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                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


                                    FORM 11-K

(Mark One)

/X/   Annual Report Pursuant to Section 15(d) of the Securities Exchange Act of
      1934

For the fiscal year ended DECEMBER 31, 1999

                                       or

/ /   Transition Report Pursuant to Section 15(d) of the Securities Exchange Act
      of 1934

For the transition period from                 to
                                -------------      -------------



                           Commission File No. 1-3548




                    MINNESOTA POWER AND AFFILIATED COMPANIES
                          SUPPLEMENTAL RETIREMENT PLAN
                            (Full Title of the Plan)


                           ---------------------------

                              Minnesota Power, Inc.
                             30 West Superior Street
                          Duluth, Minnesota 55802-2093

                          (Name of issuer of securities
                          held pursuant to the Plan and
                          the address of its principal
                                executive office)

                           ---------------------------


INDEX Page Report of Independent Accountants 1 Statement of Net Assets Available for Plan Benefits - December 31, 1999 and 1998 2 Statement of Changes in Net Assets Available for Plan Benefits - Year Ended December 31, 1999 and 1998 3 Notes to Financial Statements 4 Supplemental Schedules Schedule I: Schedule of Investments Held 12 Schedule II: Schedule of Reportable Transactions in Excess of 5% of Fair Value of Plan Assets 13 Signatures 14

REPORT OF INDEPENDENT ACCOUNTANTS To the Participants and Administrator of the Minnesota Power and Affiliated Companies Supplemental Retirement Plan In our opinion, the accompanying statements of net assets available for plan benefits and the related statements of changes in net assets available for plan benefits present fairly, in all material respects, the net assets available for plan benefits of the Minnesota Power and Affiliated Companies Supplemental Retirement Plan at December 31, 1999 and 1998, and the changes in net assets available for plan benefits for the years then ended, in conformity with accounting principles generally accepted in the United States. 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 of these statements in accordance with generally accepted auditing standards which require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit 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, and evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for the opinion expressed above. Our audit was made for the purpose of forming an opinion on the basic financial statements taken as a whole. The additional information included in Schedules I and II is presented for purposes of additional analysis and is not a required part of the basic financial statements but is additional information required by the Employee Retirement Income Security Act of 1974. Such information has been subjected to the auditing procedures applied in the audit of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole. PRICEWATERHOUSECOOPERS LLP PricewaterhouseCoopers LLP Minneapolis, Minnesota June 9, 2000 1

MINNESOTA POWER AND AFFILIATED COMPANIES SUPPLEMENTAL RETIREMENT PLAN STATEMENT OF NET ASSETS AVAILABLE FOR PLAN BENEFITS Thousands DECEMBER 31, 1999 1998 - --------------------------------------------------------------------------------------------- ASSETS INVESTMENTS, AT FAIR/CONTRACT VALUE Guaranteed Investment Contracts $ 12,362 $ 16,465 Pooled Investment Contracts 6,865 2,464 Minnesota Power, Inc. Common Stock 15,762 18,584 Mutual Fund Securities 70,609 52,050 Money Market Securities 5 16 Loans Receivable from Participants 2,021 2,068 ---------- -------- Total Investments 107,624 91,647 CASH 33 98 ---------- -------- NET ASSETS AVAILABLE FOR PLAN BENEFITS $ 107,657 $ 91,745 ========== ======== - --------------------------------------------------------------------------------------------- The accompanying notes are an integral part of these statements. 2

MINNESOTA POWER AND AFFILIATED COMPANIES SUPPLEMENTAL RETIREMENT PLAN STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR PLAN BENEFITS Thousands YEAR ENDED DECEMBER 31, 1999 1998 - ------------------------------------------------------------------------------------------------ SOURCES OF NET ASSETS Participant Contributions $ 6,239 $ 6,137 Employer Contributions 148 117 Interest Income 1,140 1,146 Dividend Income 4,552 2,376 Net Unrealized Appreciation in Fair Value of Investments 7,386 6,692 Participants' Loan Interest Income 188 182 ---------- -------- 19,653 16,650 APPLICATION OF NET ASSETS Transfers to Retirement Plans (1,107) (479) Benefit Distributions (2,625) (2,287) Administrative Expenses (9) (10) ---------- -------- INCREASE IN NET ASSETS 15,912 13,874 NET ASSETS AVAILABLE FOR PLAN BENEFITS Beginning of Year 91,745 77,871 ---------- -------- End of Year $ 107,657 $ 91,745 ========== ======== - ------------------------------------------------------------------------------------------------ The accompanying notes are an integral part of these statements. 3

