424B5

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and are not soliciting an offer to buy these securities in any state where the offer and sale is not permitted.

We are offering $ aggregate principal amount of our Senior Notes, % Series Due November 1, . We will pay interest on the notes semi-annually in arrears on May 1 and November 1 of each year, beginning May 1, 2014.

We may redeem some or all of the notes at any time before their maturity date at our option at the redemption prices described under “Description of the Notes—Optional Redemption” in this prospectus supplement.

Until we retire all of our first mortgage bonds, a series of our collateral bonds will secure the notes. On the date we retire all of our first mortgage bonds, the collateral bonds will cease to secure the notes and, at our option, the notes will either (1) become our unsecured general obligations and rank on a parity with our other senior unsecured indebtedness, or (2) be secured by substitute collateral bonds secured by a substitute mortgage indenture.

The notes are a new issue of securities with no established trading market. We do not intend to list the notes on any securities exchange.

See “Risk Factors” beginning on page 7 of our Annual Report on Form 10-K for the year ended December 31, 2012 for a discussion of certain risks that prospective investors should consider before investing in our notes.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these notes or determined if this prospectus supplement and the accompanying prospectus are truthful or complete. Any representation to the contrary is a criminal offense.

The underwriters are severally offering the notes, subject to the prior receipt and acceptance of the notes by the underwriters and their right to reject any order in whole or in part.

The underwriters expect to deliver the notes through the book-entry facilities of The Depository Trust Company on or about November , 2013.

This document has two parts. The first part is the prospectus supplement, which describes the specific terms of this offering. The second part is the accompanying prospectus, which provides more general information, some of which may not apply to this offering. You should read the entire prospectus supplement, as well as the accompanying prospectus and the documents incorporated by reference that are described under “Summary—Where You Can Find More Information” in the accompanying prospectus. In the event that the description of the offering in this prospectus supplement is inconsistent with the accompanying prospectus, you should rely on the information contained in this prospectus supplement.

You should rely only on the information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus and any related free writing prospectus we file with the Securities and Exchange Commission (the “SEC”). We have not, and the underwriters have not, authorized anyone to provide you with different information. We are not, and the underwriters are not, making an offer of the notes in any jurisdiction which does not permit their offer or sale. You should not assume that the information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or any related free writing prospectus we file with the SEC is accurate as of any date other than its respective date.

We are a Wisconsin corporation and a wholly owned subsidiary of Integrys Energy Group, Inc. We began operations in 1883. We are a regulated electric and natural gas utility company serving an approximate 12,000 square mile service territory in northeastern Wisconsin and an adjacent portion of Michigan’s Upper Peninsula. At December 31, 2012, we served approximately 443,000 regulated electric utility customers and approximately 321,000 regulated natural gas utility customers. We also provide wholesale electric service to various customers, including municipal utilities, electric cooperatives, energy marketers, other investor-owned utilities and municipal joint action agencies for resale. Our executive offices are at 700 North Adams Street, P.O. Box 19001, Green Bay, Wisconsin 54307-9001. Our telephone number is 800-450-7260.

The notes offered pursuant to this prospectus supplement and the accompanying prospectus are solely our obligations. Integrys Energy Group, Inc. is not obligated to make any payment of principal or interest on the notes.

For purposes of this prospectus supplement and the accompanying prospectus, unless the context otherwise indicates, when we refer to “us,” “we,” “ours,” or the “company” we are describing Wisconsin Public Service Corporation together with its subsidiary.

Please read the following information concerning the notes in conjunction with the statements under “Description of the Senior Debt Securities” in the accompanying prospectus. The following information supplements those statements and supersedes any statements in the prospectus that are inconsistent with it.

Our summary financial information as of and for the periods indicated is set forth below. The annual information set forth below for each of the three fiscal years in the period ended December 31, 2012 was derived from our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2012, which is incorporated in the accompanying prospectus by reference. The financial information as of and for the period ended September 30, 2013 was derived from our unaudited quarterly financial statements included in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2013, which is incorporated in the accompanying prospectus by reference. For a more detailed discussion of the consolidated financial data, see also “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the year ended December 31, 2012 and in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2013.

The ratio of earnings to fixed charges for each of the periods indicated are as follows:

The Depository Trust Company will act as securities depositary for the Senior Notes, % Series Due November 1, . We will issue the notes only as fully-registered securities registered in the name of The Depository Trust Company’s partnership nominee, Cede & Co. (or such other nominee as may be designated by an authorized representative of The Depository Trust Company). We will deposit the notes with the senior trustee as custodian for The Depository Trust Company. We will issue one or more fully-registered global certificates representing the total aggregate principal amount of the notes.

The laws of some jurisdictions require that certain purchasers of securities take physical delivery of securities in definitive form. Such laws may impair the ability to transfer beneficial interests in the notes as represented by a global certificate.

For additional information relating to The Depository Trust Company and the book-entry issuance system, see “Description of the Senior Debt Securities—Book-Entry Securities” in the accompanying prospectus.

We intend to use the net proceeds from the sale of the notes for one or more of the following purposes: (1) to permanently finance $250 million of the $391.6 million cost we incurred in March 2013 to acquire the Fox Energy Center, a 593-megawatt combined-cycle electric generating facility in Wisconsin, and related acquisition costs, including the repayment of our $200 million term credit facility that we entered into to temporarily finance that acquisition; (2) to refund outstanding long-term debt as it matures, including our $125 million of 4.80% Senior Notes due December 1, 2013; (3) to pay costs of construction or acquisition of other utility capital assets; (4) to retire short-term indebtedness incurred for construction or acquisition of other utility capital assets and other corporate utility purposes; or (5) for other general corporate utility purposes.

The average interest rate on our term credit facility as of November 8, 2013 was 0.77% and it matures on December 31, 2013. On November 8, 2013, we had an aggregate of approximately $84.5 million of short-term borrowings other than under our term credit facility, which had maturities of up to 21 days and a weighted average annual interest rate of 0.16%.

Under an order dated February 22, 2013, the Public Service Commission of Wisconsin approved our request to incur additional short-term borrowings of up to $450 million to permit us to temporarily finance the acquisition of the Fox Energy Center. Our authority to increase our short-term borrowings under that order expires on the earlier of ten days after permanent financing has been obtained or December 31, 2013. We therefore expect to prepay the full $200 million outstanding under our term credit facility immediately following the closing.

Deutsche Bank Securities Inc., Mizuho Securities USA Inc., Scotia Capital (USA) Inc., Goldman, Sachs & Co., Mitsubishi UFJ Securities (USA), Inc., and U.S. Bancorp Investments, Inc. are acting as representatives of each of the underwriters named below. Subject to the terms and conditions of the underwriting agreement, dated the date of this prospectus supplement, we have agreed to sell to the underwriters, and each of the underwriters has severally agreed to purchase, the principal amount of notes set forth opposite the underwriter’s name in the table below:

Subject to the terms and conditions of the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the notes sold under the underwriting agreement if any of the notes are purchased. In the event of a default by an underwriter, the underwriting agreement provides that, in certain circumstances, the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated. The underwriters will sell the notes to the public when and if the underwriters buy the notes from us.

We have agreed to indemnify the several underwriters against certain liabilities, including liabilities under the Securities Act of 1933, as amended.

The notes constitute a new issue of securities with no established trading market. We do not intend to list the notes on any securities exchange. The underwriters have advised us that they intend to make a market in the notes, but the underwriters have not obligated themselves to do so and may discontinue market making at any time without notice. We can give you no assurance as to the liquidity of the trading market for the notes.

