As filed with the Securities and Exchange Commission on April 30, 2018

Registration No. 333-          

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ALLEGHENY TECHNOLOGIES INCORPORATED

(Exact Name of Registrant as Specified in its Charter)

Delaware	25-1792394
(State or Other Jurisdiction of Incorporation or Organization)	(I.R.S. Employer Identification Number)

1000 Six PPG Place

Pittsburgh, Pennsylvania 15222-5479

412-394-2800

(Address, including Zip Code, and Telephone Number, including Area Code, of Registrant’s Principal Executive Offices)

Elliot S. Davis

Senior Vice President, General Counsel,

Chief Compliance Officer and Corporate Secretary

Allegheny Technologies Incorporated

1000 Six PPG Place

Pittsburgh, Pennsylvania 15222-5479

412-394-2800

(Name, Address, including Zip Code, and Telephone Number, including Area Code, of Agent for Service)

Copies to:

Jeffrey W. Acre

K&L Gates LLP

K&L Gates Center

210 Sixth Avenue

Pittsburgh, Pennsylvania 15222-2613

412-355-6500

412-355-6501 (facsimile)

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement as determined by the Registrant.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☒

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☒	Accelerated filer	☐
Non-accelerated filer	☐  (Do not check if a smaller reporting company)	Smaller reporting company	☐
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

Title of Each Class of Securities to be Registered	Amount to be Registered(1)	Proposed Maximum Offering Price Per Unit(1)	Proposed Maximum Aggregate Offering Price(1)	Amount of Registration Fee(1)
Debt Securities
Preferred Stock, $0.10 par value
Common Stock, $0.10 par value
Warrants
Purchase Contracts(2)
Purchase Units(3)
Depositary Shares(4)

(1) An indeterminate aggregate initial offering price or amount of the securities of each identified class is being registered as may from time to time be offered at indeterminate prices. Separate consideration may or may not be received for securities that are issuable upon exercise, conversion or exchange of other securities or that are issued in units or represented by depositary shares. In accordance with Rules 456(b) and 457(r), the registrant is deferring payment of all of the registration fee.

(2) Each purchase contract will represent obligations to purchase from the registrant, or to sell to the registrant, common stock, preferred stock, debt securities, depositary shares or warrants of the registrant, or debt securities of third parties (including U.S. Treasury securities), an index or indices thereof or any combination thereof.

(3) Each purchase unit will be issued under a unit agreement or indenture and will consist of purchase contracts together with common stock, preferred stock, debt securities, depositary shares or warrants of the registrant, or debt securities of third parties (including U.S. Treasury securities), securing the holders’ obligations to purchase the securities under the purchase contracts, or any of these securities in any combination.

(4) Each depositary share will be issued under a deposit agreement, will represent an interest in a fractional share or multiple shares of preferred stock and will be evidenced by a depositary receipt.

PROSPECTUS

Allegheny Technologies Incorporated

Debt Securities

Preferred Stock

Common Stock

Warrants

Purchase Contracts

Purchase Units

Depositary Shares

We may, from time to time, offer to sell, in one or more series, senior or subordinated debt securities, preferred stock, common stock, warrants, purchase contracts, purchase units or depositary shares, or any combination of these securities. The debt securities, preferred stock, warrants and purchase contracts may be convertible into or exercisable or exchangeable for our common or preferred stock or other securities or debt or equity securities of one or more other entities.

Our common stock is listed on the New York Stock Exchange and trades under the ticker symbol “ATI.” If we decide to seek a listing of any securities offered by this prospectus, we will disclose the exchange or market on which the securities will be listed or where we have made an application for listing in one or more supplements to this prospectus.

This prospectus describes some of the general terms that may apply to these securities. The specific terms of any securities to be offered, and the specific manner in which they may be offered, will be described in one or more supplements to this prospectus. This prospectus may not be used to sell securities unless it is accompanied by a prospectus supplement that contains a description of those securities.

We may offer and sell these securities to or through one or more underwriters, dealers or agents, or directly to other purchasers, on a continuous or delayed basis. If any offering involves underwriters, dealers or agents, arrangements with them will be described in a prospectus supplement relating to that offering.

We urge you to carefully read the information included or incorporated by reference in this prospectus and any prospectus supplement for a discussion of factors you should consider before deciding to invest in any securities offered by this prospectus, including the information under “Risk Factors” on page 2 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this Prospectus is April 30, 2018.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS	i
WHERE YOU CAN FIND MORE INFORMATION	ii
SUMMARY	1
RISK FACTORS	2
FORWARD-LOOKING STATEMENTS	2
CONSOLIDATED RATIOS OF EARNINGS TO FIXED CHARGES	3
USE OF PROCEEDS	3
DESCRIPTION OF DEBT SECURITIES	4
DESCRIPTION OF OTHER SECURITIES	12
DESCRIPTION OF CAPITAL STOCK	13
PLAN OF DISTRIBUTION	17
LEGAL MATTERS	19
EXPERTS	19

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission (the “SEC”), using an automatic shelf registration process. By using a shelf registration statement, we may sell, from time to time, in one or more offerings, any combination of the securities described in this prospectus. This prospectus does not contain all of the information in that registration statement. For further information about our business and the securities that may be offered under this prospectus, you should refer to the registration statement and its exhibits. The exhibits to the registration statement contain the full text of certain contracts and other important documents that we have summarized in this prospectus. Since the summaries in this prospectus may not contain all the information that you may find important in deciding whether to purchase the securities we may offer, you should review the full text of these contracts and documents. These summaries are qualified in all respects by reference to all of the provisions contained in the applicable contract or document. The registration statement and its exhibits can be obtained from the SEC as indicated under the heading “Where You Can Find More Information.”

This prospectus only provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that contains specific information about the terms of those securities. The prospectus supplement may also add, update or change information contained in this prospectus. You should read this prospectus and any applicable prospectus supplement together with the additional information described below under the heading “Where You Can Find More Information.”

You should rely only on the information contained or incorporated by reference in this prospectus and any applicable prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should not assume that the information in this prospectus, any prospectus supplement or any document incorporated herein by reference is accurate as of any date other than the date of the applicable document. Our business, financial condition, results of operations and prospects may have changed since that date.

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WHERE YOU CAN FIND MORE INFORMATION

Available Information

We file reports, proxy statements and other information with the SEC. These reports, proxy statements and other information that we file with the SEC can be read and copied at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 to obtain further information on the operation of the Public Reference Room. The SEC maintains an internet site that contains reports, proxy and information statements and other information regarding issuers that file electronically with the SEC, including us. The SEC’s internet address is http://www.sec.gov. In addition, our common stock is listed on the New York Stock Exchange, and our reports and other information can be inspected at the offices of the New York Stock Exchange, 20 Broad Street, New York, New York 10005. Our Internet website is www.atimetals.com. Information contained on our website is not part of, and should not be construed as being incorporated by reference into, this prospectus.

Incorporation by Reference

The SEC allows us to “incorporate by reference” information that we file with it. This means that we can disclose important information to you by referring you to other documents. Any information we incorporate in this manner is considered part of this prospectus except to the extent updated and superseded by information contained in this prospectus. Some information that we file with the SEC after the date of this prospectus and until we sell all of the securities covered by this prospectus will automatically update and supersede the information contained in this prospectus.

We incorporate by reference the following documents that we have filed with the SEC and any filings that we make with the SEC in the future under Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), until we sell all of the securities covered by this prospectus, including between the date of this prospectus and the date on which the offering of the securities under this prospectus is terminated, except as noted in the paragraph below:

Our SEC Filings (File No. 1-12001)	Period for or Date of Filing
Annual Report on Form 10-K	Year Ended December 31, 2017
Current Reports on Form 8-K	February 26, 2018
Registration Statement on Form 8-A	July 30, 1996

Pursuant to General Instruction B of Form 8-K, any information submitted under Item 2.02, Results of Operations and Financial Condition, or Item 7.01, Regulation FD Disclosure, of Form 8-K is not deemed to be “filed” for the purpose of Section 18 of the Exchange Act, and we are not subject to the liabilities of Section 18 with respect to information submitted under Item 2.02 or Item 7.01 of Form 8-K. We are not incorporating by reference any information submitted under Item 2.02 or Item 7.01 of Form 8-K into any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act or into this prospectus.