MINNESOTA POWER AND AFFILIATED COMPANIES SUPPLEMENTAL RETIREMENT PLAN NOTES TO FINANCIAL STATEMENTS NOTE 1 - DESCRIPTION OF THE PLAN The Minnesota Power and Affiliated Companies Supplemental Retirement Plan (SRP) provides benefits for eligible employees of Minnesota Power, Inc. (Minnesota Power) and two of its subsidiaries, Superior Water, Light and Power Company and MP Affiliated Resources, Inc. (collectively, the Companies). The SRP is a contributory defined contribution plan that is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (ERISA). CONTRIBUTIONS - PARTICIPANT CONTRIBUTIONS to the SRP consist of the following: - FLEXIBLE DOLLAR CONTRIBUTIONS. Flexible dollar contributions for the non-union participants are up to 3 percent of each participant's compensation, up to a maximum compensation of $160,000 in 1999. The contribution is equal to an amount the participant has elected to contribute to the SRP and is included in the participant's before-tax account. - BEFORE-TAX CONTRIBUTIONS. Before-tax contributions consist of salary reduction contributions and results sharing contributions. Total before-tax contributions may not exceed $10,000 in 1999, as permitted under Section 401(k) of the Internal Revenue Code of 1986 (Code). - SALARY REDUCTION CONTRIBUTIONS. Salary reduction contributions are equal to an amount the participant has elected to reduce his or her compensation pursuant to a salary reduction agreement. - RESULTS SHARING CONTRIBUTIONS. Results sharing contributions are equal to the portion (up to 100 percent) of the Results Sharing Award the participant irrevocably agrees to forgo and that, pursuant to the Minnesota Power Results Sharing Program, would otherwise be paid to the participant. - VOLUNTARY CONTRIBUTIONS (AFTER-TAX CONTRIBUTIONS). Each participant is also allowed to make voluntary after-tax contributions to the SRP through payroll deductions or lump-sum contributions. Total voluntary contributions made by a participant for all fiscal years since July 1, 1980 shall not exceed 8.5 percent of the aggregate compensation received for all years since becoming a participant less the amount of voluntary contributions made to either the Minnesota Power and Affiliated Companies Retirement Plan A or Plan B. - ROLLOVERS. Contributions by participants may also be made through rollovers from other qualified plans. - EMPLOYER CONTRIBUTIONS to the SRP consist of non-elective contributions equal to 0.625 percent of each union participant's compensation, up to a maximum compensation of $160,000 in 1999. Employer contributions are included in the participant's before-tax account. VESTING All contributions plus actual earnings are fully vested and nonforfeitable. LOAN PROGRAM The SRP allows participants to borrow money from their SRP accounts. A participant may borrow up to $50,000 or 50 percent of their total before-tax account balances, whichever is less, for up to 5 years for a general purpose loan and 10 years for the acquisition of a primary residence. A fixed interest rate of the prime rate plus 1 percent, but not less than the Minnesota Power Employees Credit Union share secured rate, is charged until the loan is repaid. As loans are repaid, principal and interest amounts are redeposited into the participant's SRP accounts. 4

