INDENTURE

Exhibit 4.13

SBA COMMUNICATIONS CORPORATION

1.875% Convertible Senior Notes due 2013

INDENTURE

Dated as of May 16, 2008

U.S. BANK NATIONAL ASSOCIATION

Trustee

TABLE OF CONTENTS

- i -

- ii -

- iii -

- iv -

INDENTURE dated as of May 16, 2008 between SBA COMMUNICATIONS CORPORATION, a Florida corporation, as issuer (the “ Company ”), and U.S. BANK NATIONAL ASSOCIATION, a national banking association organized under the laws of the United States, as trustee (the “ Trustee ”).

WHEREAS, the Company has duly authorized the creation of an issue of its 1.875% Convertible Senior Notes due 2013 (the “ Notes ”), having the terms, tenor, amount and other provisions hereinafter set forth, and, to provide therefor, the Company has duly authorized the execution and delivery of this Indenture; and

WHEREAS, all things necessary to make the Notes, when the Notes are duly executed by the Company and authenticated and delivered hereunder and duly issued by the Company, the valid obligations of the Company, and to make this Indenture a valid and binding agreement of the Company, in accordance with their and its terms, have been done and performed, and the execution of this Indenture and the issue hereunder of the Notes have in all respects been duly authorized,

NOW, THEREFORE, THIS INDENTURE WITNESSETH:

For and in consideration of the premises and the purchase of the Notes by the holders thereof, it is mutually covenanted and agreed, for the equal and proportionate benefit of all holders of the Notes, as follows:

ARTICLE 1

Definitions and Incorporation by Reference

SECTION 1.01.  Definitions . The terms defined in this Section 1.01 (except as herein otherwise expressly provided or unless the context otherwise requires) for all purposes of this Indenture and of any indenture supplemental hereto shall have the respective meanings specified in this Section 1.01. All other terms used in this Indenture that are defined in the Trust Indenture Act or which are by reference therein defined in the Securities Act (except as herein otherwise expressly provided or unless the context otherwise requires) shall have the respective meanings assigned to such terms in the Trust Indenture Act and in the Securities Act as in force at the date of the execution of this Indenture. The words “ herein ”, “ hereof ”, “ hereunder ” and words of similar import refer to this Indenture as a whole and not to any particular Article, Section or other Subdivision. The terms defined in this Article include the plural as well as the singular.

“Additional Interest” has the meaning specified for Additional Interest in the Registration Rights Agreement.

“Additional Shares” has the meaning specified in Section 10.03.

“Adjustment Event” has the meaning specified in Section 10.04(k).

“Affiliate” of any specified Person means any other Person, directly or indirectly, controlling or controlled by or under direct or indirect common control with such specified

Person. For the purposes of this definition, “control” when used with respect to any Person means the power to direct the management and policies of such Person, directly or indirectly, whether through the ownership of voting securities, by contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

“Agent Members” has the meaning specified in Section 2.08(b)(vi).

“Bankruptcy Law” has the meaning specified in Section 6.01.

“Bid Solicitation Agent” means the financial institution appointed by the Company to solicit bids for the Trading Price of the Notes in accordance with Section 10.01(2). The Bid Solicitation Agent appointed by the Company shall initially be the Trustee.

“Board of Directors” means the Board of Directors of the Company or, other than in the case of the definition of “Continuing Directors,” any committee thereof duly authorized to act on behalf of such Board.

“Business Day” has the meaning specified in Section 11.08.

“Capital Stock” of any Person means any and all shares, interests, rights to purchase, warrants, options, participations or other equivalents of or interests in (however designated) equity of such Person, including any Preferred Stock, but excluding any debt securities convertible into such equity.

“close of business” means 5:00 p.m. (New York City time).

“Code” means the Internal Revenue Code of 1986, as amended.

“Common Equity” of any Person means Capital Stock of such Person that is generally entitled to (i) vote in the election of directors of such Person or (ii) if such Person is not a corporation, vote or otherwise participate in the selection of the governing body, partners, managers or others that will control the management or policies of such Person.

“Common Stock” means the Class A Common Stock, par value $0.01 per share, of the Company, or such other capital stock into which the Company’s common stock is reclassified or changed.