Statements contained in prospectus as to the contents of any contract, agreement or other document referred to in this prospectus do not purport to be complete, and where reference is made to the particular provisions of that contract, agreement or other document, those references are qualified in all respects by reference to all of the provisions contained in that contract or other document. For a more complete understanding and description of each such contract, agreement or other document, we urge you to read the documents filed as exhibits to the registration statement of which the accompanying prospectus is a part.

Any statement contained in a document incorporated by reference, or deemed to be incorporated by reference, into this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained herein, therein or in any other subsequently filed document which also is incorporated by reference in this prospectus modifies or supersedes that statement. Any such statement so

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modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

We will provide without charge, upon written or oral request, a copy of any or all of the documents that are incorporated by reference into this prospectus and a copy of any or all other contracts, agreements or documents which are referred to in this prospectus. Requests should be directed to: Allegheny Technologies Incorporated, 1000 Six PPG Place, Pittsburgh, PA 15222-5479, Attention: Corporate Secretary; telephone number: (412) 394-2800. You also may review a copy of the registration statement and its exhibits at the SEC’s Public Reference Room in Washington, D.C., as well as through the SEC’s internet site.

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SUMMARY

This summary highlights selected information contained elsewhere in this prospectus and the documents incorporated by reference in this prospectus. Because the following is only a summary, it does not contain all of the information that may be important to you. You should carefully read this prospectus, any accompanying prospectus supplement and the documents incorporated by reference in this prospectus and any accompanying prospectus supplement before deciding whether to invest in any of our securities. References to the “Company”, “we”, “our” and “us” and similar terms means Allegheny Technologies Incorporated and its subsidiaries, unless the context otherwise requires.

Allegheny Technologies Incorporated

We are a global manufacturer of technically advanced specialty materials and complex components. We have a strong presence in the aerospace & defense, oil & gas, electrical energy, medical, and automotive markets. We are a market leader in manufacturing differentiated products that require our unique manufacturing and precision machining capabilities as well as our innovative new product development competence. Our capabilities range from alloy development to final production of highly engineered finished components, as well as producing powders for use in next-generation jet engine forgings and 3D-printed aerospace products. Our common stock is quoted on the New York Stock Exchange under the symbol “ATI”.

Our principal executive offices are located at 1000 Six PPG Place, Pittsburgh, PA 15222, and our telephone number is (412) 394-2800.

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RISK FACTORS

Investing in our securities involves risks. Before deciding to purchase any of our securities, you should carefully consider the discussion of risks and uncertainties under the heading “Risk Factors” contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, which is incorporated by reference in this prospectus, and under similar headings in our subsequently filed quarterly reports on Form 10-Q and annual reports on Form 10-K, as well as the other risks and uncertainties described in any applicable prospectus supplement and in the other documents incorporated by reference in this prospectus. See the information under the heading “Where You Can Find More Information” for information on how to obtain copies of documents incorporated by reference in this prospectus. The risks and uncertainties we discuss in the documents incorporated by reference in this prospectus are those we currently believe may materially affect our company. Additional risks and uncertainties not presently known to us or that we currently believe are immaterial also may materially and adversely affect our business, financial condition and results of operations.

FORWARD-LOOKING STATEMENTS

You should carefully review the information contained in or incorporated by reference into this prospectus. In this prospectus, statements that are not reported financial results or other historical information are “forward-looking statements.” Forward-looking statements give current expectations or forecasts of future events and are not guarantees of future performance. They are based on our management’s expectations that involve a number of business risks and uncertainties, any of which could cause actual results to differ materially from those expressed in or implied by the forward-looking statements.

You can identify these forward-looking statements by the fact that they do not relate strictly to historic or current facts. They use words such as “anticipates,” “believes,” “estimates,” “expects,” “would,” “should,” “will,” “will likely result,” “forecast,” “outlook,” “projects,” and similar expressions in connection with any discussion of future operating or financial performance.

We cannot guarantee that any forward-looking statements will be realized, although we believe that we have been prudent in our plans and assumptions. Achievement of future results is subject to risks, uncertainties and assumptions that may prove to be inaccurate. Among others, the factors discussed in the “Risk Factors” section of our Annual Report on Form 10-K for our fiscal year ended December 31, 2017 and any of our subsequently filed Quarterly Reports on Form 10-Q could cause actual results to differ from those in forward-looking statements included in or incorporated by reference into this prospectus or that we otherwise make. Should known or unknown risks or uncertainties materialize, or should underlying assumptions prove to be inaccurate, actual results could vary materially from those anticipated, estimated or projected. You should bear this in mind as you consider any forward-looking statements.

We undertake no obligation to publicly update forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law. You are advised, however, to consider any additional disclosures that we may make on related subjects in future filings with the SEC. You should understand that it is not possible to predict or identify all factors that could cause our actual results to differ. Consequently, you should not consider any list of factors to be a complete set of all potential risks or uncertainties.

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CONSOLIDATED RATIOS OF EARNINGS TO FIXED CHARGES

The following table sets forth the ratio of our earnings to fixed charges for the periods indicated:

	Year Ended December 31,
	2013			2014			2015			2016			2017
Ratio of earnings to fixed charges		—	(1)		—	(1)		—	(1)		—	(1)		—	(1)

(1) For the years ended December 31, 2013, 2014, 2015, 2016 and 2017, fixed charges exceeded earnings by $192.8 million, $7.1 million, $492.1 million, $750.2 million and $101.9 million, respectively.

For purposes of calculating the ratio of earnings to fixed charges, “earnings” represents income (loss) from continuing operations before income tax provision and cumulative effect of change in accounting principle, plus (income) loss recognized on less than fifty percent owned persons, plus fixed charges, less capitalized interest, less noncontrolling interest in the income of subsidiaries with fixed charges. “Fixed Charges” consists of interest expense, the portion of rents deemed to be interest, capitalized interest and amortization of debt expense.

USE OF PROCEEDS

We intend to use the net proceeds from the sale of the securities for general corporate purposes unless otherwise indicated in the applicable prospectus supplement relating to a specific issuance of securities. Our general corporate purposes include, but are not limited to, repayment, redemption or refinancing of debt, capital expenditures, investments in or loans to subsidiaries and joint ventures, funding of possible acquisitions, working capital, contributions to one or more of our pension plans, satisfaction of other obligations and repurchase of our outstanding equity securities. Pending any such use, the net proceeds from the sale of the securities may be invested in short-term, investment grade, interest-bearing instruments. We will include a more detailed description of the use of proceeds of any specific offering under this prospectus in the applicable prospectus supplement relating to that offering.

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DESCRIPTION OF DEBT SECURITIES

The following is a general description of the debt securities that we may offer from time to time under this prospectus. The particular terms of the debt securities offered under this prospectus and the extent, if any, to which the general provisions described below may apply will be described in the applicable prospectus supplement. Although our securities include securities denominated in U.S. dollars, we may choose to issue securities in any other currency, including the euro.

The debt securities will be either senior debt securities or subordinated debt securities. We will issue the senior debt securities under an indenture, dated June 1, 2009, between Allegheny Technologies Incorporated and The Bank of New York Mellon, as trustee (the “Senior Indenture”). The Senior Indenture is an exhibit to the registration statement of which this prospectus is a part. We will issue the subordinated debt securities under a subordinated indenture between us and The Bank of New York Mellon, as trustee (the “Subordinated Indenture”), a form of which is as an exhibit to the registration statement of which this prospectus is a part. The Senior Indenture and the Subordinated Indenture sometimes are collectively referred to in this prospectus as the indentures, and The Bank of New York Mellon, as trustee under the Senior Indenture or the Subordinated Indenture, as the case may be, sometimes is referred to in this prospectus as the trustee.