PARTICIPANT ACCOUNTS Each participant's account is credited with the participant's contribution and their share of the Companies' contributions. Income from the various SRP investment funds is allocated to each participant's account based upon their ownership interest in each fund. Every December participants are required to make an election as to the level of contributions to the SRP for the subsequent year. Funds may be transferred between investment options on a weekly basis with at least 10 days written notice to Minnesota Power's Benefits Accounting and Administration. A brief description of the Plan's investment options follows. For a detailed description of the investment options and respective risk profiles refer to the fund prospectus. - MINNESOTA POWER COMMON STOCK FUND seeks capital appreciation and current income by investing in the common stock of Minnesota Power. - HEARTLAND VALUE FUND seeks long-term capital appreciation by investing primarily in common stocks of companies with market capitalizations of less than $750 million selected on a value basis. - FIDELITY MAGELLAN FUND seeks capital appreciation by investing in securities of domestic, foreign and multinational issuers. - VANGUARD INSTITUTIONAL INDEX FUND seeks to match, as closely as possible, the performance of the Standard & Poor's 500 Composite Stock Price Index, which invests in stocks of large U.S. companies. - VANGUARD SHORT TERM FEDERAL PORTFOLIO invests primarily in U.S. Government agency securities, which are debt obligations issued or guaranteed by agencies or instrumentalities of the U.S. Government. This fund may also invest in U.S. Treasury securities, as well as in repurchase agreements collateralized by the United States. - BLACKROCK FUNDS SMALL CAP GROWTH EQUITY PORTFOLIO seeks long-term capital appreciation by investing in U.S. small capitalization growth companies (market capitalization under $2 billion) which are considered to have above-average earnings growth prospects versus the fund's benchmark, the Russell 2000 Growth Index. - TEMPLETON INSTITUTIONAL FUNDS, INC. FOREIGN EQUITY SERIES seeks long-term capital growth by investing in equity securities of companies located outside the United States and debt obligations of companies and governments located anywhere in the world. - TEMPLETON INSTITUTIONAL FUNDS, INC. EMERGING MARKET SERIES seeks long-term capital growth by investing primarily in equity securities of issuers in countries having developing or emerging markets. - JANUS BALANCED FUND seeks long-term capital growth consistent with preservation of capital and balanced by current income. This fund invests in securities selected primarily for their growth or income potential. - FIXED INCOME FUND consists of guaranteed investment contracts (GICs) with insurance companies and pooled investment contracts (PICs) managed by American Express Trust Company. Each participant's account value is determined on a participation-unit basis. The price per participation-unit was established on April 15, 1999 at $10. The participation-unit value is adjusted each business day to reflect investment results. At December 31, 1999 the Fixed Income Fund consisted of 1,842,970 units with a net value of $19,227,000. - GICs are guaranteed by the issuing insurance company an supported by the insurance industry, and not guaranteed by the federal government. - AMERICAN EXPRESS TRUST INCOME FUND I is an actively managed, diversified pool of stable value contracts of varying maturity, size and yield. This fund seeks to preserve principal and income while maximizing current income by investing in pooled insurance investment contracts, bank investment contracts and stable value contracts regulated by the Securities and Exchange Commission and federal and state bank regulators. 5

