan year, who contributed at least 6% of compensation during the Plan year and did not receive a Company matching contribution equal to 3% of compensation or for those eligible for a matching contribution equal to 4% of compensation who contributed 8% of compensation during the Plan year. The amount of the “additional” Company contribution is the difference between 3% of compensation or 4% of compensation for certain employees during the Plan year and the amount of Company matching contributions previously received during the Plan year.

 

Participants are immediately vested in their respective employee and employer contributions. Participants may subsequently redesignate the distribution of future contributions or transfer existing balances between investment funds on a daily basis, subject to the limits set forth in the Plan.

 

Contributions under the Plan are held and invested, until distribution, in a Trust Fund maintained by J.P. Morgan Retirement Plan Services LLC (the Trustee or JPMorgan). JPMorgan became the Trustee and recordkeeper effective Oct. 15, 2007. Prior to Oct. 15, 2007, Wachovia Bank, National Association, as successor to Ameriprise Trust Company, served as trustee. On June 1, 2006, Wachovia Bank, National Association acquired Ameriprise Trust Company’s recordkeeping business. Individual accounts are maintained by the Trustee for each participant. Each participant’s account is credited with the participant’s contributions, Company contributions, and an allocation of Plan earnings, and charged with withdrawals and an allocation of Plan losses and administrative expenses. Allocations are based on participant earnings or account balances, as defined. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s vested account balance.

 

The Plan has provisions under which participants who are active employees may take loans up to the lesser of $50,000 or 50% of their total account balance (a $1,000 minimum loan amount and a maximum of three loans for each participant also apply). The Committee determines the loan interest rate pursuant to the Plan. Interest rates on participant loans outstanding ranged from 5.0% to 10.5% at both Dec. 31, 2007 and 2006. Principal and interest are repaid bi-weekly through employee payroll deductions.

 

Note 2.

Summary of Significant Accounting Policies

 

(a) Basis of Accounting - The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP).

 

(b) New Accounting Pronouncements - In September 2006, the Financial Accounting Standard Board issued Statement of Financial Accounting Standards 157, “Fair Value Measurements,” (SFAS 157) which defines fair value, establishes a framework for measuring fair value in GAAP and expands disclosures about fair value measurements. The Plan is required to adopt SFAS 157 on Jan. 1, 2008 and is evaluating the implications of SFAS 157 on its financial statements.

 

8

(c) Accounting for Fully Benefit-Responsive Contracts - In 2006, the Plan adopted Financial Accounting Standards Board Staff Position, FSP AAG INV-1 and SOP 94-4-1, “Reporting of Fully Benefit-Responsive Contracts Held by Certain Investment Companies Subject to the AICPA Investment Company Guide and Defined-Contribution Health and Welfare and Pension Plans” (FSP). As required by the FSP, the statements of net assets available for benefits present investments at fair value as well as an additional line item showing an adjustment of fully benefit-responsive contracts from fair value to contract value. The statement of changes in net assets available for benefits is presented on a contract value basis and was not affected by the adoption of the FSP.

 

(d) Valuation of Investments and Income Recognition - The Plan’s investments are stated at fair value. All Guaranteed Investment Contracts (GICs) held by the Plan are fully benefit-responsive and at Dec. 31, 2007 all were synthetic GICs. The contract value of all GIC investments was $68,374,996 and $48,954,702 at Dec. 31, 2007 and 2006, respectively. The approximate fair value of these investments was $67,835,192 and $48,570,228 at Dec. 31, 2007 and 2006, respectively, based on the fair value of the underlying assets. The weighted average yields for the GICs based on annualized earnings on Dec. 31, 2007 and 2006, were 6.66% and 5.47%, respectively. The weighted average yields for the GICs based on the interest rate credited to participants on Dec. 31, 2007 and 2006, were 5.53% and 5.11%, respectively. Participant loans are carried at unpaid principal balances due, which approximates fair value. All other Plan investments are carried at fair value as determined by quoted market prices or the net asset value of shares held by the Plan on the valuation date. Interest income is accrued when earned. Dividend income is recorded on the ex-dividend date. Investment transactions are recorded on the trade date.

 

(e) Net Appreciation in Fair Value of Investments - Net realized and unrealized appreciation is recorded in the accompanying statement of changes in net assets available for benefits as “Net appreciation in fair value of investments.”