The following description is only a summary of the material provisions of the indentures. We urge you to read the appropriate indenture, along with any applicable supplement to the appropriate indenture, because they, and not this description, define your rights as holders of the applicable debt securities. See the information under the heading “Where You Can Find More Information” for information on how to obtain a copy of the appropriate indenture and any applicable supplement to that indenture. The following description also is subject to and qualified by reference to the description of the particular terms of the debt securities, the relevant indenture and any applicable supplement to that indenture, as described in the applicable prospectus supplement, including definitions used in the relevant indenture and any applicable supplement to that indenture. The particular terms of the debt securities that we may offer under this prospectus, the relevant indenture and any applicable supplement to that indenture may vary from the terms described below.

General

The senior debt securities will be unsubordinated obligations, will rank equally with all other unsubordinated debt obligations of ours and, unless otherwise indicated in the applicable prospectus supplement, will be unsecured. The subordinated debt securities will be subordinate in right of payment to any senior debt securities. A description of certain additional terms of the subordinated debt securities is provided below under “— Subordinated Debt Securities.” The specific terms of any subordinated debt securities will be provided in the applicable prospectus supplement. For a complete understanding of the provisions pertaining to the subordinated debt securities, you should refer to the form of the Subordinated Indenture which is an exhibit to the registration statement of which this prospectus is a part. Unless we elect or are required to secure the debt securities, the debt securities will be effectively subordinated to any of our existing and future secured debt to the extent of the assets securing that debt.

Our primary sources of funding for our payment obligations under the debt securities will be revenues from our operations and investments and cash distributions from our subsidiaries. Our subsidiaries are separate and distinct legal entities and have no obligation whatsoever to pay any amounts due on debt securities issued by us or to make funds available to us. Our subsidiaries’ ability to pay dividends or make other payments or advances to us will depend upon their operating results and will be subject to applicable laws and contractual restrictions. The Senior Indenture does not, and the Subordinated Indenture will not, restrict our subsidiaries from entering into agreements that prohibit or limit their ability to pay dividends or make other payments or advances to us.

To the extent that we must rely on cash from our subsidiaries to pay amounts due on the debt securities, the debt securities will be effectively subordinated to all of our subsidiaries’ liabilities, including their trade

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payables. This means that our subsidiaries may be required to pay all of their creditors in full before their assets are available to us. Even if we are recognized as a creditor of our subsidiaries, our claims would be effectively subordinated to any security interests in their assets and also could be subordinated to some or all other claims on their assets and earnings.

In addition to the debt securities that we may offer pursuant to this prospectus, we may issue other debt securities in public or private offerings from time to time. These other debt securities may be issued under other indentures or documentation that are not described in this prospectus, and those debt securities may contain provisions materially different from the provisions applicable to one or more issues of debt securities offered pursuant to this prospectus.

Terms

The Senior Indenture does not, and the Subordinated Indenture will not, limit the principal amount of debt, including unsecured debt, or other securities that we or our subsidiaries may issue.

We may issue notes or bonds in traditional paper form, or we may issue a global security. The debt securities of any series may be issued in definitive form or, if provided in the applicable prospectus supplement, may be represented in whole or in part by a global security or securities, registered in the name of a depositary designated by us. Each debt security represented by a global security is referred to in this prospectus as a “book-entry security.”

Debt securities may be issued from time to time pursuant to this prospectus and will be offered on terms determined by market conditions at the time of sale. Debt securities may be issued in one or more series with the same or various maturities and may be sold at par, a premium or an original issue discount. Debt securities sold at an original issue discount may bear no interest or interest at a rate that is below market rates. Unless otherwise provided in the applicable prospectus supplement, debt securities denominated in U.S. dollars will be issued in denominations of $2,000 and integral multiples of $1,000 in excess thereof.

Please refer to the applicable prospectus supplement for the specific terms of the debt securities offered, including the following:

• Designation of an aggregate principal amount, purchase price and denomination;

• Date of maturity;

• If other than U.S. currency, the currency in which the debt securities may be purchased and the currency in which principal, premium, if any, and interest will be paid;

• The interest rate or rates and the method of calculating interest (unless we specify a different method, interest will be calculated based on a 360-day year consisting of 12 30-day months);

• The date or dates from which the interest will accrue, the payment dates on which any premium and interest will be payable or the manner of determination of the payment dates and the record dates for the determination of holders to whom interest is payable;

• The place or places where principal, premium, if any, and interest will be payable;

• Any redemption or sinking fund provisions or other repayment or repurchase obligations;

• Any index used to determine the amount of principal, premium, if any, and interest to be paid with respect to the debt securities;

• The application, if any, of defeasance provisions to the debt securities;

• If other than the entire principal amount, the portion of the debt securities that would be payable upon acceleration of the maturity thereof;

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• Whether the debt securities will be issued in whole or in part in the form of one or more global securities and, in such case, the depositary for the global securities;

• Whether the debt securities may be converted into or exercised or exchanged for our common stock, preferred stock, warrants, other securities, purchase contracts or purchase units and the terms of such conversion, exercise or exchange, if any;

• Any covenants applicable to the debt securities;

• Any events of default applicable to the debt securities;

• Any changes to the events of default described in this prospectus;

• The terms of subordination, if applicable;

• The terms of conversion, if applicable; and

• Any other specific material terms, including any additions to the terms described in this prospectus and any terms that may be required by or advisable under applicable law.

Except with respect to book-entry securities, debt securities may be presented for exchange or registration of transfer, in the manner, at the places and subject to the restrictions set forth in the debt securities and the applicable prospectus supplement. Such services will be provided without charge, other than any tax or other governmental charge payable in connection therewith, but subject to the limitations provided in the indentures.

Merger, Consolidation or Sale of Assets

Pursuant to the indentures, the Company will not, in a single transaction or through a series of related transactions, consolidate or merge with or into any other person, or, directly or indirectly, sell or convey all or substantially all of its properties and assets to another person or group of affiliated persons, except that the Company may consolidate or merge with, or sell or convey substantially all of its assets to another person if (i) the Company is the continuing person or the successor person (if other than the Company) is organized and existing under the laws of the United States of America, any State thereof or the District of Columbia and such person expressly assumes all obligations of the Company under the indenture, including payment of the principal and interest on the debt securities, and the performance and observance of all of the covenants and conditions of the indenture to be performed by the Company and (ii) there is no default under the indenture. Upon such a succession, the Company will be relieved from any further obligations under the indenture.

Events of Default

Except as otherwise set forth in the applicable prospectus supplement, an event of default shall occur with respect to any series of debt securities when:

• We default in paying principal or premium, if any, on any of the debt securities of such series when due;

• We default in paying interest on any of the debt securities of such series when due and such default continues for 30 days;

• We default in making deposits into any sinking fund payment with respect to any of the debt securities of such series when due and such default continues for 30 days;

• We fail to perform any other covenant or warranty in the debt securities of such series or in the applicable indenture, and such failure continues for a period of 90 days after notice of such failure as provided in that indenture;

• Certain events of bankruptcy, insolvency or reorganization involving us occur; or

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• Any other event of default specified in the applicable prospectus supplement occurs with respect to debt securities of that series.

We will be required annually to deliver to the trustee an officers’ certificate stating whether or not the officers signing such certificate have any knowledge of any default in the performance by us of our obligations under the applicable indenture.

If an event of default shall occur and be continuing with respect to any series (other than an event of default described in the fifth bullet point of the first paragraph above under “— Events of Default”), the trustee or the holders of not less than 25% in principal amount of the debt securities of such series then outstanding (or, if any debt securities of that series are original issue discount securities, the portion of the principal amount of such securities as may be specified by the terms thereof) may declare the debt securities of such series to be immediately due and payable. If an event of default described in the fifth bullet point of the first paragraph above under “— Events of Default” occurs with respect to any series of debt securities, the principal amount of all debt securities of that series (or, if any debt securities of that series are original issue discount securities, the portion of the principal amount of such securities as may be specified by the terms thereof) will automatically become due and payable without any declaration by the trustee or the holders. The trustee is required to give holders of the debt securities of any series written notice of a default with respect to such series as and to the extent provided by the Trust Indenture Act of 1939, as amended. As used in this paragraph, a “default” means an event described in the first paragraph above under “— Events of Default” without including any applicable grace period.