While participants are active employees, they may withdraw money as a loan from their before-tax account. After age 59 1/2, participants may withdraw the full amount of their before-tax account. After-tax accounts may be withdrawn at specified times during the year by participants of any age. When participants terminate employment, become disabled or die, they or their beneficiaries may elect to receive the vested amount of all their SRP accounts. Upon retirement participants may elect to transfer the vested amount of their SRP account balances to the Minnesota Power and Affiliated Companies Retirement Plan A or Plan B. Minnesota Power maintains the participants' records and issues a quarterly report to each participant showing the status of individual accounts. At December 31, 1999 there were 1,673 participants in the SRP. ADMINISTRATION The SRP is administered by the Employee Benefit Plans Committee (Committee). The address of the Committee is 30 West Superior Street, Duluth, Minnesota 55802-2093. The responsibility of the Committee includes the determination of compliance with the SRP's eligibility requirements as well as the administration and payment of benefits all in a manner consistent with the terms of the SRP and applicable law. The Committee has the authority to designate persons to carry out fiduciary responsibilities (other than trustee responsibilities) under the SRP. The Committee has the power to appoint an investment manager or managers. Administration fees and expenses of agents, outside experts, consultants, and investment managers are paid by the Companies or the SRP. The Committee may from time to time establish, modify and repeal rules for the administration of the SRP as may be necessary to carry out the purpose of the SRP. Members of the Committee receive no compensation for their services with respect to the SRP. As of June 1, 2000 the members of the Committee, all employees of Minnesota Power, and their respective titles are as follows: Name Title ---------------------- ------------------------------------ Robert D. Edwards Executive Vice President and President - Minnesota Power Electric (1) David G. Gartzke Senior Vice President - Finance and Chief Financial Officer Philip R. Halverson Vice President, General Counsel and Secretary Brenda J. Flayton Vice President - Human Resources Claudia R. Scott Welty Vice President - Information Technology Mark A. Schober Controller Donald J. Shippar Chief Operating Officer - Minnesota Power Electric Roger P. Engle Vice President - Minnesota Power Electric and President and Chief Operating Officer - Superior Water, Light and Power Company Lori A. Collard President - Electric Outlet, Inc. Alan R. Hodnik Manager - Laskin Energy Center Jeweleon W. Tuominen Manager - Executive Compensation and Employee Benefits Deborah Amberg Senior Attorney - ---------------------- (1) Committee Chairman North Shore Bank of Commerce is retained as Trustee (Trustee) for the SRP. The Trustee's main office is located at 131 West Superior Street, Duluth, Minnesota 55802. The Trustee carries blanket bond insurance in the amount of $2 million. 6

PLAN TERMINATION The Companies reserve the right to reduce, suspend or discontinue their contributions at any time or to terminate the SRP subject to the provisions of ERISA and the Code. In the event of SRP termination, all of the account balances of the participants will be fully vested and nonforfeitable, and distributions will be made in accordance with the terms of the SRP. NOTE 2 - SUMMARY OF ACCOUNTING POLICIES The SRP uses the accrual basis of accounting and, accordingly, reflects income in the year earned and expenses when incurred. Mutual funds, money market securities and Minnesota Power common stock are reported at fair value based on quoted market prices. GIC and PIC amounts are reported at contract value which approximates fair value and represents the purchase price of the contract plus accrued interest. Participants' loans are reported at estimated fair value which represents outstanding principal and any related accrued interest. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to (i) make estimates and assumptions that affect the reported amounts of assets and liabilities, (ii) disclose contingent liabilities at the date of the financial statements and (iii) report amounts of revenue and expense during the reporting period. Actual results could differ from those estimates. The Plan presents in the statement of changes in net assets available for plan benefits the net appreciation (depreciation) in the fair value of its investment which consists of the realized gains or losses and the unrealized appreciation (depreciation) on those investments. NOTE 3 - FEDERAL INCOME TAX STATUS A favorable determination letter dated December 12, 1995 was obtained from the Internal Revenue Service stating that the SRP, as amended and restated effective January 1, 1992, qualifies as a profit sharing plan under Section 401(a) of the Code. NOTE 4 - GUARANTEED INVESTMENT CONTRACTS There are no reserves against the contract value for credit risk of the contract issuer or otherwise. The crediting interest rate is agreed upon with the issuer upon initiation of the contract. Contract Value Crediting December 31, Due Interest Rate 1999 1998 - ----------------------------------------------------------------------------------------------------------- Thousands Aetna Life Insurance Company 1999 6.06% $ 2,695 Provident Mutual Insurance Company 1999 5.80% 2,130 SunAmerica Life Insurance Company 2000 6.00% $ 2,279 2,150 Jackson National Life Insurance Company 2000 6.30% 3,580 3,368 Monumental Life Insurance Company 2001 6.67% 2,142 2,008 Protective Life Insurance Company 2001 6.17% 2,217 2,089 Continental Assurance Company 2002 5.88% 2,144 2,025 -------- -------- $ 12,362 $ 16,465 ======== ======== Average Yield 6.38% 6.51% 7