 

(f) Payment of Benefits - Benefit payments to participants are recorded when paid.

 

(g) Expenses - All expenses paid through the Plan are recorded with investment earnings in the accompanying statement of changes in net assets available for benefits. On individual participant statements, prior to the conversion to JPMorgan, investment management and recordkeeping fees were paid from investment earnings prior to crediting earnings to the individual participant account balances. On JPMorgan individual participant statements, recordkeeping fees are reported separate from investment earnings and are paid for directly by the Plan participants. Investment management fees are paid from investment earnings prior to crediting earnings to the individual participant account balances, but can be identified in the investment fund information supplied to participants from JPMorgan. Certain other Plan administrative expenses are absorbed by the Company. Expenses incurred in maintaining Self-Managed Brokerage Accounts are the responsibility of the respective Plan participants.

 

(h) Use of Estimates - The preparation of financial statements in conformity with GAAP requires the Plan administrator to make estimates and assumptions that affect the reported amounts of net assets available for benefits at the date of the financial statements and the reported amounts of changes in net assets available for benefits during the reporting period. Actual results could differ from those estimates.

 

(i) Risk and Uncertainties - The Plan invests in various investments, including common investment funds, mutual funds, common stock of the Company and investment contracts. The Plan also offers a Self-Managed Brokerage Account option which allows participants to invest in a wide range of mutual funds. Investments, in general, are exposed to various risks, such as interest rate, credit, and overall market volatility. Due to the level of risk associated with certain investments, it is reasonably possible that changes in the values of certain investments may occur in the near term and that such changes could materially affect the amounts reported in the financial statements.

 

Note 3.

Tax Status

 

The Internal Revenue Service has determined and informed the Company by a letter dated Aug. 25, 2003, that the Plan and related trust are designed in accordance with the applicable sections of the Code. The Plan has been amended since receiving the determination letter. However, the Committee and the Plan’s tax counsel believe that the Plan is designed and is currently being operated in compliance with the applicable requirements of the Code.

 

9

Note 4.

Plan Termination Provisions

 

Upon termination of the Plan in its entirety, each participant is entitled to receive, in accordance with the terms of the Plan, the entire balance in their account. The Company has no intention to terminate the Plan.

 

Note 5.

Withdrawals and Distributions

 

Withdrawals from participants’ account balances are allowed when participants who are actively employed reach age 70-1/2 (or age 59-1/2 for certain participants). Withdrawals are also allowed due to special “hardship” circumstances. Distributions from the Plan will be made upon termination of employment (by retirement, death, disability or otherwise) if the participant’s account balance is less than $5,000. If a withdrawing participant’s account balance exceeds $1,000 but is less than $5,000, and the participant does not make an election to either have the account paid as a direct rollover or as a cash payment, the distribution will be paid as a direct rollover to an individual retirement account established at the Trustee. If a withdrawing participant’s account balance exceeds $5,000, the participant may elect to defer payment until he or she is age 70-1/2. Distributions can be either in the form of a lump sum or substantially equal annual installments. The unpaid portion of all loans made to the participant, including accrued interest, will be deducted from the amount of the participant account to be distributed. Distributions payable to participants at Dec. 31, 2007 and 2006 were $0 and $227,307, respectively. Distributions payable are not included as a liability within net assets available for benefits in the accompanying financial statements, however, they are recorded as liabilities in the Plan’s Form 5500 (refer to Note 10).

 

Note 6.

Derivative Financial Instruments

 

The Plan did not invest in any material derivative financial instruments during 2007 and 2006.

 

Note 7.

Other Investment Information

 

Investments held which were greater than 5% of the Plan’s net assets available for benefits as of Dec. 31 were as follows:

 

2007

 

2006

Alliant Energy Corporation Common Stock*

$137,986,764

 

$137,820,283

(non-participant directed: $1,171,361 (28,787 shares) and

 

 

 

$817,826 (21,654 shares), respectively)

 

 

 

(participant directed: $136,815,403 (3,362,384 shares) and $137,002,457

 

 

 

(3,627,526 shares), respectively)

 

 

 

American Funds Growth Fund of America, 2,868,962 Class R5 and

 

 

 

2,716,565 Class A shares, respectively

97,544,722

 

89,293,482

State Street Global Advisors S&P 500 Fund, 2,884,397

 

 

 

Class C and 0 shares, respectively

75,891,380

 