If at any time after the debt securities of such series have been declared due and payable, and before any judgment or decree for the moneys due has been obtained or entered, we pay or deposit with the trustee amounts sufficient to pay all matured installments of interest upon the debt securities of such series and the principal of all debt securities of such series which shall have become due, otherwise than by acceleration, together with interest on such principal and, to the extent legally enforceable, on such overdue installments of interest and all other amounts due under the applicable indenture shall have been paid, and any and all defaults with respect to such series under that indenture shall have been remedied, then the holders of a majority in aggregate principal amount of the debt securities of such series then outstanding, by written notice to us and the trustee, may rescind and annul the declaration that the debt securities of such series are due and payable.

In addition, the holders of a majority in aggregate principal amount of the debt securities of such series may waive any past default and its consequences with respect to such series, except a default in the payment of the principal of or any premium or interest on any debt securities of such series or a default in the performance of a covenant that cannot be modified under the applicable indenture without the consent of the holder of each affected debt security.

The trustee is under no obligation to exercise any of the rights or powers under the indentures at the request, order or direction of any of the holders of debt securities, unless such holders shall have offered to the trustee security or indemnity satisfactory to the trustee. Subject to such provisions for the indemnification of the trustee and certain limitations contained in the indentures, the holders of a majority in aggregate principal amount of the debt securities of each series at the time outstanding shall have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of such series.

No holder of debt securities of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the applicable indenture, for the appointment of a receiver or trustee or for any other remedy under the indenture, unless:

• The holder has previously given written notice to the trustee of a continuing event of default with respect to the debt securities of that series; and

• The holders of at least 25% in principal amount of the outstanding debt securities of that series have made a written request to the trustee, and offered reasonable indemnity satisfactory to the trustee, to

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institute proceedings as trustee, the trustee has failed to institute the proceedings within 60 days after its receipt of such notice and the trustee has not received from the holders of a majority in principal amount of the debt securities of that series a direction inconsistent with that request.

Notwithstanding the foregoing, the holder of any debt security issued under indentures will have an absolute and unconditional right to receive payment of the principal of and any premium and, subject to the provisions of the applicable indenture regarding the payment of default interest, interest on that debt security on the due dates expressed in that security and to institute suit for the enforcement of payment.

Modification of the Indentures

The Senior Indenture contains, and the Subordinated Indenture will contain, provisions permitting us and the trustee to modify that indenture or enter into or modify any supplemental indenture without the consent of the holders of the debt securities for any of the following purposes:

• To evidence the succession of another corporation to us in accordance with “— Merger, Consolidation or Sale of Assets”;

• To add to our covenants further covenants for the benefit or protection of the holders of any or all series of debt securities or to surrender any right or power conferred upon us by that indenture;

• To add any additional events of default with respect to all or any series of debt securities;

• To add to or change any of the provisions of that indenture to facilitate the issuance of debt securities in bearer form with or without coupons, or to permit or facilitate the issuance of debt securities in uncertificated form;

• To add to, change or eliminate any of the provisions of that indenture in respect of one or more series of debt securities thereunder, under certain conditions designed to protect the rights of any existing holder of those debt securities;

• To secure all or any series of debt securities;

• To establish the forms or terms of the debt securities of any series;

• To evidence the appointment of a successor trustee and to add to or change provisions of that indenture necessary to provide for or facilitate the administration of the trusts under that indenture by more than one trustee; and

• To cure any ambiguity, to correct or supplement any provision of that indenture which may be defective or inconsistent with another provision of that indenture or to change any other provisions with respect to matters or questions arising under that indenture, provided that any such action shall not adversely affect the interests of the holders of any series of debt securities.

We and the trustee may otherwise modify each indenture or any supplemental indenture with the consent of the holders of not less than a majority in aggregate principal amount of each series of debt securities affected thereby at the time outstanding, except that no such modifications shall:

• Change the fixed maturity of any debt securities or any installment of principal, interest or premium on any debt securities, or reduce the principal amount thereof or reduce the rate of interest or premium payable upon redemption, or reduce the amount of principal of an original issue discount debt security or any other debt security that would be due and payable upon a declaration of acceleration of the maturity thereof, or change the currency in which the debt securities are payable or impair the right to institute suit for the enforcement of any payment after the stated maturity thereof or the redemption date, if applicable, or adversely affect any right of the holder of any debt security to require us to repay or repurchase that security, without the consent of the holder of each debt security so affected;

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• Reduce the percentage of debt securities of any series, the consent of the holders of which is required for any waiver or supplemental indenture, without the consent of the holders of all debt securities affected thereby then outstanding;

• Modify the provisions of that indenture relating to the waiver of past defaults or the waiver or certain covenants or the provisions described above, except to increase any percentage set forth in those provisions or to provide that other provisions of that indenture may not be modified without the consent of the holder of each debt security affected thereby, without the consent of the holder of each debt security affected thereby;

• Change any obligation of ours to maintain an office or agency;

• Change any obligation of ours to pay additional amounts;

• Adversely affect any right of repayment or repurchase at the option of the holder; or

• Reduce or postpone any sinking fund or similar provision.

With respect to any vote of holders of a series of debt securities, we generally will be entitled to set any date as a record date for the purpose of determining the holders of outstanding debt securities that are entitled to vote or take other action under the applicable indenture.

Satisfaction and Discharge, Defeasance and Covenant Defeasance

Except as otherwise specified in the applicable prospectus supplement, each indenture shall be satisfied and discharged if (i) we shall deliver to the trustee all debt securities then outstanding for cancellation or (ii) all debt securities not delivered to the trustee for cancellation shall have become due and payable, are to become due and payable within one year or are to be called for redemption within one year and we shall deposit an amount sufficient to pay the principal, premium, if any, and interest to the date of maturity, redemption or deposit (in the case of debt securities that have become due and payable), provided that in either case we shall have paid all other sums payable under that indenture.

The Senior Indenture provides, and the Subordinated Indenture will provide, if such provision is made applicable to the debt securities of a series, that we may elect either (A) to defease and be discharged from any and all obligations with respect to any debt security of such series, or “defeasance,” or (B) to be released from our obligations with respect to such debt security under certain of the covenants and events of default under that indenture together with additional covenants that may be included for a particular series and that certain events of default shall not be events of default under that indenture with respect to such series (“covenant defeasance”), upon the deposit with the trustee (or other qualifying trustee), in trust for such purpose, of money or certain U.S. government obligations which through the payment of principal and interest in accordance with their terms will provide money, in an amount sufficient to pay the principal of (and premium, if any) and interest on such debt security, on the scheduled due dates.

In the case of defeasance or covenant defeasance, the holders of such debt securities will be entitled to receive payments in respect of such debt securities solely from such trust. Such a trust may only be established if, among other things, we have delivered to the trustee an opinion of counsel (as specified in the indentures) to the effect that the holders of the debt securities affected thereby will not recognize income, gain or loss for Federal income tax purposes as a result of such defeasance or covenant defeasance and will be subject to Federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such defeasance or covenant defeasance had not occurred. Such opinion of counsel, in the case of defeasance under clause (A) above, must refer to and be based upon a ruling of the Internal Revenue Service or a change in applicable Federal income tax law occurring after the date of the applicable indenture.

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Record Dates

The Senior Indenture provides, and the Subordinated Indenture will provide, that in certain circumstances we may establish a record date for determining the holders of outstanding debt securities of a series entitled to join in the giving of notice or the taking of other action under the applicable indenture by the holders of the debt securities of such series.