NOTE 5 - CHANGES IN SRP ASSETS FOR PARTICIPANT DIRECTED ACCOUNTS Thousands The table below summarizes the changes in SRP assets for each investment fund for the year ended December 31, 1999. Fixed Income Fund Mutual Fund Securities --------- --------------------------------------------------- Vanguard Vanguard Heartland Fidelity Institutional Short Term GICs and Value Magellan Index Federal PICs Fund Fund Fund Portfolio Sources of Net Assets Participant Contributions $ 826 $ 359 $ 846 $ 1,443 $ 295 Employer Contributions 33 8 20 28 5 Interest Income 1,139 Dividend Income 13 1,729 307 101 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments 952 2,313 2,621 (61) Participants' Loan Repayments, Including Interest 146 65 155 175 61 --------- -------- --------- -------- ------- 2,144 1,397 5,063 4,574 401 Application of Net Assets Transfers to Retirement Plans (1,107) Benefit Distributions (847) (54) (446) (345) (44) Loans to Participants (271) (39) (108) (69) (12) Administrative Expenses (9) --------- -------- --------- -------- ------- Increase (Decrease) in Net Assets (90) 1,304 4,509 4,160 345 Net Transfers 376 (938) (73) 4 (255) Net Assets Available for Plan Benefits Beginning of Year 18,942 4,542 16,613 13,113 1,549 --------- -------- --------- -------- ------- End of Year $ 19,228 $ 4,908 $ 21,049 $ 17,277 $ 1,639 ========= ======== ========= ======== ======= 8

Mutual Fund Securities (Continued) ------------------------------------------------------------------- BlackRock Templeton Templeton Funds Small Institutional Institutional Cap Growth Funds, Inc. Janus Funds, Inc. Equity Foreign Balanced Emerging Portfolio Equity Series Fund Market Series Sources of Net Assets Participant Contributions $ 352 $ 183 $ 1,395 $ 134 Employer Contributions 9 3 25 3 Interest Income Dividend Income 987 134 334 24 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments 2,809 496 1,551 1,037 Participants' Loan Repayments, Including Interest 61 23 168 25 ------- ------- -------- ------- 4,218 839 3,473 1,223 Application of Net Assets Transfers to Retirement Plans Benefit Distributions (77) (46) (202) (34) Loans to Participants (47) (24) (124) (9) Administrative Expenses ------- ------- -------- ------- Increase (Decrease) in Net Assets 4,094 769 3,147 1,180 Net Transfers (431) 4 735 4 Net Assets Available for Plan Benefits Beginning of Year 5,317 2,232 6,800 1,886 ------- ------- -------- ------- End of Year $ 8,980 $ 3,005 $ 10,682 $ 3,070 ======= ======= ======== =======

Minnesota Loans Power Receivable Common from Stock Participants Total Sources of Net Assets Participant Contributions $ 406 $ 6,239 Employer Contributions 14 148 Interest Income 1 1,140 Dividend Income 923 4,552 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments (4,332) 7,386 Participants' Loan Repayments, Including Interest 97 $ (788) 188 -------- -------- --------- (2,891) (788) 19,653 Application of Net Assets Transfers to Retirement Plans (1,107) Benefit Distributions (469) (61) (2,625) Loans to Participants (99) 802 0 Administrative Expenses (9) -------- -------- --------- Increase (Decrease) in Net Assets (3,459) (47) 15,912 Net Transfers 574 0 Net Assets Available for Plan Benefits Beginning of Year 18,683 2,068 91,745 -------- -------- --------- End of Year $ 15,798 $ 2,021 $ 107,657 ======== ======== ========= - ------------ Balances include $16 of short-term money market securities which were being held for participant distributions and $98 in cash which was being held to be invested in Minnesota Power Common Stock. Balances include $5 of short-term money market securities which were being held for participant distributions and $33 in cash which was being held to be invested in Minnesota Power Common Stock. 9