The underwriters will initially offer the notes at the initial public offering price set forth on the cover of this prospectus supplement. The underwriters may sell notes to securities dealers at a discount from the initial public offering price of up to 0. % of the principal amount of the notes. Any such securities dealers may resell any notes purchased from the underwriters to certain other brokers or dealers at a discount from the initial public offering price of up to 0. % of the principal amount of the notes. If the underwriters do not sell all of the notes at the initial offering price, the underwriters may change the offering price and other selling terms. The offering of the notes by the underwriters is subject to the prior receipt and acceptance of the notes by the underwriters and to their right to reject any order, in whole or in part.

The following table shows the underwriting discount to be paid by us to the underwriters in connection with this offering.

We estimate that our share of the total expenses of the offering, excluding underwriting discounts, will be approximately $650,000.

In order to facilitate the offering of the notes, the underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the notes. Specifically, the underwriters may over-allot in connection with the offering, creating a short position in the notes for their own accounts. In addition, to cover short positions or to stabilize the price of the notes, the underwriters may bid for and purchase the notes in the open market. Any of these activities may stabilize or maintain the market price of the notes above independent market levels. The underwriters are not required to engage in these activities and may end any of these activities at any time. The underwriters may effect these transactions in the over-the-counter market or otherwise.

The underwriters may impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased notes sold by or for the account of such underwriter in stabilizing or short covering transactions.

We expect that the delivery of the notes will be made against payment therefor on or about the closing date specified on the cover of this prospectus supplement, which will be the fifth business day following the date hereof. Under Rule 15c6-1 of the Securities and Exchange Commission under the Securities Exchange Act of 1934, as amended, trades in the secondary market generally are required to settle in three business days, unless the parties to the trade expressly agree otherwise. Accordingly, purchasers who wish to trade the notes before November , 2013 will be required, by virtue of the fact that any such trade would otherwise settle in more than three business days, to specify an alternate settlement cycle at the time of any such trade to prevent a failed settlement and should consult their own advisor with respect to these matters.

Affiliates of two of the underwriters, Scotia Capital (USA) Inc. and U.S. Bancorp Investments, Inc., are lenders under the $200 million term credit facility that we entered into to temporarily finance our acquisition of the Fox Energy Center. A portion of the net proceeds of this offering will be used to repay all of the outstanding loans under that facility. See “Use of Proceeds.” As a result, each such affiliate will receive, from the net proceeds of this offering, a repayment under that facility of $50 million in principal amount, plus any accrued and unpaid interest due on such amount at the time of repayment. Such payments would constitute a “conflict of interest” under Rule 5121 of the Financial Industry Regulatory Authority, Inc. (“FINRA”). Consequently, this offering will be conducted in accordance with the requirements of FINRA Rule 5121.

Certain of the underwriters and their affiliates have from time to time provided, and may in the future provide, investment banking and other services to us, our parent company or other subsidiaries of our parent company in the ordinary course of business, for which they have received or in the future may receive customary fees and expenses. Affiliates of certain of the underwriters are lenders under our revolving credit facilities, and an affiliate of U.S. Bancorp Investments, Inc. is the senior trustee under the senior indenture and the mortgage trustee under the mortgage indenture.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. If

any of the underwriters or their affiliates has a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters or their affiliates may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments

Our counsel, Foley & Lardner LLP, Milwaukee, Wisconsin, will issue its opinion as to the validity of the notes being issued. Schiff Hardin LLP, Washington, D.C., will issue an opinion for the underwriters as to certain matters relating to the offering of the notes.

We intend to offer up to $500,000,000 of one or more series of our senior debt securities at such times and on such terms as we may determine in the light of market conditions and other factors. The senior debt securities will be secured by a pledge of first mortgage bonds issued under our mortgage indenture. This pledge will remain in effect so long as we have other first mortgage bonds outstanding. Upon the retirement of all other first mortgage bonds, the pledge will be released. The specific designation, aggregate principal amount, purchase price, maturity, rate and time of payment of interest, and the redemption terms or other specific terms of the senior debt securities will be set forth in an accompanying prospectus supplement, together with the terms of offering of the senior debt securities. See also “Description of Senior Debt Securities.”

We may sell the senior debt securities to or through underwriters and also may sell the senior debt securities directly to other purchasers or through agents. The prospectus supplement will set forth the names of any underwriters or agents involved in the sale of the senior debt securities, the nature of the underwriting arrangements, the principal amounts to be purchased by the underwriters and the compensation of the underwriters or agents.

This prospectus may not be used to sell any of these securities unless accompanied by a prospectus supplement.

See “Risk Factors” in the accompanying prospectus supplement or in such other document we refer you to in the accompanying prospectus supplement for a discussion of certain risks that prospective investors should consider before investing in our senior debt securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus is a part of the registration statement that we filed with the Securities and Exchange Commission. You should read this prospectus and any accompanying prospectus supplement together with the more detailed information regarding our company, our securities and our financial statements and notes to those statements that appear elsewhere in this prospectus or that we incorporate in this prospectus by reference.

You should rely only on the information contained in, or incorporated by reference in, this prospectus and in any accompanying prospectus supplement. We have not authorized anyone to provide you with information different from that contained in, or incorporated by reference in, this prospectus or any prospectus supplement. You should not assume that the information in this prospectus or any prospectus supplement is accurate as of any date other than the date on the front of the prospectus or prospectus supplement, as applicable.

SUMMARY

This summary highlights selected information from this prospectus and may not contain all of the information that is important to you. To understand the terms of our securities, you should carefully read this prospectus with the accompanying prospectus supplement. Together these documents will give the specific terms of the securities we are offering. You should also read the documents we have incorporated by reference into this prospectus and the accompanying prospectus supplement for information on us and our financial statements.

The Offering


Company	Wisconsin Public Service Corporation

Securities Being Offered	Not exceeding $500,000,000 Senior Debt Securities

The Company

Business	Regulated electric and natural gas utility

Service Area	Approximately 11,000 square miles in northeastern Wisconsin and an adjacent portion of the Upper Peninsula of Michigan

Sources of Total Operating Revenues for the Year Ended December 31, 2012	80% Electric; 20% Natural Gas

Customers (approximate) at December 31, 2012	Electric-443,000; Natural Gas-321,000

Sources of Electric Supply in 2012	Owned Generation Units
	Coal	51.1	%
	Wind	2.3	%
	Hydroelectric	1.2	%
	Natural gas, fuel oil and tire derived	1.2	%

	Total owned	55.8	%

	Purchased Power
	Nuclear	18.3	%
	Natural gas	20.0	%
	Hydroelectric	2.7	%
	Wind	1.5	%
	Other (including Midwest Independent Transmission System Operator, Inc.)	15.0	%

	Total purchased power	57.5	%

	Opportunity Sales	(13.3	%)

Ratios of Earnings to Fixed Charges (Unaudited) *


Year Ended December 31,
2008	2009	2010	2011	2012
5.2	4.2	4.7	4.8	5.4

In computing the ratios, earnings represent income from continuing operations before federal and state income taxes and fixed charges, less undistributed earnings of less then 50% owned affiliates. Fixed charges represent interest expense, allowance for borrowed funds used during construction and the estimated interest component of rentals.

Where You Can Find More Information

We file annual, quarterly and current reports and other information with the Securities and Exchange Commission. You may read and copy any document we file at the Commission’s public reference room at 100 F Street, N.E., Washington, D.C., 20549. Please call the Commission at 1-800-SEC-0330 for further information on the public reference room. Our Securities and Exchange Commission filings are also available to the public at the Commission’s web site at http://www.sec.gov.