--

JPMorgan Intermediate Bond Fund*, 5,225,680 and 0 shares, respectively

61,558,512

 

--

Dodge & Cox Stock Fund, 435,882 and 367,953 shares, respectively

60,265,040

 

56,466,030

American Funds EuroPacific Growth Fund, 1,114,089 Class R5 and

 

 

 

913,251 Class R4 shares, respectively

56,673,723

 

41,991,279

PIMCO Total Return Fund, 3,705,129 and 3,024,733 shares, respectively

39,607,826

 

31,396,730

RiverSource Trust Equity Index Fund III*, 0 and 1,959,874

 

 

 

 

shares, respectively

--

 

78,104,900

* Represents party known to be a party-in-interest to the Plan.

10

 

During 2007, the Plan’s investments, including gains and losses on investments acquired and disposed of, as well as held during the year, appreciated (depreciated) in value as follows:

 

American Funds Growth Fund of America, class C

$14,548,891

Alliant Energy Corporation Common Stock*

11,012,837

American Funds EuroPacific Growth Fund, class R4

8,910,293

RiverSource Trust Equity Index Fund III*

8,677,685

Dreyfus Premier Emerging Markets Fund

6,432,954

State Street Global Advisors S&P Midcap Index Fund

1,952,111

PIMCO Total Return Fund

1,822,106

RiverSource Trust Income Fund I*

518,622

RiverSource Trust Bond Index Fund II*

326,589

State Street Global Advisors Bond Index Fund

203,462

Brown Capital Management Small Company Fund

190,837

Boston Company Emerging Markets Value Equity Fund

37,120

Self-Managed Brokerage Accounts

(7,713)

Wellington Mid Cap Growth Fund

(389,764)

Evergreen Small Cap Value Fund

(488,721)

Janus Advisor Mid Cap Value Fund

(604,720)

Riversource Small Cap Value Fund*

(2,363,184)

Buffalo Small Cap Fund

(2,974,688)

State Street Global Advisors S&P 500 Index Fund

(3,388,376)

American Funds EuroPacific Growth Fund, class R5

(4,181,478)

Dodge & Cox Stock Fund

(5,811,795)

American Funds Growth Fund of America, class R5

(9,847,483)

Net appreciation in fair value of investments

$24,575,585

 

* Represents party known to be a party-in-interest to the Plan.

 

Note 8.

Non-Participant Directed Investments

 

Information about the net assets and the significant components of the changes in net assets relating to the non-participant directed investments was as follows:

 

Dec. 31,

Net assets:

2007

 

2006

Alliant Energy Corporation Common Stock*

$1,171,361

 

$817,826

RiverSource Trust Money Market Fund I*

--

 

12,120

Investment income receivable

--

 

1,659

 

$1,171,361

 

$831,605

 

 

 

Changes in net assets:

2007

 

Employer contributions

$524,406

 

 

 

 

Investment activity:

 

 

Net appreciation in fair value of investments

93,709

 

Investment income

38,655

 

 

 

 

Transfers to participant directed investments (Note 1)

(317,014)

 

 

$339,756

 

* Represents party known to be a party-in-interest to the Plan.

 

11

Note 9.             Related Party Transactions

 

Certain Plan investments are shares of mutual funds and common trust funds managed by an affiliate of the Trustee and shares of common stock of the Company. As of Dec. 31, 2007 and 2006, the Plan held 3,391,171 and 3,649,180 shares of Alliant Energy Corporation common stock with a cost basis of $95,423,377 and $90,603,322 respectively. In 2007 and 2006, the Plan recorded dividend income of $4,444,427 and $4,317,068 respectively, from investments in common stock of the Company. These transactions qualify as exempt party-in-interest transactions.

 

Note 10. Reconciliation to Form 5500

 

Distributions payable to participants are not included as a liability within net assets available for benefits in the accompanying financial statements, however, they are recorded as liabilities in the Plan’s Form 5500. For 2007, net assets available for benefits in the accompanying financial statements are at contract value, however, they are recorded at fair value in the Plan’s Form 5500. The following table reconciles net assets available for benefits per the financial statements to the Plan’s Form 5500 as filed by the Company:

 

 

2007

 

2006

Net assets available for benefits per financial statements

$642,903,652

 

$587,660,633

 

Adjustments:

 

 

 

Fair value to contract value for fully

 

 

 

benefit-responsive investment contracts

(539,804)