“Company” means the party named as such in this Indenture until a successor replaces it and, thereafter, means the successor and, for purposes of any provision contained herein and required by the Trust Indenture Act, each other obligor on the indenture securities.

“Continuing Director” means a director who either was a member of the Board of Directors on May 12, 2008 or who becomes a director of the Company subsequent to that date and whose election, appointment or nomination for election by the stockholders of the Company, is duly approved by a majority of the Continuing Directors on the Board of Directors at the time of such approval, either by a specific vote or by approval of the proxy statement issued by the Company on behalf of the entire Board of Directors in which such individual is named as nominee for director.

- 2 -

“Conversion Agent” means the agency appointed by the Company to which Notes may be presented for conversion. The Conversion Agent appointed by the Company shall initially be the Trustee.

“Conversion Date” has the meaning specified in Section 10.02(a).

“Conversion Notice” has the meaning specified in Section 10.02(a).

“Conversion Obligation” has the meaning specified in Section 10.01.

“Conversion Price” on any date of determination means $1,000 divided by the Conversion Rate as of such date.

“Conversion Rate” has the meaning specified in Section 10.01.

“Conversion Value,” for every $1,000 principal amount of a Note being converted, means an amount equal to the sum of the Daily Conversion Values for each of the forty-five (45) Settlement Period Trading Days in the Settlement Period.

“Corporate Trust Office” or other similar term, means the designated office of the Trustee at which at any particular time its corporate trust business as it relates to this Indenture shall be administered, which office is, at the date as of which this Indenture is dated, located at 100 Wall Street, Suite 1600, New York, New York 10005, Attention: Corporate Trust Administration or at any other time at such other address as the Trustee may designate from time to time by notice to the Company.

“Current Market Price” means the average of the Last Reported Sale Prices of the Common Stock over the ten (10) consecutive Trading-Day period ending on the Trading Day immediately preceding the declaration date for the distribution requiring such computation.

“Custodian” has the meaning specified in Section 6.01.

“Daily Conversion Value” for any Settlement Period Trading Day equals 1/45th of (x) the Conversion Rate in effect on that Settlement Period Trading Day multiplied by (y) the VWAP of the Common Stock on that Settlement Period Trading Day.

“declaration date” and “date of declaration” shall mean, with respect to a distribution by the Company to all or substantially all of its holders of Common Stock, the date on which the distribution has been authorized by the Board of Directors under applicable law.

“Default” means any event which is, or after notice or passage of time or both would be, an Event of Default.

“Defaulted Interest” has the meaning specified in Section 2.13.

“Depositary” means the clearing agency registered under the Exchange Act that is designated to act as the Depositary for the Global Notes. DTC shall be the initial Depositary, until a successor shall have been appointed and become such pursuant to the applicable provisions of this Indenture, and thereafter, “Depositary” shall mean or include such successor.

- 3 -

“Determination Date” has the meaning specified in Section 10.04(k).

“Distributed Property” has the meaning specified in Section 10.04(c).

“DTC” means The Depository Trust Company.

“Effective Date” has the meaning specified in Section 10.03.

“Event of Default” has the meaning specified in Section 6.01.

“Exchange Act” means the Securities Exchange Act of 1934, as amended.

“Ex-Dividend Date” means, in respect of a dividend or distribution to holders of Common Stock, the first date upon which a sale of the Common Stock does not automatically transfer the right to receive the relevant dividend or distribution from the seller of the Common Stock to its buyer.

“Expiration Date” has the meaning specified in Section 10.04(e).

“Expiration Time” has the meaning specified in Section 10.04(e).

“Fair Market Value” means the amount that a willing buyer would pay to a willing seller in an arms’ length transaction, as determined by the Board of Directors.

“Fixed Cash Amount” has the meaning specified in Section 10.02(b).

“Full Interest Period” means a period of days during which interest accrues from, and including, an Interest Payment Date to, but excluding, the next Interest Payment Date.