We have filed with the Commission a Registration Statement on Form S-3, including exhibits, under the Securities Act of 1933 with respect to the securities offered by this prospectus. This prospectus is part of that registration statement, but does not contain all of the information contained in the registration statement or its exhibits, certain parts of which we have omitted in accordance with the rules and regulations of the Commission. For further information, you should refer to the registration statement and its exhibits. Any statements contained in this prospectus concerning the provisions of any document filed as an exhibit to the registration statement or otherwise filed with the Commission are not necessarily complete. You should refer to the copy of the document filed with the Commission for a more complete description of the matter involved.

The Securities and Exchange Commission allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and later information that we file with the Commission will automatically update and supersede this information. We incorporate by reference the documents listed below (our File No. is 1-3016) and any future filings made with the Securities and Exchange Commission under Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934 until our offering is completed:

Our Annual Report on Form 10-K for the year ended December 31, 2012, which was filed on March 1, 2013.

You may request a copy of these filings, at no cost, by writing to or telephoning us at the following address:

Wisconsin Public Service Corporation

Attn: Secretary

130 East Randolph Street

Chicago, Illinois 60601-6207

(312) 240-4303

Our reports are also available on the website of our parent company, Integrys Energy Group, Inc., located at http://www.integrysgroup.com/investor/, and can be accessed by selecting “SEC Filings.”

We are a wholly owned subsidiary of Integrys Energy Group, Inc. The senior debt securities offered pursuant to this prospectus, however, are solely our obligations, and Integrys Energy Group is not obligated to make any payments of principal or interest on our senior debt securities.

We are a regulated electric and natural gas utility that generates electricity and distributes electricity and natural gas in northeastern Wisconsin and an adjacent portion of the Upper Peninsula of Michigan. As of December 31, 2012, our regulated electric utility operations served approximately 443,000 residential, commercial and industrial, wholesale and other customers. Wholesale electric service is provided to various customers, including municipal utilities, electric cooperatives, energy marketers, other investor-owned utilities and municipal joint action agencies. As of December 31, 2012, our regulated natural gas utility served approximately 321,000 residential, commercial and industrial, transportation and other customers. In 2012, electric revenues accounted for 80.4% of total revenues, while natural gas revenues accounted for 19.6% of total revenues. Retail revenues accounted for 86.4% of our 2012 total electric revenues, while wholesale revenues accounted for 13.6% of our 2012 total electric revenues. We were incorporated under the laws of the State of Wisconsin in 1883. Our executive offices are at 700 North Adams Street, P.O. Box 19001, Green Bay, Wisconsin 54307. Our telephone number is 800-450-7260.

The Public Service Commission of Wisconsin regulates our Wisconsin retail utility rates and service and any issuance of securities by us. The Michigan Public Service Commission regulates our Michigan retail utility rates and service. The Federal Energy Regulatory Commission regulates our wholesale electric rates, hydroelectric projects and certain other matters. We must also comply with mandatory electric system reliability standards developed by the North American Electric Reliability Corporation, the electric reliability organization certified by the Federal Energy Regulatory Commission. The Midwest Reliability Organization is responsible for the enforcement of the North American Electric Reliability Corporation’s standards for us. We are also subject to state and federal environmental regulation and to limited regulation by local authorities.

Unless otherwise specified in the applicable prospectus supplement, we will use the net proceeds from the sale of the senior debt securities to (i) fund the purchase of the Fox Energy Center, a 593-megawatt combined-cycle electric generating facility in Wisconsin, and related acquisition costs, (ii) retire short-term indebtedness issued to temporarily finance the acquisition, (iii) refund outstanding short-term indebtedness incurred for purposes other than the acquisition, (iv) refund outstanding long-term debt and (v) pay the cost of construction or acquisition of other capital assets. Any remaining proceeds will be used for other general corporate utility purposes.

The description of the senior debt securities offered in the accompanying prospectus supplement modifies the following description. Please read both descriptions. The following is a summary of the material provisions of the senior indenture. This summary does not purport to be complete and is qualified in its entirety by the more detailed provisions of the senior indenture and supplemental indentures, which are incorporated by reference in this prospectus.

General: We will issue from time to time, in one or more series, senior debt securities under a Trust Indenture dated as of December 1, 1998 between us and U.S. Bank National Association (successor to Firstar Bank Milwaukee, N.A., National Association), as supplemented and amended by any supplemental indentures, which we refer to collectively in this prospectus as the “senior indenture”. In this prospectus, we refer to U.S. Bank National Association and any successor trustee under the senior indenture as the senior trustee. The senior indenture is an exhibit to the registration statement.

Until the release date, the senior debt securities will be secured by one or more series of our first mortgage bonds issued and delivered to the senior trustee. See “Security; Release Date” below. These first mortgage bonds, or the collateral bonds, will be issued under the First Mortgage and Deed of Trust dated January 1, 1941 from us to U.S. Bank National Association (successor to First Wisconsin Trust Company), as supplemented and amended by any supplemental indentures, which we refer to collectively as the “mortgage indenture” in this prospectus. In this prospectus, we refer to U.S. Bank National Association and any successor trustee under the mortgage indenture as the “mortgage trustee”. The mortgage indenture is an exhibit to the registration statement.

On the release date, the senior debt securities will cease to be secured by the collateral bonds and, at our option, either (i) will become our unsecured general obligations or (ii) will be secured by our first mortgage bonds issued under a mortgage indenture other than the current mortgage indenture, which we refer to in this prospectus as “substituted collateral bonds”. The senior indenture provides that, in addition to the senior debt securities offered by this prospectus, other senior debt securities may be issued from time to time, in one or more series, under the senior indenture, without limitation as to aggregate principal amount, provided that, before the release date, the amount of senior debt securities that may be issued cannot exceed the aggregate principal amount of collateral bonds that we are able to issue under the mortgage indenture.

The senior indenture and the mortgage indenture, which we refer to collectively in this prospectus as the “indentures,” do not contain any debt covenants or provisions that would afford holders of the senior debt securities protection in the event of a highly leveraged transaction.

There is no requirement under the indentures that future issues of our debt securities be issued under the indentures. Subject to certain restrictions following the release date, which are described in “Restrictions” below, we will be free to employ other indentures or documentation, containing provisions different from those included in the indentures, in connection with future issues of our debt securities.

Please refer to the prospectus supplement relating to the senior debt securities being offered, which we refer to collectively in this prospectus as the “offered senior debt securities,” for specific terms respecting the offered senior debt securities, including among other terms the following:

The following activities relating to the senior debt securities will occur at the office of the senior trustee in St. Paul, Minnesota:

At the option of the senior trustee, we may pay interest to the registered holder by check or by electronic funds transfer.

The offered senior debt securities will be represented either by global securities registered in the name of a depositary, or its nominee, or by certificates in certificated form issued to the registered holders of the offered senior debt securities as set forth in the applicable prospectus supplement. See “Book Entry Securities” below.

Definitions: For purposes of the descriptions of the senior debt securities, certain defined terms have the following meanings:

“Capitalization” means the total of all the following items appearing on, or included in, our consolidated balance sheet; (i) liabilities for indebtedness maturing more than 12 months from the date of determination; and (ii) common stock, preferred stock, Hybrid Preferred Securities (as defined in the senior indenture), premium on capital stock, capital surplus, capital in excess of par value, and retained earnings (however the foregoing may be designated), less, to the extent not otherwise deducted, the cost of shares of our capital stock held in treasury. Subject to the foregoing, Capitalization shall be determined in accordance with generally accepted accounting principles and practices applicable to the type of business in which we are engaged and that are approved by our regularly retained independent accountants, and may be determined as of a date not more than 60 days before the happening of the event for which the determination is being made.

“Debt” means any outstanding debt for money borrowed evidenced by notes, debentures, bonds or other securities or guarantees of any debt for money borrowed.