Subordinated Debt Securities

Subordinated debt securities will be subordinate, in right of payment, to all senior debt. Senior debt means, with respect to us, the principal, premium, if any, interest, fees, charges, expenses, reimbursement obligations, guarantees and other amounts owing on the following:

• All indebtedness of ours, whether outstanding on the date of issuance or thereafter created, incurred or assumed, which is for money borrowed, or evidenced by a note or similar instrument given in connection with the acquisition of any business, properties or assets, including securities;

• Any indebtedness of others of the kinds described in the preceding clause for the payment of which we are responsible or liable (directly or indirectly, contingently or otherwise) as guarantor or otherwise; and

• Amendments, renewals, extensions and refundings of any indebtedness described above, unless in any instrument or instruments evidencing or securing such indebtedness or pursuant to which the same is outstanding, or in any such amendment, renewal, extension or refunding, it provides that such indebtedness is not senior or prior in right of payment to the subordinated debt securities.

Upon any distribution of our assets upon our dissolution, winding up, liquidation or reorganization, the payment of the principal, premium, if any, and interest, if any, on the subordinated debt securities will be subordinated, to the extent provided in the Subordinated Indenture, in right of payment to the prior payment in full of all of our senior debt. Our obligation to make payment of the principal, premium, if any, and interest, if any, on the subordinated debt securities will not otherwise be affected. In addition, no payment on account of principal and premium, if any, sinking fund or interest, if any, may be made on the subordinated debt securities at any time unless full payment of all amounts due in respect of the principal and premium, if any, sinking fund and interest, if any, on our senior debt has been made or duly provided for in money or money’s worth.

Notwithstanding the foregoing, unless all of our senior debt has been paid in full, in the event that any payment or distribution made by us is received by the trustee or the holders of any of the subordinated debt securities, such payment or distribution must be paid over to the holders of our senior debt or a person acting on their behalf, to be applied toward the payment of all of our senior debt remaining unpaid until all the senior debt has been paid in full. Subject to the payment in full of all of our senior debt, the rights of the holders of our subordinated debt securities will be subrogated to the rights of the holders of our senior debt.

By reason of this subordination, in the event of a distribution of our assets upon our insolvency, certain of our general creditors may recover more, ratably, than holders of our subordinated debt securities.

Governing Law

The laws of the State of New York governs the Senior Indenture, will govern the Subordinated Indenture and will govern the debt securities issued under the indentures.

“Street Name” and Other Indirect Holders

Investors who hold securities in accounts at banks or brokers generally will not be recognized by us as legal holders of debt securities. This is called holding in “street name.” Instead, we would recognize only the bank or

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broker, or the financial institution that the bank or broker uses to hold its securities. These intermediary banks, brokers and other financial institutions pass along principal, interest and other payments on the debt securities, either because they agree to do so in their customer agreements or because they are legally required to do so. If you hold debt securities in “street name,” you should check with your own institution to find out, among other things:

• How it handles payments and notices;

• Whether it imposes fees or charges;

• How it would handle voting if applicable;

• Whether and how you can instruct it to send you debt securities registered in your own name so you can be a direct holder as described below; and

• If applicable, how it would pursue rights under your debt securities if there were a default or other event triggering the need for holders to act to protect their interests.

Our obligations, as well as the obligations of the trustee under the indentures and those of any third parties employed by us or the trustee under either of the indentures, run only to persons who are registered as holders of debt securities issued under the applicable indenture. As noted above, we do not have obligations to you if you hold in “street name” or other indirect means, either because you choose to hold debt securities in that manner or because the debt securities are issued in the form of global securities as described below. For example, once we make payment to the registered holder, we have no further responsibility for the payment even if that holder is legally required to pass the payment along to you as a “street name” customer but does not do so.

Book-Entry Securities

The following description of book-entry securities will apply to any series of debt securities issued in whole or in part in the form of one or more global securities except as otherwise described in the applicable prospectus supplement.

Book-entry securities of like tenor and having the same date will be represented by one or more global securities deposited with and registered in the name of a depositary that is a clearing agent registered under the Exchange Act. Beneficial interests in book-entry securities will be limited to institutions that have accounts with the depositary, or “participants,” or persons that may hold interests through participants.

Ownership of beneficial interests by participants will only be evidenced by, and the transfer of that ownership interest will only be effected through, records maintained by the depositary. Ownership of beneficial interests by persons that hold through participants will only be evidenced by, and the transfer of that ownership interest within such participant will only be effected through, records maintained by the participants. The laws of some jurisdictions require that certain purchasers of securities take physical delivery of such securities in definitive form. Such laws may impair the ability to transfer beneficial interests in a global security.

Payment of principal of and any premium and interest on book-entry securities represented by a global security registered in the name of or held by a depositary will be made to the depositary, as the registered owner of the global security. Neither we, the trustee nor any agent of ours or the trustee will have any responsibility or liability for any aspect of the depositary’s records or any participant’s records relating to or payments made on account of beneficial ownership interests in a global security or for maintaining, supervising or reviewing any of the depositary’s records or any participant’s records relating to the beneficial ownership interests. Payments by participants to owners of beneficial interests in a global security held through such participants will be governed by the depositary’s procedures, as is now the case with securities held for the accounts of customers registered in “street name,” and will be the sole responsibility of such participants.

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A global security representing a book-entry security will be exchangeable for definitive debt securities in registered form, of like tenor and of an equal aggregate principal amount registered in the name of, or is transferable in whole or in part to, a person other than the depositary for that global security, only if:

• The depositary notifies us that it is unwilling or unable to continue as depositary for that global security and we do not appoint a successor depositary within 90 days after receiving that notice;

• At any time the depositary ceases to be a clearing agency registered under the Exchange Act and we do not appoint a successor depositary within 90 days after becoming aware that the depositary has ceased to be registered as a clearing agency;

• We in our sole discretion determine that that the global security is so transferable or will be exchangeable for definitive securities in registered form and, in each case, notify the trustee of our decision;

• An event of default with respect to the debt securities of that series has occurred and is continuing; or

• Other circumstances exist that have been specified in the terms of the debt securities of that series.

Any global security that is exchangeable pursuant to the preceding sentence shall be registered in the name or names of such person or persons as the depositary shall instruct the trustee. It is expected that such instructions may be based upon directions received by the depositary from its participants with respect to ownership of beneficial interests in such global security.

Except as provided above, owners of beneficial interests in a global security will not be entitled to receive physical delivery of debt securities in definitive form and will not be considered the holders thereof for any purpose under the indentures, and no global security shall be exchangeable, except for a security registered in the name of the depositary. This means each person owning a beneficial interest in such global security must rely on the procedures of the depositary and, if such person is not a participant, on the procedures of the participant through which such person owns its interest, to exercise any rights of a holder under the indentures. We understand that under existing industry practices, if we request any action of holders or an owner of a beneficial interest in such global security desires to give or take any action that a holder is entitled to give or take under the indentures, the depositary would authorize the participants holding the relevant beneficial interests to give or take such action, and such participants would authorize beneficial owners owning through such participant to give or take such action or would otherwise act upon the instructions of beneficial owners owning through them.

DESCRIPTION OF OTHER SECURITIES

We will set forth in the applicable prospectus supplement a description of any warrants, purchase contracts, purchase units or depositary shares that may be offered pursuant to this prospectus.

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DESCRIPTION OF CAPITAL STOCK

Common Stock

We may issue, either separately or together with other securities, including as a part of purchase units, shares of our common stock. Shares of common stock issued as part of purchase units may be attached to or separate from any other securities part of those purchase units. Under our Restated Certificate of Incorporation, we are authorized to issue up to 500,000,000 shares of our common stock. As of April 20, 2018, we had 125,647,226 shares of common stock issued and outstanding and had reserved approximately 8,149,432 million additional shares of common stock for issuance under our stock compensation plans.

A prospectus supplement relating to an offering of common stock or other securities convertible or exchangeable for, or exercisable into, common stock, or the settlement of which may result in the issuance of common stock, will describe the relevant terms of the offering, including the number of shares offered, any initial offering price and market price and dividend information, as well as, if applicable, information on other related securities.