“Fundamental Change” shall be deemed to have occurred at such time after the original issuance of the Notes that any of the following occurs:

(i) any “person” or “group” (within the meaning of Section 13(d) of the Exchange Act), other than the Company, its Subsidiaries or the employee benefit plans of the Company or any such Subsidiary of the Company, files a Schedule TO or any schedule, form or report under the Exchange Act disclosing that such person or group has become the direct or indirect ultimate “beneficial owner,” as defined in Rule 13d-3 under the Exchange Act, of the Company’s Common Equity representing more than 50% of the voting power of the Company’s Common Equity;

(ii) consummation of any share exchange, consolidation or merger of the Company pursuant to which the Common Stock will be converted into cash, securities or other property or any conveyance, transfer, sale, lease or other disposition in one transaction or a series of transactions of all or substantially all of the consolidated assets of the Company and its Subsidiaries, taken as a whole, to any Person other than one of

- 4 -

the Company’s Subsidiaries; provided , however , that a transaction where the holders of more than 50% of all classes of the Company’s Common Equity immediately prior to such transaction own, directly or indirectly, more than 50% of all classes of Common Equity of the continuing or surviving corporation or transferee immediately after such event shall not be a Fundamental Change;

(iii) Continuing Directors cease to constitute at least a majority of the Board of Directors;

(iv) the stockholders of the Company approve any plan or proposal for the liquidation or dissolution of the Company; or

(v) the Common Stock (or other common stock into which the Notes are then convertible) ceases to be quoted or listed on a national securities exchange or quoted on the Nasdaq Global Select Market, Nasdaq Global Market or another established automated over-the-counter trading market in the United States;

provided , however , that a Fundamental Change shall not be deemed to have occurred if at least 95% of the consideration, excluding cash payments for fractional shares, in the transaction or transactions constituting the Fundamental Change consists of shares of Publicly Traded Securities, and as a result of such transaction or transactions, the Notes become convertible into such Publicly Traded Securities in accordance with Section 10.05, subject to the provisions of Section 10.02.

For purposes of this definition, whether a “person” is a “beneficial owner” shall be determined in accordance with Rule 13d-3 under the Exchange Act and “person” includes any syndicate or group that would be deemed to be a “person” under Section 13(d)(3) of the Exchange Act.

“Fundamental Change Company Notice” has the meaning specified in Section 3.01(b).

“Fundamental Change Repurchase Date” has the meaning specified in Section 3.01(a).

“Fundamental Change Repurchase Expiration Time” has the meaning specified in Section 3.01(a)(1).

“Fundamental Change Repurchase Notice” has the meaning specified in Section 3.01(a)(1).

“Fundamental Change Repurchase Price” has the meaning specified in Section 3.01(a).

“Global Notes” has the meaning specified in Section 2.02.

“Indenture” means this Indenture as amended or supplemented from time to time.

- 5 -

“Initial Purchasers” means each of Deutsche Bank Securities Inc., Citigroup Global Markets Inc., Lehman Brothers Inc., J.P. Morgan Securities Inc., Wachovia Capital Markets, LLC, Greenwich Capital Markets, Inc. and TD Securities (USA) LLC (each, an “Initial Purchaser”).

“interest” means, when used with reference to the Notes, any interest payable under the terms of the Notes, including Defaulted Interest, if any, Additional Interest, if any, and Reporting Additional Interest, if any.

“Interest Payment Date” has the meaning specified in Section 2.03(c).

“Last Reported Sale Price” of the Common Stock on any date means:

(i) the closing sale price per share (or if no closing sale price is reported, the average of the bid and ask prices or, if more than one in either case, the average of the average bid and the average asked prices) on that date as reported by the Nasdaq Global Select Market or the Nasdaq Global Market; or

(ii) if the Common Stock is not quoted on the Nasdaq Global Select Market or the Nasdaq Global Market, the closing sale price per share (or if no closing sale price is reported, the average of the bid and ask prices or, if more than one in either case, the average of the average bid and the average asked prices) on that date as reported in composite transactions for the principal U.S. national or regional securities exchange on which the Common Stock is traded; or

(iii) if the Common Stock is not listed for trading on a U.S. national or regional securities exchange, the last quoted bid price for the Common Stock in the over-the-counter market on that date as reported by Pink Sheets LLC or similar organization; or

(iv) if the Common Stock is not so quoted by Pink Sheets LLC or similar organization, the average of the mid-point of the last bid and ask prices for the Common Stock on the relevant date from a nationally recognized independent investment banking firm selected by the Company for this purpose.