“Net Tangible Assets” means the amount shown as total assets on our consolidated balance sheet, less the following: (i) intangible assets including, but without limitation, such items as goodwill, trademarks, trade names, patents, and unamortized debt discount and expense and (ii) appropriate adjustments, if any, on account of minority interests. Net Tangible Assets shall be determined in accordance with generally accepted accounting principles and practices applicable to the type of business in which we are engaged and that are approved by our regularly retained independent accountants, and may be determined as of a date not more than 60 days before the happening of the event for which the determination is being made.

“Operating Property” means (i) any interest in real property that we own and (ii) any asset that we own that is depreciable in accordance with generally accepted accounting principles, excluding, in either case, any of our interests as lessee under any lease (except for a lease that results from a Sale and Lease-Back Transaction) which has been or would be capitalized on the books of the lessee in accordance with generally accepted accounting principles.

“Sale and Lease-Back Transaction” means any arrangement with any person providing for the leasing to us of any Operating Property (except for leases for a term, including any renewals of not more than 48 months), which Operating Property has been or is to be sold or transferred by us to that person; provided, however, Sale and Lease-Back Transaction shall not include any arrangement first entered into before the date of the senior indenture or any transaction in which we sell Operating Property to, and subsequently purchase energy or services from, an entity if the transaction was ordered or authorized by, or was entered into pursuant to any plan or program of industry restructuring ordered or authorized by, any regulatory authority with jurisdiction over us or our operations.

“Value” means, with respect to a Sale and Lease-Back Transaction, as of any particular time, the amount equal to the greater of (i) our net proceeds from the sale or transfer of the property leased pursuant to the Sale and Lease-Back Transaction or (ii) the net book value of the property, as determined by us in accordance with generally accepted accounting principles at the time of entering into the Sale and Lease-Back Transaction, in either case multiplied by a fraction, the numerator of which shall be equal to the number of full years of the term of the lease that is part of the Sale and Lease-Back Transaction remaining at the time of determination and the denominator of which shall be equal to the number of full years of that term, without regard, in any case, to any renewal or extension options contained in the lease.

Original Issue Discount Securities. We may issue the senior debt securities under the senior indenture as original issue discount securities to be offered and sold at a substantial discount below their principal amount. If we do, we will describe the special federal income tax, accounting and other considerations applicable to any original issue discount securities in the prospectus supplement relating to those securities. Original issue discount securities are any securities that provide that an amount less than their principal amount will be due and payable upon a declaration of acceleration of their maturity as a result of the occurrence and continuation of an event of default.

Security; Release Date. Until the release date, one or more series of the collateral bonds that we issue and deliver to the senior trustee will secure the senior debt securities. See “Description of the First Mortgage Bonds.” Upon the issuance of senior debt securities before the release date, we will simultaneously issue and deliver collateral bonds to the senior trustee, as security for those senior debt securities. The collateral bonds will have the same stated rate or rates of interest (or interest calculated in the same manner), interest payment dates, stated maturity date and redemption provisions, and will be in the same aggregate principal amount as the senior debt securities being issued. We have agreed to issue a related series of collateral bonds in the name of the senior trustee in its capacity as trustee under the senior indenture at the same time that we issue each series of senior debt securities. The senior trustee has agreed to hold each series of collateral bonds in that capacity under all circumstances and not transfer the collateral bonds until the earlier of the release date or the retirement of the related series of senior debt securities through redemption, repurchase or otherwise. Before the release date, we will make payments of the principal of, and premium or interest on, each series of collateral bonds to the senior trustee. The senior trustee will apply those payments to satisfaction of all obligations then due on the related series of senior debt securities.

The release date will be the date that all of the first mortgage bonds that are issued and outstanding under our mortgage indenture, other than the collateral bonds, have been retired (at, before or after their maturities) through payment, redemption or otherwise, provided that no default or event of default under the senior indenture has occurred and is continuing. On the release date, the senior trustee will deliver to us for cancellation all collateral bonds and not later than 30 days after the release date will provide notice of the occurrence of the release date to all holders of senior debt securities. As a result, on the release date, the collateral bonds will cease to secure the senior debt securities, and, at our option, the senior debt securities, either (i) will become our unsecured general obligations or (ii) will be secured by substituted collateral bonds. Each issue of collateral bonds will be secured by a lien on certain property that we own. In certain circumstances before the release date, we are permitted to reduce the aggregate principal amount of an issue of collateral bonds held by the senior trustee, but in no event to an amount lower than the aggregate outstanding principal amount of the senior debt securities initially issued contemporaneously with the collateral bonds. Following the release date, we will cause the mortgage indenture to be discharged, and we will not issue any additional bonds under the mortgage indenture.

Restrictions. The senior indenture provides that we may not consolidate with, merge with or into any other corporation (whether or not we are the surviving corporation), or sell, assign, transfer or lease all or substantially all of our properties and assets as an entirety or substantially as an entirety to any person or group of affiliated persons, in one transaction or a series of related transactions, unless: (1) either we will be the continuing person or the person (if other than us) formed by the consolidation or with which or into which we are merged or the

person (or group of affiliated persons) to which we sell, assign, transfer or lease all or substantially all our properties and assets is a corporation (or constitute corporations) and that corporation (A) expressly assumes all our obligations under the senior debt securities and the senior indenture by an indenture supplemental to the senior indenture, executed and delivered to the senior trustee in form satisfactory to the senior trustee and (B) expressly assumes all of our obligations under any outstanding collateral bonds or substituted collateral bonds and under the mortgage indenture or substituted mortgage indenture, by an indenture supplemental to the mortgage indenture (if before the release date) or any substituted mortgage indenture (if on or after the release date), executed and delivered to the mortgage trustee or the trustee under the substituted mortgage indenture in form satisfactory to the mortgage trustee or the trustee under the substituted mortgage indenture; (2) immediately before and after giving effect to the transaction or series of transactions, no event of default, and no default, with respect to the senior debt securities shall have occurred and be continuing; and (3) we shall have delivered to the senior trustee an officer’s certificate and an opinion of counsel, each stating that the consolidation, merger or transfer and the supplemental indentures comply with the senior indenture, the mortgage indenture or the substituted mortgage indenture, as the case may be.

There is inherent uncertainty in the phrase “all or substantially all.” This uncertainty may make it difficult for holders of the senior debt securities to (1) determine whether our covenant relating to consolidation, merger and sale of our properties and assets to another person has been breached, (2) declare an event of default and (3) exercise their acceleration rights. Further, interpretation of this phrase as it relates to any transfer of our properties and assets will be governed by applicable law and will be dependent upon the particular facts and circumstances. In the event the holders of the senior debt securities attempt to exercise their rights under the senior indenture following the occurrence of a particular transfer or series of transfers that they believe constitutes a transfer of “all or substantially all” of our properties and assets and we contest such exercise, we cannot provide any assurance as to how a court would interpret the phrase “all or substantially all.”

Limitation on Liens. The senior indenture provides that, so long as any senior debt securities are outstanding, we may not issue, assume, guarantee or permit to exist after the release date any Debt that is secured by any mortgage, security interest, pledge or lien, which we refer to collectively in this prospectus as liens, of or upon any of our Operating Property, whether owned at the date of the senior indenture or acquired after that date, without in any such case effectively securing the senior debt securities (together with, if we shall so determine, any of our other indebtedness ranking equally with the senior debt securities) equally and ratably with such Debt (but only so long as such Debt is so secured).