The following summary is not complete and is not intended to give full effect to provisions of statutory or common law. You should refer to the applicable provisions of the following:

• The Delaware General Corporation Law, as it may be amended from time to time;

• Our Restated Certificate of Incorporation, as it may be amended or further restated from time to time; and

• Our Bylaws, as they may be further amended or restated from time to time.

Dividends. The holders of our common stock are entitled to receive dividends when, as and if declared by our board of directors, out of funds legally available for their payment subject to the rights of holders of our preferred stock.

Voting Rights. The holders of our common stock are entitled to one vote per share on all matters submitted to a vote of stockholders.

Rights upon Liquidation. In the event of our voluntary or involuntary liquidation, dissolution or winding up, the holders of common stock will be entitled to share equally in any of our assets available for distribution after the payment in full of all debts and distributions and after the holders of all series of our outstanding preferred stock have received their liquidation preferences in full.

Miscellaneous. The outstanding shares of common stock are fully paid and nonassessable. The holders of common stock are not entitled to preemptive or redemption rights. Shares of common stock are not convertible into shares of any other class of capital stock. Computershare Shareowner Services LLC is the transfer agent and registrar for the common stock.

Preferred Stock

We may elect to issue shares of our preferred stock from time to time, as described in the applicable prospectus supplement. We may issue shares of preferred stock separately or as a part of purchase units, and any such shares issued as part of purchase units may be attached to or separate from any other securities part of those purchase units. Shares of our preferred stock may have dividend, redemption, voting and liquidation rights taking priority over our common stock, and shares of our preferred stock may be convertible into our common stock.

Our Board of Directors is authorized, subject to any limitations prescribed by law, to provide for the issuance of shares of preferred stock in one or more series. In addition, our Board of Directors is authorized to

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establish from time to time the number of shares to be included in each series of preferred stock and to fix the designation, powers (including but not limited to voting powers, if any), preferences and rights of the shares of each series of preferred stock and any qualifications, limitations or restrictions of each series of preferred stock. The number of authorized shares of preferred stock may be increased or decreased (but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of a majority of the outstanding common stock, without a vote of the holders of the preferred stock, or of any series of preferred stock, unless a vote of any such holders is required pursuant to the terms of any preferred stock.

Our Restated Certificate of Incorporation authorizes our Board of Directors without further stockholder action, to provide for the issuance of up to 50,000,000 shares of preferred stock, in one or more series. As of the date of this prospectus, no shares of preferred stock have been issued, and 50,000,000 shares of preferred stock are available for issuance. We have 6,000,000 shares of preferred stock designated as Series A Junior Participating Preferred Stock in connection with our prior rights agreement, leaving 44,000,000 shares of preferred stock remaining available for designation as of the date of this prospectus.

The particular terms of any series of preferred stock being offered by us under this prospectus will be described in the prospectus supplement relating to that series of preferred stock. Those terms may include:

• The title and liquidation preference per share of the preferred stock;

• The number of shares offered;

• The purchase price of the preferred stock;

• The dividend rate (or method of calculation), the dates on which dividends will be paid and the date from which dividends will begin to accumulate;

• Any redemption or sinking fund provisions of the preferred stock;

• Any conversion provisions of the preferred stock;

• The voting rights, if any, of the preferred stock; and

• Any additional dividend, liquidation, redemption, sinking fund and other rights, preferences, privileges, limitations and restrictions of the preferred stock.

If the terms of any series of preferred stock being offered differ from the terms set forth in this prospectus, the definitive terms will be disclosed in the applicable prospectus supplement. The summary in this prospectus is not complete. You should refer to the applicable Certificate of Amendment to our Restated Certificate of Incorporation or certificate of designations, as the case may be, establishing a particular series of preferred stock, in either case which will be filed with the Secretary of State of the State of Delaware and the SEC in connection with an offering of preferred stock.

The preferred stock will, when issued, be fully paid and nonassessable.

Dividend Rights. The preferred stock will be preferred over our common stock as to payment of dividends. Before any dividends or distributions (other than dividends or distributions payable in common stock) on our common stock will be declared and set apart for payment or paid, the holders of shares of each series of preferred stock will be entitled to receive dividends when, as and if declared by our board of directors. We will pay those dividends either in cash, shares of common stock or preferred stock or otherwise, at the rate and on the date or dates set forth in the applicable prospectus supplement. With respect to each series of preferred stock, the dividends on each share of the series will be cumulative from the date of issue of the share unless another date is set forth in the applicable prospectus supplement relating to the series. Accruals of dividends will not bear interest.

Rights upon Liquidation. The preferred stock will be preferred over our common stock as to assets so that the holders of each series of preferred stock will be entitled to be paid, upon our voluntary or involuntary

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liquidation, dissolution or winding up and before any distribution is made to the holders of common stock, the amount set forth in the applicable prospectus supplement. However, in this case the holders of preferred stock will not be entitled to any other or further payment. If upon any liquidation, dissolution or winding up our net assets are insufficient to permit the payment in full of the respective amounts to which the holders of all outstanding preferred stock are entitled, our entire remaining net assets will be distributed among the holders of each series of preferred stock in amounts proportional to the full amounts to which the holders of each series are entitled.

Redemption. All shares of any series of preferred stock will be redeemable to the extent set forth in the prospectus supplement relating to the series. All shares of any series of preferred stock will be convertible into shares of our common stock or into shares of any other series of our preferred stock to the extent set forth in the applicable prospectus supplement.

Voting Rights. Except as indicated in the applicable prospectus supplement, the holders of preferred stock will be entitled to one vote for each share of preferred stock held by them on all matters properly presented to stockholders. The holders of common stock and the holders of all series of preferred stock will vote together as one class.

Additional Series of Preferred Stock. In the event of a proposed merger or tender offer, proxy contest or other attempt to gain control of us and not approved by our board of directors, it would be possible for the board to authorize the issuance of one or more series of preferred stock with voting rights or other rights and preferences which would impede the success of the proposed merger, tender offer, proxy contest or other attempt to gain control of us. This authority may be limited by applicable law, our Restated Certificate of Incorporation, as it may amended or further restated from time to time, and the applicable rules of the stock exchanges upon which the common stock is listed. The consent of our stockholders would not be required for any such issuance of preferred stock.

Special Charter Provisions. Our Restated Certificate of Incorporation provides that:

• Our Board of Directors is classified into three classes;

• In addition to the requirements of law and the other provisions of our Restated Certificate of Incorporation, the affirmative vote of at least two-thirds of the outstanding shares of our common stock is required for the adoption or authorization of any of the following events unless the event has been approved at a meeting of our Board of Directors by the vote of more than two-thirds of the incumbent members of our Board of Directors:

• Any merger or consolidation of us with or into any other corporation;

• Any sale, lease, exchange, transfer or other disposition, but excluding a mortgage or any other security device, of all or substantially all of our assets;

• Any merger or consolidation of a Significant Shareholder (as defined in our Restated Certificate of Incorporation) with or into us or a direct or indirect subsidiary of ours;

• Any sale, lease, exchange, transfer or other disposition to us or to a direct or indirect subsidiary of ours of any of our common stock held by a Significant Shareholder or any other assets of a Significant Shareholder which, if included with all other dispositions consummated during the same fiscal year of ours by the same Significant Shareholder, would result in dispositions of assets having an aggregate fair value in excess of five percent of our total consolidated assets as shown on our certified balance sheet as of the end of the fiscal year preceding the proposed disposition;

• Any reclassification of our common stock, or any re-capitalization involving our common stock, consummated within five years after a Significant Shareholder becomes a Significant Shareholder, whereby the number of outstanding shares of common stock is reduced or any of those shares are converted into or exchanged for cash or other securities;

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• Any dissolution; and

• Any agreement, contract or other arrangement providing for any of these transactions but notwithstanding anything not including any merger pursuant to the Delaware General Corporation Law, as amended from time to time, which does not require a vote of our stockholders for approval;

• Our stockholders may not alter, amend, supplement or repeal, or adopt any provision inconsistent with the purpose or intent of, certain provisions contained in our Restated Certificate of Incorporation other than by the affirmative vote of 75% of the combined voting power of all of our outstanding voting securities entitled to vote generally in an election of directors, voting together as a single class;

• Our stockholders may not adopt, amend or repeal our Amended and Restated Bylaws other than by the affirmative vote of 75% of the combined voting power of all of our outstanding voting securities entitled to vote generally in an election of directors, voting together as a single class;

• Any action required or permitted to be taken by our stockholders must be effected at a duly called annual or special meeting of stockholders and may not be effected by the written consent of the stockholders; and

• Special meetings of the stockholders may be called at any time by a majority of our directors and may not be called by any other person or persons or in any other manner.