NOTE 5 - CHANGES IN SRP ASSETS FOR PARTICIPANT DIRECTED ACCOUNTS Thousands The table below summarizes the changes in SRP assets for each investment fund for the year ended December 31, 1998. Fixed Income Fund Mutual Fund Securities ------ --------------------------------------------------------- Vanguard Vanguard Heartland Fidelity Institutional Short Term GICs and Value Magellan Index Federal PICs Fund Fund Fund Portfolio Sources of Net Assets Participant Contributions $ 700 $ 860 $ 655 $ 1,294 $ 147 Employer Contributions 55 9 8 13 1 Interest Income 1,146 Dividend Income 102 761 250 73 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments (661) 3,378 2,471 17 Participants' Loan Repayments, Including Interest 311 50 124 104 10 --------- -------- --------- -------- ------- 2,212 360 4,926 4,132 248 Application of Net Assets Transfers to Retirement Plans (479) Benefit Distributions (1,435) (80) (211) (116) (14) Loans to Participants (1,066) Administrative Expenses (10) --------- -------- --------- -------- ------- Increase (Decrease) in Net Assets (778) 280 4,715 4,016 234 Net Transfers 1,304 (344) (368) 448 260 Net Assets Available for Plan Benefits Beginning of Year 18,416 4,606 12,266 8,649 1,055 --------- -------- --------- -------- ------- End of Year $ 18,942 $ 4,542 $ 16,613 $ 13,113 $ 1,549 ========= ======== ========= ======== ======= 10

Mutual Fund Securities (Continued) --------------------------------------------------------------------- BlackRock Templeton Templeton Funds Small Institutional Institutional Cap Growth Funds, Inc. Janus Funds, Inc. Equity Foreign Balanced Emerging Portfolio Equity Series Fund Market Series Sources of Net Assets Participant Contributions $ 782 $ 246 $ 849 $ 297 Employer Contributions 8 2 7 3 Interest Income Dividend Income 150 147 43 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments 356 30 1,337 (448) Participants' Loan Repayments, Including Interest 60 26 40 26 ------- ------- -------- ------- 1,206 454 2,380 (79) Application of Net Assets Transfers to Retirement Plans Benefit Distributions (35) (10) (31) (23) Loans to Participants Administrative Expenses ------- ------- -------- ------- Increase (Decrease) in Net Assets 1,171 444 2,349 (102) Net Transfers (584) 12 171 (240) Net Assets Available for Plan Benefits Beginning of Year 4,730 1,776 4,280 2,228 ------- ------- -------- ------- End of Year $ 5,317 $ 2,232 $ 6,800 $ 1,886 ======= ======= ======== =======

Minnesota Loans Power Receivable Common from Stock Participants Total Sources of Net Assets Participant Contributions $ 307 $ 6,137 Employer Contributions 11 117 Interest Income 1,146 Dividend Income 850 2,376 Net Unrealized Appreciation (Depreciation) in Fair Value of Investments 212 6,692 Participants' Loan Repayments, Including Interest 275 $ (844) 182 -------- -------- --------- 1,655 (844) 16,650 Application of Net Assets Transfers to Retirement Plans (479) Benefit Distributions (296) (36) (2,287) Loans to Participants 1,066 0 Administrative Expenses (10) -------- -------- --------- Increase (Decrease) in Net Assets 1,359 186 13,874 Net Transfers (659) 0 Net Assets Available for Plan Benefits Beginning of Year 17,983 1,882 77,871 -------- -------- --------- End of Year $ 18,683 $ 2,068 $ 91,745 ======== ======== ========= - ------------ Balances include $54 of short-term money market securities of which $43 was being held to be invested in Minnesota Power Common Stock and the balance for participant distributions. Balances also include $11 in cash. Balances include $16 of short-term money market securities which were being held for participant distributions and $98 in cash which was being held to be invested in Minnesota Power Common Stock. 11 Schedule I MINNESOTA POWER AND AFFILIATED COMPANIES SUPPLEMENTAL RETIREMENT PLAN SCHEDULE OF INVESTMENTS HELD AS OF DECEMBER 31, 1999 Thousands (a) (b) (c) (d) (e) Fair/ Description of Contract Identity of Issuer Investment Cost Value - ------------------------------------------------------------------------------------------------------------------------------------ Guaranteed Investment Contracts SunAmerica Life Insurance Company GIC - 6.00% due 2000 $ 2,279 $ 2,279 Jackson National Life Insurance Company GIC - 6.30% due 2000 3,580 3,580 Monumental Life Insurance Company GIC - 6.67% due 2001 2,142 2,142 Protective Life Insurance Company GIC - 6.17% due 2001 2,217 2,217 Continental Assurance Company GIC - 5.88% due 2002 2,144 2,144 -------- ---------- Total Guaranteed Investment Contracts 12,362 12,362 -------- ---------- Pooled Investment Contract American Express Trust Income Fund I PIC - 134 Shares 6,865 6,865 -------- ---------- * Minnesota Power, Inc. Common Stock - 932 Shares 13,277 15,762 -------- ---------- Mutual Fund Securities Heartland Value Fund Mutual Fund - 134 Shares 4,045 4,908 Fidelity Magellan Fund Mutual Fund - 154 Shares 13,137 21,048 Vanguard Institutional Index Fund Mutual Fund - 129 Shares 10,185 17,277 Vanguard Short Term Federal Portfolio Mutual Fund - 166 Shares 1,639 1,639 BlackRock Small Cap Growth Equity Portfolio Mutual Fund - 274 Shares 5,937 8,980 Templeton Institutional Fund Foreign Equity Series Mutual Fund - 140 Shares 2,605 3,005 Janus Balanced Fund Mutual Fund - 457 Shares 7,850 10,682 Templeton Institutional Fund Emerging Market Series Mutual Fund - 238 Shares 2,656 3,070 -------- ---------- Total Mutual Funds 48,054 70,609 -------- ---------- Money Market Securities Dreyfus Institutional Government Securities Fund Money Market - Floating Interest Rate with No Maturity Date 5 5 -------- ---------- * Minnesota Power, Inc. Loans Receivable from Participants - 7% to 10% - 2,021 -------- ---------- Total Investments $ 80,563 $107,624 ======== ======== - ---------------------- * Party-in-interest 12