 

(435,698)

 

Benefits requested not yet paid

--

 

       (227,307)

 

Amounts reported per Form 5500

$642,363,848

 

$586,997,628

 

 

The following table reconciles the net increase in net assets available for benefits per the financial statements to the Form 5500 as filed by the Company for 2007:

 

 

Net increase

Amounts reported per financial statements

$55,243,019

Adjustments:

 

Changes in adjustment from fair value to contract value

 

for fully benefit-responsive investment contracts

(104,106)

Changes in benefits requested not yet paid

227,307

Amounts reported per Form 5500

$55,366,220

 

 

Note 11. Subsequent Events

 

In May 2008, the Committee and the Board of Directors of Alliant Energy Corporation approved two amendments to the Plan. The first amendment requires the non-elective Company cash contribution to be subject to a three year cliff vesting schedule for new employees hired on July 1, 2008 or later, or on a date agreed to pursuant to the terms of the participant’s respective bargaining agreement. The second amendment allows the Company matching contributions to be invested according to each participant’s investment elections. These amendments will be implemented in 2008.

 

12

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

FORM 5500, SCHEDULE H, PART IV, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)

AS OF DECEMBER 31, 2007

Identity of issue, borrower, Description of investment including maturity date,   Current
lessor, or similar party rate of interest, collateral, par or maturity value Cost* Value

Registered Investment Companies   American Funds Growth Fund of America, 2,868,962 class R5 shares       $97,544,722  
   Dodge & Cox Stock Fund, 435,882 shares       60,265,040  
   American Funds EuroPacific Growth Fund, 1,114,089 class R5 shares       56,673,723  
    PIMCO Total Return Fund, 3,705,129 class I shares       39,607,826  
    Buffalo Small Cap Fund, 1,186,317 shares       28,673,275  
    Riversource Small Cap Value Fund**, 2,194,265 class R5 shares       10,532,472  
    Janus Advisor Mid Cap Value Fund, 408,077 class I shares       7,455,569  
   
Common/Collective Trusts   State Street Global Advisors S&P 500 Fund, 2,884,397 class C shares       75,891,380  
    JPMorgan Intermediate Bond Fund**, 5,225,680 shares       61,558,512  
    Boston Company Emerging Markets Value Equity Fund, 494,988 shares       28,828,279  
    State Street Global Advisors Bond Index Fund, 926,438 class L shares       11,050,561  
    Wellington Mid Cap Growth Fund, 641,895 shares       7,869,637  
    JPMorgan Liquidity Fund**, 3,805,454 shares       3,805,454  
   
Corporate Stocks: Common   Alliant Energy Corporation common stock**, 3,391,171 shares   $95,423,377   137,986,764  
   
Corporate Bonds   CWALT 2007-OA9 A2, Variable rate, 6/25/47, par value $334,620       309,003  
    CWALT 2006-HY12 A2, Variable rate, 8/25/36, par value $167,408       167,572  
    RALI 2006-QS3 1A10, 6.00%, 3/25/36, par value $90,527       90,798  
   
Government and Agency Obligations   US TREASURY NOTE 4.25%, 9/30/12, par value $905,000       936,746  
    US TREASURY NOTE 4.75%, 8/15/17, par value $610,000       644,265  
    FHLMC 30 YR FH 1G2450 Mtg Back FRN 8/1/36, par value $301,332       306,312  
    FNMA 10 YR FN 387608 Mtg Back 4.80%, 9/1/15, par value $216,161       215,750  
    FNMA 30 YR FN 887096 Mtg Back FRN, 7/1/36, par value $187,478       189,038  
   FNMA 30 YR FN 826908 Mtg Back FRN, 8/1/35, par value $150,643       149,000  
    FNMA 30 YR FN 866097 Mtg Back FRN, 2/1/36, par value $133,323       136,395  
    FNMA 30 YR FN 705304 Mtg Back FRN, 6/1/33, par value $123,465       124,315  
    FNMA 30 YR FN 844705 Mtg Back FRN, 12/1/35, par value $113,774       113,946  
   FNMA 30 YR FN 902818 Mtg Back FRN, 11/1/36, par value $103,919       105,855  
    FNMA 30 YR FN 725090 Mtg Back FRN, 11/1/33, par value $102,704       102,713  
    FNMA 30 YR FN 801344 Mtg Back FRN, 10/1/34, par value $87,914       88,316  
    FNMA 30 YR FN 799769 Mtg Back FRN, 11/1/34, par value $86,790       87,171  
    FNMA 30 YR FN 764082 Mtg Back FRN, 1/1/34, par value $78,852       79,494  
    FNMA 30 YR FN 809534 Mtg Back FRN, 2/1/35, par value $75,883       76,599  
    FNMA 30 YR FN 849082 Mtg Back FRN, 1/1/36, par value $72,712       73,317  
    FNMA 30 YR FN 872753 Mtg Back FRN, 6/1/36, par value $71,334       72,686  
    US TREASURY NOTE 4.00%, 9/30/09, par value $50,000       50,797  
    US TREASURY NOTE 3.63%, 10/31/07, par value $15,000       15,148  
   