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PLAN OF DISTRIBUTION

We may sell the securities in one or more of the following ways:

• To underwriters, whether or not part of a syndicate, for public offering and sale by them;

• Directly to purchasers in negotiated sales or in competitively bid transactions;

• Through agents;

• Through dealers; or

• Through a combination of any of the above methods of sale.

Offers to purchase securities may be solicited directly by us or by agents designated by us from time to time. Any agent, who may be deemed to be an underwriter, as that term is defined in the Securities Act, involved in the offer and sale of the securities will be named, and any commissions payable by us to that agent will be provided, in an applicable prospectus supplement. We and our agents may sell the securities at:

• A fixed price or prices, which may be changed;

• Market prices prevailing at the time of sale;

• Prices related to such prevailing market prices; or

• Negotiated prices.

Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions under the Securities Act. Underwriters, dealers and agents may be entitled, under agreements with us, to indemnification against and contribution toward certain civil liabilities, including liabilities under the Securities Act, and to reimbursement by us for certain expenses. Unless otherwise described in an applicable prospectus supplement, the obligations of the underwriters to purchase offered securities will be subject to conditions, and the underwriters must purchase all of the offered securities if any are purchased.

If an underwriter or underwriters are used in the offer or sale of securities, we will execute an underwriting agreement with the underwriters at the time of sale of the securities to the underwriters, and the names of the underwriters and the principal terms of our agreements with the underwriters will be provided in an applicable prospectus supplement.

The securities subject to the underwriting agreement may be acquired by the underwriters for their own account and may be resold by them from time to time in one or more transactions, including negotiated transactions, at a fixed offering price or at varying prices determined at the time of sale. Underwriters may be deemed to have received compensation from us in the form of underwriting discounts or commissions and may also receive commissions from the purchasers of these securities for whom they may act as agent. Underwriters may sell these securities to or through dealers. These dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and commissions from the purchasers for whom they may act as agent. Any initial offering price and any discounts or concessions allowed or re-allowed or paid to dealers may be changed from time to time.

In connection with underwritten offerings of the securities, the underwriters may engage in over-allotment, stabilizing transactions, covering transactions and penalty bids in accordance with Regulation M under the Exchange Act, as follows:

• Over-allotment transactions that involve sales in excess of the offering size, which create a short position for the underwriters;

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• Stabilizing transactions that permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum;

• Covering transactions that involve purchases of the securities in the open market after the distribution has been completed in order to cover short positions; and

• Penalty bids that permit the underwriters to reclaim a selling concession from a broker/dealer when the securities originally sold by that broker-dealer are repurchased in a covering transaction to cover short positions.

These stabilizing transactions, covering transactions and penalty bids may cause the price of the securities to be higher than it otherwise would be in the absence of these transactions. If these transactions occur, they may be discontinued at any time.

If indicated in an applicable prospectus supplement, we will authorize dealers acting as agents for us to solicit offers by certain institutions to purchase securities from us at the public offering price set forth in the prospectus supplement under delayed delivery contracts providing for payment and delivery on the date or dates stated in the prospectus supplement. The identity of any such agents, the terms of such delayed delivery contracts and the commissions payable by us to these agents will be set forth in an applicable prospectus supplement.

If indicated in an applicable prospectus supplement, we may sell shares of our common stock under a newly established direct stock purchase and dividend reinvestment plan. The terms of any such plan will be set forth in the applicable prospectus supplement.

Each underwriter, dealer and agent participating in the distribution of any of the securities that are issuable in bearer form will agree that it will not offer, sell or deliver, directly or indirectly, securities in bearer form in the United States or to U.S. persons, other than qualifying financial institutions, during the restricted period, as defined in U.S. Treasury Regulations Section 1.163-5(c)(2)(i)(D)(7).

Except for shares of our common stock or as otherwise described in an applicable prospectus supplement, all of the securities will be a new issue of securities with no established trading market. Any underwriters to whom or agents through whom the securities are sold by us for public offering and sale may make a market in the securities, but such underwriters or agents 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 such securities.

Certain of the underwriters, dealers or agents and their associates may be customers of, engage in transactions with and perform services for us and our subsidiaries in the ordinary course of business.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities offered by us will be passed upon for us by Elliot S. Davis, Senior Vice President, General Counsel, Chief Compliance Officer and Corporate Secretary of Allegheny Technologies Incorporated, or by K&L Gates LLP, Pittsburgh, Pennsylvania. Mr. Davis is paid a salary by Allegheny Technologies Incorporated, is a participant in various employee benefit plans offered to its employees and beneficially owns, or has rights to acquire, an aggregate of less than one percent of the shares of our outstanding common stock.

EXPERTS

The consolidated financial statements of Allegheny Technologies Incorporated and Subsidiaries appearing in Allegheny Technologies Incorporated’s Annual Report (Form 10-K) for the year ended December 31, 2017 and the effectiveness of Allegheny Technologies Incorporated and Subsidiaries’ internal control over financial reporting as of December 31, 2017, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements and Allegheny Technologies Incorporated management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2017 are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The expenses (other than underwriting compensation) to be incurred by the registrant in connection with the issuance and distribution of the securities being registered under this registration statement are:

Securities and Exchange Commission Registration Fee	$	*
Trustees’ Fees and Expenses		*
Accounting Fees and Expenses		*
Printing and Engraving expenses		*
Rating Agency Fees		*
Legal Fees and Expenses		*
Miscellaneous		*
Total	$	*

* Deferred in accordance with Rules 456(b) and 457(r) of the Securities Act of 1933, as amended.

** Estimated expenses are not presently known. The foregoing sets forth the general categories of expenses (other than underwriting discounts and commissions) that we anticipate we will incur in connection with the offering of securities under this registration statement. Information regarding estimated expenses of issuance and distribution of each identified class of securities being registered will be provided at the time information as to such class is included in a prospectus supplement in accordance with Rule 430B.

Item 15. Indemnification of Directors and Officers

Section 102(b)(7) of the Delaware General Corporation Law (the “DGCL”) permits a corporation, in its certificate of incorporation, to limit or eliminate, subject to certain statutory limitations, the liability of directors to the corporation or its stockholders for monetary damages for breaches of fiduciary duty, except for liability (a) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (b) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (c) under Section 174 of the DGCL or (d) for any transaction from which the director derived an improper personal benefit. Our Restated Certificate of Incorporation provides, among other things, that the personal liability of our directors is so eliminated.

Under Section 145 of the DGCL, a corporation has the power to indemnify directors and officers under certain prescribed circumstances and subject to certain limitations against certain costs and expenses, including attorneys’ fees actually and reasonably incurred in connection with any action, suit or proceeding, whether civil, criminal, administrative or investigative, to which any of them is a party by reason of his being a director or officer of the corporation if it is determined that he acted in accordance with the applicable standard of conduct set forth in such statutory provision. Our Bylaws, as amended, provide that we will indemnify any person who may be involved, as a party or otherwise, in a claim, action, suit or proceeding (other than any claim, action, suit or proceeding brought by or in the right of Allegheny Technologies Incorporated) by reason of the fact that such person is or was a director or officer, or is or was serving at the request of us as a director or officer of any other corporation or entity, against certain liabilities, costs and expenses. We are also authorized to maintain insurance on behalf of any person who is or was a director or officer, or is or was serving at the request of us as a director or officer of any other corporation or entity, against any liability asserted against such person and incurred by such person in any such capacity or arising out of his status as such, whether or not we would have the power to indemnify such person against such liability under the DGCL. We are a party to agreements with our directors and officers pursuant to which we have agreed to indemnify them against certain costs and expenses incurred by them in their capacities as such.