In addition, the restriction on liens described in this section will not apply to our issuance, assumption or guarantee of Debt secured by any liens that would otherwise be subject to that restriction up to an aggregate amount which, together with all of our other secured Debt (not including secured Debt permitted under any of the exceptions described above) and the Value of Sale and Lease-Back Transactions existing at that time (other than Sale and Lease-Back Transactions the proceeds of which have been applied to the retirement of certain indebtedness, Sale and Lease-Back Transactions in which the property involved would have been permitted to be subjected to any liens under any of the foregoing exceptions and Sale and Lease-Back Transactions that are permitted by the first sentence of “Limitations on Sale and Lease-Back Transactions” below), does not exceed the greater of 10% of the Net Tangible Assets or 10% of Capitalization.

Limitations on Sale and Lease-Back Transactions. The senior indenture provides that so long as the senior debt securities are outstanding, we may not enter into or permit to exist after the release date any Sale and Lease-Back Transaction with respect to any Operating Property (except for transactions involving leases for a term, including renewals, of not more than 48 months), if the purchaser’s commitment is obtained more than 18 months after the later of the completion of the acquisition, construction or development of the Operating Property or the placing in operation of the Operating Property or of the Operating Property as constructed or developed or substantially repaired, altered or improved. This restriction will not apply if (a) we would be entitled under any of the exceptions described in the second paragraph under “Limitation on Liens” above to issue, assume, guarantee or permit to exist Debt secured by any liens on the Operating Property without equally and ratably securing the senior debt securities, (b) after giving effect to the Sale and Lease-Back Transaction, we could incur pursuant to the provisions described in the third paragraph under “Limitation on Liens,” at least $1.00 of additional Debt secured by liens (other than liens permitted by clause (a)) or (c) we apply within 180 days an amount equal to, in the case of a sale or transfer for cash, the net proceeds (not exceeding the net book value), and, otherwise, an amount equal to the fair value (as determined by our Board of Directors) of the Operating Property so leased to the retirement of our senior debt securities or other Debt ranking senior to or equally with, the senior debt securities, subject to reduction for senior debt securities and such Debt retired during such 180-day period otherwise than pursuant to mandatory sinking fund or prepayment provisions and payments at stated maturity.

Events of Default and Notice of Default. The following events of default under the senior indenture apply to the senior debt securities of any series:

The senior trustee shall, within 30 days after the occurrence of any default or event of default with respect to senior debt securities of any series, give the holders of senior debt securities of that series notice of all uncured defaults or events of default known to it (the term default includes any event which after notice or passage of time or both would be an event of default); provided, however, that, except in the case of an event of default or a default in payment on any senior debt securities of any series, the senior trustee shall be protected in withholding the notice if and so long as the board of directors, the executive committee of the board of directors or responsible officers of the senior trustee in good faith determine that the withholding of the notice is in the interest of the holders of senior debt securities of that series.

If an event of default with respect to senior debt securities of any series (other than due to events of bankruptcy, insolvency or reorganization) occurs and is continuing, the senior trustee or the holders of at least 25% in aggregate principal amount of the outstanding senior debt securities of that series, by notice in writing to us (and to the senior trustee if given by the holders of at least 25% in aggregate principal amount of the senior debt securities of that series) may declare the unpaid principal of and accrued interest to the date of acceleration on all the outstanding senior debt securities of that series to be due and payable immediately and, upon any such declaration, the senior debt securities of that series shall become immediately due and payable.

If an event of default occurs due to bankruptcy, insolvency or reorganization, all unpaid principal of and accrued interest on the outstanding senior debt securities of any series will become immediately due and payable without any declaration or other act on the part of the senior trustee or any holder of any senior debt security of that series. Upon any acceleration of the senior debt securities before the release date, the senior trustee has the power to cause the mandatory redemption of the collateral bonds or substituted collateral bonds, as the case may be.

The holders of not less than a majority of the principal amount of the outstanding senior debt securities of any series may rescind a declaration of acceleration and its consequences with respect to the senior debt securities of that series (including if given, the written demand for redemption of collateral bonds or substituted collateral bonds) if (1) all existing events of default, other than the nonpayment of principal of and interest on the senior debt securities of that series that have become due solely by such declaration of acceleration, have been cured or waived; (2) to the extent lawful, interest on overdue interest and on overdue principal that has become due otherwise than by reason of such acceleration has been paid; (3) the rescission would not conflict with any judgment or decree of a court of competent jurisdiction; and (4) all amounts due to the senior trustee under the senior indenture have been paid. The senior indenture requires us to file periodic statements with the senior

trustee regarding our compliance with certain of the covenants of the senior indenture and to specify any event of default or defaults with respect to senior debt securities, in performing such covenants, of which the signers of the statements may have knowledge.

Modification of the Senior Indenture; Waiver. We and the senior trustee without the consent of any holders may modify the senior indenture with respect to certain matters, including (i) to cure any ambiguity, defect or inconsistency or to correct or supplement any provision which may be inconsistent with any other provision of the senior indenture and (ii) to make any change that does not materially adversely affect the interests of any holder of senior debt securities of any series. In addition, we and the senior trustee may modify certain of our rights and obligations and the rights of holders of the senior debt securities with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding senior debt securities of each series affected by the modifications. None of the following modifications, however, will be effective against any holder of any outstanding senior debt securities of any series affected by the modifications without that holder’s consent:

The holders of not less than a majority in aggregate principal amount of the outstanding senior debt securities of any series may, on behalf of the holders of all senior debt securities of that series, waive any event of default or default under the senior indenture with respect to that series, except an event of default in the payment of the principal of, or premium, if any, or any interest on, any senior debt security of that series or in respect of a provision which under the senior indenture cannot be modified or amended without the consent of the holder of each outstanding senior debt security of the affected series.

Defeasance. We may terminate our substantive obligations under the senior debt securities of any series (except for our obligations to pay the principal of (and premium, if any, on) and the interest on the senior debt securities of that series) by (i) depositing with the senior trustee, under the terms of an irrevocable trust agreement, money or U.S. government obligations sufficient to pay all remaining indebtedness on the senior debt securities of that series, (ii) delivering to the senior trustee either an opinion of counsel or a ruling directed to the senior trustee from the Internal Revenue Service to the effect that the holders of the senior debt securities of that series will not recognize income, gain or loss for federal income tax purposes as a result of the deposit and termination of obligations, and (iii) complying with certain other requirements set forth in the senior indenture.

Voting of Collateral Bonds Held by Senior Trustee. The senior trustee, as holder of collateral bonds, will attend any meeting of holders of first mortgage bonds under the mortgage indenture, as to which it receives due

notice, or, at its option, will deliver its proxy in connection with the meeting. Either at the meeting, or otherwise where the consent of holders of first mortgage bonds is sought without a meeting, the senior trustee will vote or consent with respect to all of the collateral bonds held by it, as directed by the holders of a majority in aggregate principal amount of the outstanding senior debt securities; provided, however, that the senior trustee shall not vote the collateral bonds of any particular series in favor of, or consent to, any action which in the senior trustee’s opinion would materially adversely affect that series of collateral bonds in a manner not shared generally by all other collateral bonds, except upon notification by the senior trustee to the holders of the related series of senior debt securities of the proposal and the receipt of the consent to the proposal of the holders of not less than a majority in principal amount of the outstanding senior debt securities of that series.

Concerning the Senior Trustee. U.S. Bank National Association (“U.S. Bank”), is the senior trustee under the senior indenture. U.S. Bank is also the mortgage trustee under the mortgage indenture and a depositary of our funds. See “Description of the First Mortgage Bonds — Concerning the Mortgage Trustee.” U.S. Bank and its affiliates also provide other banking or investment banking and other financial services to us and our affiliates. The Trust Indenture Act of 1939, as amended, contains limitations on the rights of U.S. Bank, should it become one of our creditors, to obtain payment of claims in certain cases or to realize on certain property received by it in respect of any such claim, as security or otherwise. Under the Trust Indenture Act, U.S. Bank is permitted to engage in other transactions with us and our affiliates from time to time, provided that if U.S. Bank acquires any conflicting interests it must eliminate such conflicts upon the occurrence of an event of default under the senior indenture, or else resign.