Participant-Directed Brokerage Accounts   Self-Managed Brokerage Accounts       581,374  
   
Participant Promissory Notes**   Maximum allowable loan -- $50,000      
    Various interest rates -- 5.0% to 10.5%      
    Primarily maturing within 5 years        9,904,024  
 
             $642,363,848  
 

*    Cost value is not required for participant-directed investments.
**   Represents party known to be a party-in-interest to the Alliant Energy Corporation 401(k) Savings Plan.

13

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

FORM 5500, SCHEDULE H, PART IV, LINE 4i - SCHEDULE OF ASSETS (ACQUIRED AND DISPOSED OF WITHIN YEAR)

FOR THE YEAR ENDED DECEMBER 31, 2007

 

  Description of investment    
Identity including maturity date,    
of issue, borrower, lessor rate of interest, collateral, Cost of Proceeds of
or similar party par or maturity value Acquisitions Dispositions

Corporate Bonds   ARMT 2007-1-3A11, 6.20%, 2/25/37   $15,349   $15,088  
    CWALT 2007-OA9-A2, 5.67%, 6/25/47   21,519   22,299  
    CWHL 2006-HYB1-1A1, 5.40%, 3/20/36   110,278   110,278  
    INDYMB 2007-AR5A-1, 6.37%, 5/25/37   3,976   3,926  
    JPMCC 2004-LN2-A1, 4.48%, 7/15/41   3,173   3,242  
    JPMCC 2005-LDP5-A1, 5.04%, 12/15/44   233,798   234,591  
    WMALT 2007-OC1-A2, 5.55%, 1/25/47   25,506   25,506  
    WFMBS 2006-AR12-2A, 6.12%, 9/25/36   26,833   26,612  

14

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

FORM 5500, SCHEDULE H, PART IV

LINE 4j - SCHEDULE OF REPORTABLE TRANSACTIONS

FOR THE YEAR ENDED DECEMBER 31, 2007

Identity Total Total Total Net Adjusted Net
of Party Involved and Number of Value of Number Selling Cost of Gain
Description of Assets Purchases Purchases of Sales Price Assets Sold (Loss)

Single Transaction Exceeds 5% of Value:              
     
None.    

Series of Transactions With Same Broker Exceeds 5% of Value:    
       
None.      

Series of Transactions In Same Security Exceeds 5% of Value:    
       
None.    

Single Transaction With One Broker Exceeds 5% of Value:    
       
None.    

15

SIGNATURES

 

Pursuant to the requirements of the Securities Exchange Act of 1934, the Total Compensation Committee, which administers the Plan, has duly caused this Annual Report to be signed on its behalf by the undersigned, thereunto duly authorized, on this 27th day of June 2008.

 

 

ALLIANT ENERGY CORPORATION

 

401(k) SAVINGS PLAN

 

 

 

/s/ Christopher J. Lindell

 

Christopher J. Lindell

 

 

 

The foregoing person is the Vice President - Shared Services

 

of Alliant Energy Corporation and Alliant Energy Corporate

 

Services, Inc., and the Chairperson of the Alliant Energy

 

Corporation Total Compensation Committee.

16

 

EXHIBIT INDEX TO ANNUAL REPORT ON FORM 11-K

 

ALLIANT ENERGY CORPORATION

401(k) SAVINGS PLAN

 

FOR THE YEAR ENDED DECEMBER 31, 2007

 

 

 

 

 

Page Number in

 

 

Sequentially Numbered

Exhibit No.

Exhibit

Form 11-K

23

Consent of Independent Registered Public Accounting Firm

18

 

17