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Item 16. Exhibits

Exhibit	Description
*1.1	Form of Underwriting Agreement.
*1.2	Form of Distribution Agreement.
4.1	Indenture dated as of December  15, 1995 between Allegheny Ludlum Corporation and The Chase Manhattan Bank (National Association), as trustee (incorporated by reference to Exhibit 4(a) to Allegheny Ludlum Corporation’s Annual Report on Form 10-K for the year ended December 31, 1995 (File No. 1-9498)), and First Supplemental Indenture by and among Allegheny Technologies Incorporated, Allegheny Ludlum Corporation and The Chase Manhattan Bank (National Association), as Trustee, dated as of August 15, 1996 (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K dated August 30, 1996 (File No. 1-12001)).
4.2	Supplemental Indenture, dated as of December  22, 2011, among Allegheny Ludlum Corporation, ALC Merger, LLC, and The Bank of New York Mellon (as successor to The Chase Manhattan Bank (National Association)), as trustee (incorporated by reference to Exhibit 4.4 to the Registrant’s Annual Report on Form 10-K for the year ended December 31, 2011 (File No. 1-12001)).
4.3	Indenture, dated June  1, 2009, between Allegheny Technologies Incorporated and The Bank of New York Mellon, as Trustee (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K dated June  3, 2009 (File No. 1-12001)).
4.4	Third Supplemental Indenture, dated January  7, 2011, between Allegheny Technologies Incorporated and The Bank of New York Mellon, as Trustee, relating to Allegheny Technologies Incorporated’s 5.950% Senior Notes due 2021 (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K dated January 7, 2011 (File No. 1-12001)).
4.5	Form of 5.950% Senior Note due 2021 (included in Exhibit 4.4).
4.6	Fourth Supplemental Indenture, dated July  12, 2013, between Allegheny Technologies Incorporated and The Bank of New York Mellon, as Trustee (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on Form 8-K dated July  12, 2013 (File No. 1-12001)).
4.7	Form of 5.875% Senior Note due 2023 (included in Exhibit 4.6).
4.8	Fifth Supplemental Indenture, dated May  24, 2016, between Allegheny Technologies Incorporated and The Bank of New York Mellon, as Trustee (incorporated by reference to Exhibit 4.2 to the Registrant’s Current Report on Form 8-K dated May  24, 2016 (File No. 1-12001)).
4.9	Form of 4.75% Convertible Senior Note due 2022 (included in Exhibit 4.8).
4.10	Form of Subordinated Debt Indenture (incorporated by reference to Exhibit 4.6 to the Registrant’s Registration Statement on Form S-3 (File No. 333-159479)).
4.11	Form of Senior Debt Security (included in Exhibit 4.3).
4.12	Form of Subordinated Debt Security (included in Exhibit 4.10).
*4.13	Form of Warrant Agreement.
*4.14	Form of Warrant Certificate.
*4.15	Form of Purchase Contract Agreement.
*4.16	Form of Purchase Contract Security.
*4.17	Form of Purchase Unit Agreement.
*4.18	Form of Purchase Unit Certificate.

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Exhibit	Description
*4.19	Form of Deposit Agreement.
*4.20	Form of Depositary Receipt.
4.21	Form of Certificate of Common Stock (incorporated by reference to Exhibit 6 to the Company’s Registration Statement on Form 8-A filed July 30, 1996 (File No. 1-12001)).
*4.22	Form of Certificate of Preferred Stock.
+5.1	Opinion of K&L Gates LLP.
12.1	Computation of Ratio of Earnings to Fixed Charges (incorporated by reference to Exhibit 12.1 to the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (File No. 1-12001).
+23.1	Consent of Ernst & Young LLP.
23.2	Consent of K&L Gates LLP (included in Exhibit 5.1).
24.1	Powers of Attorney (included on signature page).
+25.1	Form T-1 Statement of Eligibility of Senior Debt Indenture Trustee.
+25.2	Form T-1 Statement of Eligibility of Subordinated Debt Indenture Trustee.

* To be filed either by amendment to this Registration Statement or as an exhibit to a report filed under the Securities Exchange Act of 1934, as amended, and incorporated herein by reference.

+ Filed herewith.

Item 17. Undertakings

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933, as amended;

(ii) to reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) to include any material information with respect to the plan of distribution not previously disclosed in this registration statement or any material change to such information in this registration statement;

provided, however, that paragraphs (i), (ii) and (iii) do not apply if the registration statement is on Form S-3 and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, as amended, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act of 1933, as amended, to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act of 1933, as amended, shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which the prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof; provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933, as amended, to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6) That, for purposes of determining any liability under the Securities Act of 1933, as amended, each filing of Allegheny Technologies Incorporated’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934, as amended (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934, as amended), that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended, may be permitted to directors, officers and controlling persons of each registrant pursuant to the provisions described in Item 15 above, or otherwise, each registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act of 1933, as amended, and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by a registrant of expenses incurred or paid by a director, officer or controlling person of a registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, that registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933, as amended, and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, Allegheny Technologies Incorporated certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Pittsburgh, Commonwealth of Pennsylvania, on the 30^th day of April, 2018.

ALLEGHENY TECHNOLOGIES INCORPORATED
By:	/s/ Richard J. Harshman
Name:	Richard J. Harshman
Title:	Chairman, President and Chief Executive Officer

POWER OF ATTORNEY

Each of the undersigned directors and officers of Allegheny Technologies, Incorporated, a Delaware corporation, do hereby constitute and appoint Richard J. Harshman, Patrick J. DeCourcy and Elliot S. Davis, or any of them, the undersigned’s true and lawful attorneys and agents, with full power of substitution and resubstitution in each, to do any and all acts and things in our name and on our behalf in our respective capacities as directors and officers and to execute any and all instruments for us and in our names in the capacities indicated below, which said attorneys and agents, or either one of them, may deem necessary or advisable to enable said corporation to comply with the Securities Act, as amended, and any rules, regulations and requirements of the Securities and Exchange Commission, in connection with this Registration Statement, including specifically, but without limitation, power and authority to sign for us or any of us in our names in the capacities indicated below, any and all amendments (including post-effective amendments, whether pursuant to Rule 462(b) or otherwise) hereto, and each of the undersigned does hereby ratify and confirm all that said attorneys and agents, or either one of them or any substitute, shall do or cause to be done by virtue hereof. This Power of Attorney may be executed in any number of counterparts.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

SIGNATURE	TITLE	DATE
/s/ Richard J. Harshman Richard J. Harshman	Chairman, President and Chief Executive Officer (Principal Executive Officer)	April 30, 2018
/s/ Patrick J. DeCourcy Patrick J. DeCourcy	Senior Vice President, Finance and Chief Financial Officer (Principal Financial Officer)	April 30, 2018
/s/ Karl D. Schwartz Karl D. Schwartz	Vice President, Controller and Chief Accounting Officer (Principal Accounting Officer)	April 30, 2018
/s/ Herbert J. Carlisle Herbert J. Carlisle	Director	April 30, 2018
/s/ Carolyn Corvi Carolyn Corvi	Director	April 30, 2018
/s/ Diane C. Creel Diane C. Creel	Director	April 30, 2018

SIGNATURE	TITLE	DATE
/s/ James C. Diggs James C. Diggs	Director	April 30, 2018
/s/ J. Brett Harvey J. Brett Harvey	Director	April 30, 2018
/s/ Barbara S. Jeremiah Barbara S. Jeremiah	Director	April 30, 2018
/s/ David J. Morehouse David J. Morehouse	Director	April 30, 2018
/s/ John R. Pipski John R. Pipski	Director	April 30, 2018
/s/ James E. Rohr James E. Rohr	Director	April 30, 2018
/s/ John D. Turner John D. Turner	Director	April 30, 2018