Book-Entry Securities. We may initially issue the senior debt securities of any series in the form of one or more global securities under a book-entry only system operated by a securities depository. Unless otherwise specified in the applicable prospectus supplement, The Depository Trust Company (“DTC”), New York, New York, will act as securities depository for each series of senior debt securities. We will issue the senior debt securities as fully-registered securities registered in the name of Cede & Co., DTC’s partnership nominee, or such other name as an authorized representative of DTC may request. We will issue one fully-registered debt security certificate for each issue of the senior debt securities, each in the aggregate principal amount of such issue, and deposit the certificate with DTC.

DTC is a limited-purpose trust company organized under the New York Banking Law, a “banking organization” within the meaning of the New York Banking Law, a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code, and a “clearing agency” registered pursuant to the provisions of Section 17A of the Securities Exchange Act of 1934. DTC also facilitates the post-trade settlement among DTC participants of sales and other securities transactions in deposited securities, through electronic computerized book-entry transfers and pledges between direct participants’ accounts. This eliminates the need for physical movement of securities certificates. Direct participants include both U.S. and non-U.S. securities brokers and dealers, banks, trust companies, clearing corporations, and certain other organizations. DTC is a wholly-owned subsidiary of The Depository Trust & Clearing Corporation (“DTCC”). DTCC is the holding company for DTC, National Securities Clearing Corporation and Fixed Income Clearing Corporation, all of which are registered clearing agencies. DTCC is owned by the users of its regulated subsidiaries. Access to the DTC system is also available to others such as U.S. and non-U.S. securities brokers and dealers, banks, trust companies, and clearing corporations that clear through or maintain a custodial relationship with a direct participant, either directly or indirectly. The DTC rules applicable to its participants are on file with the Securities and Exchange Commission. More information about DTC can be found at www.dtcc.com.

Purchases of debt securities under the DTC system must be made by or through direct participants, which will receive a credit for the debt securities on DTC’s records. The ownership interest of each actual purchaser of each debt security, the beneficial owner, is in turn to be recorded on the records of direct and indirect participants. Beneficial owners will not receive written confirmation from DTC of their purchase. Beneficial owners should, however, receive written confirmations providing details of the transaction, as well as periodic

statements of their holdings, from the direct or indirect participant through which they entered into the transaction. Transfers of ownership interests in the debt securities are accomplished by entries made on the books of direct and indirect participants acting on behalf of beneficial owners. Beneficial owners will not receive certificates representing their ownership interests in debt securities, except in the event that use of the book-entry system for the debt securities is discontinued.

To facilitate subsequent transfers, all debt securities deposited by direct participants with DTC are registered in the name of DTC’s partnership nominee, Cede & Co., or such other name as an authorized representative of DTC may request. The deposit of debt securities with DTC and their registration in the name of Cede & Co. or such other DTC nominee do not effect any change in beneficial ownership. DTC has no knowledge of the actual beneficial owners of the debt securities; DTC’s records reflect only the identity of the direct participants to whose accounts such debt securities are credited, which may or may not be the beneficial owners. The direct and indirect participants will remain responsible for keeping account of their holdings on behalf of their customers.

Conveyance of notices and other communications by DTC to direct participants, by direct participants to indirect participants, and by direct participants and indirect participants to beneficial owners will be governed by arrangements among them, subject to any statutory or regulatory requirements as may be in effect from time to time.

Redemption notices shall be sent to DTC. If less than all of the debt securities within an issue are being redeemed, DTC’s practice is to determine by lot the amount of the interest of each Direct Participant in such issue to be redeemed.

Neither DTC nor Cede & Co. (nor any other DTC nominee) will consent or vote with respect to debt securities unless authorized by the direct participants. Under its usual procedures, DTC mails an omnibus proxy to us as soon as possible after the record date. The omnibus proxy assigns Cede & Co.’s consenting or voting rights to those direct participants to whose accounts debt securities are credited on the record date (identified in a listing attached to the omnibus proxy).

Redemption proceeds, principal payments and interest, premium or other payments on the debt securities will be made to Cede & Co., as DTC’s nominee, or to such other nominee as an authorized representative of DTC may request. DTC’s practice is to credit direct participants’ accounts upon DTC’s receipt of funds and corresponding detail information from us or our paying agent, if any, in accordance with their respective holdings shown on DTC’s records. Payments by participants to beneficial owners will be governed by standing instructions and customary practices, as is the case with securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of such participant and not of DTC, the senior trustee, or us, subject to any statutory or regulatory requirements as may be in effect from time to time. Payment of redemption proceeds, principal payments and interest, premium or other payments to Cede & Co. (or such other nominee as an authorized representative of DTC may request) is the responsibility of us or our paying agent, if any, disbursement of such payments to direct participants will be the responsibility of DTC, and disbursement of such payments to the beneficial owners will be the responsibility of direct and indirect participants.

DTC may discontinue providing its services as depository with respect to the senior debt securities at any time by giving reasonable notice to us or the senior trustee. Under such circumstances, in the event that a successor depository is not obtained, senior debt security certificates are required to be printed and delivered.

We may decide to discontinue use of the system of book-entry-only transfers through DTC (or a successor securities depository). In that event, senior debt security certificates will be printed and delivered to DTC.

The information in this section concerning DTC and DTC’s book-entry system has been obtained from sources that we believe to be reliable, but neither we nor the trustees nor any underwriter takes any responsibility for the accuracy of the information.

Neither we nor the trustees under the indentures will have any responsibility or obligation to any DTC direct or indirect participant or any beneficial owner of a book-entry interest or any other person not shown on the registration books of the trustees as being a holder of the debt securities with respect to: (1) any senior debt securities; (2) the accuracy of any records maintained by DTC or any DTC direct or indirect participant; (3) the payment by DTC or any DTC direct or indirect participant of any amount due to any beneficial owner of a book-entry interest in respect of the principal or redemption price of or interest on the debt securities; (4) the delivery by DTC or any DTC direct or indirect participant of any notice to any beneficial owner of a book-entry interest which is required or permitted under the terms of the indentures to be given to holders of the senior debt securities; (5) the selection of the owners of a book-entry interest to receive payment in the event of any partial redemption of any senior debt securities; or (6) any consent given or other action taken by DTC or its nominee as holder of the senior debt securities.

The following is a summary of the material provisions of the first mortgage bonds and the mortgage indenture. This summary does not purport to be complete and is qualified in its entirety by reference to the more detailed provisions of the mortgage indenture and supplemental indentures, which are incorporated by reference in this prospectus.

General. Before the release date, we will issue to the senior trustee any series of first mortgage bonds issued as collateral bonds. Each issue of collateral bonds to the senior trustee will be in a principal amount equal to the principal amount of the senior debt securities issued contemporaneously with the collateral bonds. Before the release date, we will make payments of the principal of, and premium or interest on, each series of collateral bonds to the senior trustee. The senior trustee will apply those payments to the satisfaction of all obligations then due on the related series of senior debt securities.