Schedule II MINNESOTA POWER AND AFFILIATED COMPANIES SUPPLEMENTAL RETIREMENT PLAN SCHEDULE OF REPORTABLE TRANSACTIONS IN EXCESS OF 5% OF FAIR VALUE OF PLAN ASSETS FOR THE YEAR ENDED DECEMBER 31, 1999 Dollars in Thousands (a) (b) (c) (d) (e) (f) (g) (h) (i) Current Net Identity of Description Purchase Selling Lease Expense Cost of Value Gain or Party Involved of Asset Price Price Rental Incurred Asset of Asset (Loss) - ------------------------------------------------------------------------------------------------------------------- Dreyfus Institutional Money Government Market Securities Fund Securities $9,684 - - - - $9,684 - Dreyfus Institutional Money Government Series Market Securities Fund Securities - $9,696 - - $9,696 $9,696 - American Express Pooled Trust Income Investment Fund I Contract $8,086 - - - - $8,086 - American Express Pooled Trust Income Investment Fund I Contract - $3,901 - - $3,901 $3,901 - Minnesota Power Common Stock $3,114 - - - - $3,114 - Minnesota Power Common Stock - $1,604 - - $1,619 $1,619 $(15) 13

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the Employee Benefit Plans Committee has duly caused this annual report to be signed on its behalf by the undersigned hereunto duly authorized. Minnesota Power and Affiliated Companies Supplemental Retirement Plan ---------------------------------------- (Name of Plan) June 13, 2000 By R.D. Edwards ---------------------------------------- R.D. Edwards Chairman, Employee Benefit Plans Committee 14

INDEX TO EXHIBITS Exhibit - ------- a - Consent of Independent Accountants

Exhibit a CONSENT OF INDEPENDENT ACCOUNTANTS We hereby consent to the incorporation by reference in the Registration Statement on Form S-8 (No. 333-26755) of the Minnesota Power and Affiliated Companies Supplemental Retirement Plan of our report dated June 9, 2000 appearing on page 1 of this Annual Report of the Minnesota Power and Affiliated Companies Supplemental Retirement Plan on Form 11-K for the year ended December 31, 1999. PRICEWATERHOUSECOOPERS LLP PricewaterhouseCoopers LLP Minneapolis, Minnesota June 13, 2000