Liens and Titles. The collateral bonds will be secured by the mortgage indenture equally and ratably with all other bonds issued under the mortgage indenture (except as to any sinking fund or similar fund established for the benefit of bonds of a particular series). At the time of issuance of each series of the collateral bonds, our counsel will deliver its opinion that the mortgage indenture constitutes, except as stated in this paragraph, a valid and direct first lien upon substantially all of the real and fixed property and governmental licenses and permits that we own (including our interests as tenant-in-common), subject only to permissible encumbrances and to the other limitations and exceptions respecting title to real and fixed properties that are stated in their opinion on title described below. Excepted from the lien are investments in other companies, items of the general character such as would be included on our balance sheet as current assets (unless deposited or required to be deposited with the mortgage trustee), motor vehicles, and timber and minor parcels of real estate. The term “permissible encumbrances” includes liens upon transmission or distribution line rights-of-way, and certain tax and other liens, easements or leases, and other adverse interests of a nature or of a proportion that would not under ordinary circumstances materially impair the lien of the mortgage indenture or the use of the property.

The mortgage indenture by its terms also covers in general all of our after-acquired property, other than property of the nature excepted from the lien of the mortgage indenture as stated above. The lien on an after-acquired system may be subject to a prior lien and, in case of merger, to possible limitation to our system at that time.

At the time of issuance of each series of the collateral bonds, our counsel will deliver its opinion that we have good and marketable title to the real and fixed properties described in the mortgage indenture (other than properties disposed of and released under the mortgage indenture and lands described as held only under flowage rights) free and clear of all liens, charges and encumbrances prior to or on a parity with the lien of the mortgage indenture, except for and subject only to “permissible encumbrances” and to those exceptions, defects and qualifications which in our counsel’s opinion do not materially affect the security for the collateral bonds or title to or our right to use the properties in the conduct of our business. The opinion of counsel does not cover the validity of or title to easements or rights-of-way for transmission and distribution lines.

The mortgage indenture does not prevent us from merging or consolidating with another entity, selling all or substantially all of our assets, or engaging in a recapitalization or other comparable transaction as long as (1) the lien of the mortgage indenture and the rights and powers of the mortgage trustee and the bondholders under the mortgage indenture are not impaired; (2) the principal amount of prior lien bonds secured by a prior lien or liens on property of the successor corporation (exclusive of the property that we owned immediately before the merger, consolidation or sale) and outstanding immediately after the consolidation, merger or sale shall not exceed 60% of the cost or fair value, whichever is less, of the property of the character of permanent additions owned by the successor corporation, immediately before such transaction; (3) the earnings applicable to bond interest of the successor corporation determined as provided in the mortgage indenture, excluding our net earnings, for a period of 12 consecutive calendar months within the 15 consecutive calendar months immediately preceding the first day of the calendar month in which the consolidation, merger or sale is made shall have been in the aggregate at least equal to twice the interest requirements for a period of one year upon all prior lien bonds secured by a prior lien or prior liens on the property of the successor corporation and outstanding immediately after the transaction; and (4) the successor corporation assumes our obligations under the mortgage indenture. If these conditions are satisfied with respect to any such transaction, we may enter into the transaction. Although the mortgage indenture limits the principal amount of additional bonds which we may issue, it does not restrict the amount of unsecured debt that we may incur. Except as described above, the mortgage indenture does not provide any protection to the bondholder against a highly leveraged transaction however structured.

Outstanding and Additional Bonds: Under the mortgage indenture, there were outstanding as of December 31, 2012, $872,100,000 principal amount of bonds of various prior series, $22,000,000 of which matured and was repaid in February 2013. Additional bonds without limit as to aggregate amount may be issued in a principal amount up to (a) 60% of the lesser of cost or fair value of net permanent additions (electric, gas or steam property acquired after January 1, 1941, less retirements after that date taken at undepreciated cost, subject to certain adjustments) except permanent additions otherwise utilized under the mortgage indenture or restricted under the terms of certain supplemental indentures; (b) the amount of bonds retired or cancelled, except from certain funds; and (c) the amount of cash deposited with the mortgage trustee for the purpose, which cash may thereafter be withdrawn in lieu of the issuance of an equal amount of bonds under clauses (a) or (b) but without any earnings’ test requirement. Bonds may be issued under clauses (a) and (c), and under certain circumstances under clause (b), only if earnings applicable to bond interest for a period of 12 months within the preceding 15 months have been at least twice the annual interest requirements upon all bonds then applied for and outstanding.

Earnings applicable to bond interest, as defined in the mortgage indenture, for the year ended December 31, 2012, were $239.8 million, resulting in a ratio of 5.59 times the full annual interest requirements upon all bonds then outstanding, and a ratio of 3.63 after the issuance of $500,000,000 principal amount of collateral bonds at an estimated weighted average interest rate of 4.625% per annum (without taking into account the maturing of $22,000,000 of collateral bonds in February 2013 and $125,000,000 of collateral bonds in December 2013). A difference of 1/8% in the assumed weighted average interest rate on the collateral bonds would change the ratio by approximately 0.034.

The aggregate amount of unbonded bondable property was approximately $689 million as of December 31, 2012, a portion or all of which will be applied as the basis for the issuance of the collateral bonds. The retirement of bonds of prior series may also be the basis for the issuance of additional collateral bonds.

Release Provisions: The mortgage trustee may release property which we have sold from the lien of the mortgage indenture upon our deposit of the fair value of the property with the mortgage trustee. Purchase money obligations so deposited may not exceed 60% of fair value of the released property. We may withdraw release funds on the basis of the lesser of cost or fair value of net permanent additions applied for the purpose, or the principal amount of bonds that we have surrendered, or we may apply release funds to bond retirement. Bonds may be redeemed from release funds only when they are subject to redemption and upon payment of the applicable regular redemption premium. The mortgage trustee may release property certified as no longer necessary in our business and of less than $500,000 value (but not to exceed in the aggregate per year an amount

equal to 1% of the outstanding bonds) upon our covenant to deposit the proceeds of sale, if any, and we may withdraw such proceeds upon our covenant to expend the same for permanent additions.

Modification of Mortgage Indenture: With our consent and the consent of the holders of 70% in principal amount of bonds then outstanding, we and the mortgage trustee may modify the mortgage indenture and the bonds (including the collateral bonds) except as to (a) the due dates, amounts and other terms (other than sinking fund provisions) of payment of principal or interest, or (b) the creation of any lien ranking prior to or on a parity with the lien of the mortgage indenture, or (c) deprivation of any nonassenting bondholder of a lien on the mortgaged property for the security of such bondholder’s bonds, or (d) reduction of the percentage in the amount of bonds required to consent to a modification of the mortgage indenture. We and the mortgage trustee may also modify the mortgage indenture, without any action on the part of the bondholders, provided that any modification that would adversely affect the rights of the holders of any bonds then outstanding may not become effective until all bonds outstanding at the time of the adoption of the modification have been redeemed or retired.

Concerning the Mortgage Trustee: The mortgage trustee under the mortgage indenture is U.S. Bank National Association, which is also the senior trustee under the senior indenture and a depositary of our funds. U.S. Bank and its affiliates also provide other banking or investment banking and other financial services to us and our affiliates. The Trust Indenture Act of 1939 contains limitations on the rights of U.S. Bank, should it become one of our creditors, to obtain payment of claims in certain cases or to realize on certain property received by it in respect of any such claim, as security or otherwise. Under the Trust Indenture Act, U.S. Bank is permitted to engage in other transactions with us and our affiliates from time to time, provided that if U.S. Bank acquires any conflicting interests it must eliminate such conflicts upon the occurrence of an event of default under the mortgage indenture, or else resign.

Defaults and Notice Thereof: The following events are defined as “completed defaults” under the mortgage indenture: (a) default in the payment of the principal of any bond; (b) default continued for 90 days in the payment of any interest upon any bond; (c) default in our covenants with respect to bankruptcy, insolvency, assignment or receivership; or (d) default continued for 90 days after notice to us from the mortgage trustee in the performance of any other covenant, agreement or condition contained in the mortgage indenture. The mortgage trustee may withhold notice to bondholders of defaults (other than in payment of principal, interest or a sinking fund installment) if its responsible officers believe that the withholding of such notice is in the interest of the bondholders.

The holders of a majority in principal amount of the bonds outstanding may direct the mortgage trustee in the exercise of its powers and in the case of a completed default may require the mortgage trustee to declare the maturity of the bonds accelerated, and upon certain conditions may rescind and annul such declaration. The mortgage trustee may decline to follow any direction as to the exercise of its powers if the mortgage trustee (i) is advised by counsel that the directed action may not lawfully be taken or (ii) determines in good faith that compliance with the directions would involve the mortgage trustee in personal liability or that it will not be sufficiently indemnified for any expenditures arising from compliance with the directions.

Evidence of Compliance with Indenture Provisions: The mortgage indenture does not require us to furnish periodic evidence to the mortgage trustee as to absence of defaults or as to general compliance with the terms of the mortgage indenture; however, each time we request the mortgage trustee to take any action, such as the issuance of additional bonds or the release of cash or property under the mortgage indenture, we are required to deliver to the mortgage trustee certain certificates signed and verified by officers, engineers, accountants or other experts, who in certain cases are required to be independent persons. Under pertinent circumstances these certificates certify as to absence of default, the fair value of property in respect of which the action is requested and our net earnings, and in all cases certificates or opinions are required as to our compliance with conditions precedent to such action.

As required by applicable law, these underwriters or agents will be registered broker-dealers or associated persons of registered broker-dealers acting in that capacity. We will describe the plan of distribution for any particular offering of senior debt securities in the corresponding prospectus supplement, in accordance with applicable law.

The prospectus supplement will set forth the terms of the offering of the senior debt securities, including the following:

The distribution of the senior debt securities may be effected from time to time in one or more transactions at a fixed price or prices, which may be changed, or at market prices prevailing at the time of sale, at prices related to such prevailing market prices or at negotiated prices.

Through Underwriters. If we use underwriters in the sale, the underwriters will acquire the senior debt securities for their own account and may resell them from time to time in one or more transactions, including negotiated transactions. We will enter into an underwriting agreement with the underwriter or underwriters once we have reached an agreement for the sale of the senior debt securities. The underwriters may offer the senior debt securities to the public directly or through underwriting syndicates represented by managing underwriters. Unless otherwise provided in the underwriting agreement, the obligations of the underwriters to purchase securities will be subject to conditions precedent, and the underwriters will be obligated to purchase all the securities of a series if any are purchased.

In connection with the sale of the senior debt securities, underwriters may receive compensation from us or from purchasers of the senior debt securities for whom they may act as agents in the form of discounts, concessions or commissions. Underwriters may sell the senior debt securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they act as agents. Any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time. Underwriters, dealers and agents that participate in the distribution of the senior debt securities may be deemed to be underwriters, and any discounts or commissions that they receive from us and any profit on the resale of the senior debt securities by them may be deemed to be underwriting discounts and commissions, under the Securities Act of 1933.

Through Agents. We may sell securities directly or through agents we may designate from time to time. Unless otherwise indicated in the prospectus supplement, any agent will be acting on a best efforts basis for the period of its appointment.

Directly to Purchasers. We may sell senior debt securities directly to one or more purchasers. Under those circumstances, no underwriters, dealers or agents would be involved. We will describe the terms of any direct sales in the prospectus supplement.

We may enter into agreements with underwriters and agents to indemnify them against civil liabilities arising out of this prospectus and the prospectus supplement, including liabilities under the Securities Act of 1933, or to contribute to payments which the agents or underwriters may be required to make relating to those liabilities.

Underwriters or agents may be customers of, engage in transactions with, or perform services for, us in the ordinary course of business.

Representatives of underwriters that we use may engage in overallotment, stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 of Regulation M under the Securities Exchange Act of 1934. Over-allotment involves sales in excess of the offering size, which create a short position for the underwriters. Stabilizing transactions involve bids to purchase the offered securities in the open market for the purpose of pegging, fixing or maintaining the price of the offered securities. Syndicate covering transactions involve purchases of the offered securities in the open market after the distribution has been completed in order to cover syndicate short positions. Penalty bids permit the managing underwriter to reclaim a selling concession from a syndicate member when the securities originally sold by that syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the offered securities to be higher than it would otherwise be in the absence of such transactions. If the representatives engage in stabilizing transactions, syndicate covering transactions or penalty bids, they may discontinue them at any time.

Each series of senior debt securities will be a new issue of securities with no established trading market. We do not propose to list the senior debt securities on a securities exchange. An underwriter may make a market in the senior debt securities, but will not be obligated to do so and may discontinue any market making at any time without notice. No assurance can be given as to the liquidity of the trading market for any senior debt securities.

Foley & Lardner LLP, 777 East Wisconsin Avenue, Milwaukee, Wisconsin 53202, our counsel, will render opinions as to the validity of the senior debt securities. Counsel for the underwriters or agents will pass upon certain legal matters in connection with the offering or offerings of the senior debt securities for the underwriters or agents.

The consolidated financial statements and the related financial statement schedule, incorporated in this prospectus by reference from Wisconsin Public Service Corporation’s Annual Report on Form 10-K, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report, which is incorporated herein by reference. Such consolidated financial statements and the related financial statement schedule have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.


	Per Note		Total
Public offering price(1)		%	$
Underwriting discount		%	$
Proceeds to us, before expenses		%	$



Deutsche Bank Securities	Mizuho Securities	Scotiabank

Goldman, Sachs & Co.	Mitsubishi UFJ Securities	US Bancorp


The Company			S-3
Description of the Notes			S-3
Summary Financial Information			S-6
Book-Entry Issuance—The Depository Trust Company			S-7
Use of Proceeds			S-7
Underwriting (Conflicts of Interest)			S-8
Legal Matters			S-10


	(Dollars in Millions)
	Year Ended December 31,						Nine Months Ended September 30,
	2010		2011		2012		2012		2013
							(Unaudited)
Statement of Income Data
Operating Revenues	$	1,589.0	$	1,563.1	$	1,499.2	$	1,119.8	$	1,173.1
Operating Income		255.0		235.4		224.2		178.1		189.5
Net Income		135.0		125.9		134.8		109.5		109.8


	(Dollars in Millions)
	Amount		As Adjusted(a)		As Adjusted Percentage
Capitalization at September 30, 2013
Long-Term Debt (excluding current portion of $125.0)	$	724.5	$			%
Long-Term Debt to Parent		6.6		6.6
Preferred Stock (without mandatory redemption provisions)		51.2		51.2		%
Common Stock Equity		1,314.8		1,314.8		%

Total Capitalization	$	2,097.1	$			%

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Summary			1
The Company			4
Use of Proceeds			4
Description of the Senior Debt Securities			4
Description of the First Mortgage Bonds			14
Plan of Distribution			17
Legal Matters			18
Experts			18


	Year Ended December 31,										Nine Months Ended September 30,
	2008		2009		2010		2011		2012		2012		2013
Ratio of earnings to fixed charges(a)		5.2		4.2		4.7		4.8		5.4		5.7		5.9


Underwriter		Principal Amount of Notes
Deutsche Bank Securities Inc.		$
Mizuho Securities USA Inc.
Scotia Capital (USA) Inc.
Goldman, Sachs & Co.
Mitsubishi UFJ Securities (USA), Inc.
U.S. Bancorp Investments, Inc.

Total		$


	Paid by us
Per note		%

Total	$