The Last Reported Sale Price of the Common Stock will be determined without reference to extended or after hours trading. If during a period applicable for calculating the Last Reported Sale Price of the Common Stock an event occurs that requires an adjustment to the Conversion Rate, the Last Reported Sale Price shall be calculated for such period in a manner determined by the Board of Directors of the Company to appropriately reflect the impact of such event on the price of the Common Stock during such period.

“Make-Whole Fundamental Change” means any transaction or event that constitutes a Fundamental Change as described in clauses (i), (ii), (iv) and (v) of the definition thereof, except that the entire “provided however” proviso in clause (ii) of the definition of Fundamental Change shall be disregarded and shall not be given effect for purposes of determining whether a transaction or event is a Make-Whole Fundamental Change.

- 6 -

“Market Disruption Event” means, if the Common Stock is quoted on the Nasdaq Global Select Market or the Nasdaq Global Market or listed on another U.S. national or regional securities exchange, the occurrence or existence during the one-half hour period ending on the scheduled close of trading on any Trading Day of any material suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the stock exchange or otherwise) in the Common Stock or in any options, contracts or future contracts relating to the Common Stock.

“Maturity Date” means May 1, 2013.

“Noteholder” or “Holder” means the Person in whose name a Note is registered on the Registrar’s books.

“Notes” means any Notes issued, authenticated and delivered under this Indenture, including any Global Notes.

“Officer” means the Chairman of the Board, the Chief Executive Officer, the Chief Financial Officer, the President, any Vice President, the Treasurer, any Assistant Treasurer, the Secretary or any Assistant Secretary of the Company.

“Officers’ Certificate” means a certificate signed by two Officers. One of the officers executing an Officers’ Certificate in accordance with Section 4.06 shall be the chief executive officer, chief financial officer or chief operating officer of the Company.

“opening of business” means 9:00 a.m. (New York City time).

“Opinion of Counsel” means a written opinion from legal counsel who is acceptable to the Trustee. The counsel may be an employee of or counsel to the Company or the Trustee.

“Paying Agent” has the meaning specified in Section 2.05.

“Person” means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization, government or any agency or political subdivision thereof or any other entity.

“PORTAL ^SM Market” means The PORTAL Market operated by the Nasdaq Stock Market LLC or any successor thereto.

“Preferred Stock”, as applied to the Capital Stock of any Person, means Capital Stock of any class or classes (however designated) that is preferred as to the payment of dividends, or as to the distribution of assets upon any voluntary or involuntary liquidation or dissolution of such Person, over shares of Capital Stock of any other class of such Person.

“protected purchaser” has the meaning specified in Section 2.09.

“Publicly Traded Securities” means shares of common stock listed on a national securities exchange or quoted on the Nasdaq Global Select Market or the Nasdaq Global Market that will be so listed or quoted when issued or exchanged in connection with a Fundamental Change.

- 7 -

“Record Date” means, in respect of a dividend or distribution to holders of Common Stock, the date fixed for determination of holders of Common Stock entitled to receive such dividend or distribution.

“Reference Property” has the meaning specified in Section 10.05.

“Register” has the meaning specified in Section 2.05.

“Registrar” has the meaning specified in Section 2.05.

“Registration Rights Agreement” means the Registration Rights Agreement, dated as of May 16, 2008, between the Company and the Representatives, as amended from time to time in accordance with its terms.

“Regular Record Date” means, with respect to any Interest Payment Date of the Notes, the April 15 and October 15 preceding the applicable May 1 and November 1 Interest Payment Date, respectively.

“Reorganization Event” has the meaning specified in Section 10.05.

“Reporting Additional Interest” has the meaning specified in Section 6.12.

“Representatives” means, with respect to the Initial Purchasers, Deutsche Bank Securities Inc., Citigroup Global Markets Inc. and Lehman Brothers Inc.

“Responsible Officer” shall mean, when used with respect to the Trustee, any officer within the corporate trust department of the Trustee with direct responsibility for the administration of this Indenture and also means, with respect to a particular corporate trust matter, any other officer to whom such matter is referred because of such person’s knowledge of or familiarity with the particular subject.

“Restricted Securities” has the meaning specified in Section 2.08(c).

“Rule 144A” means Rule 144A as promulgated under the Securities Act as it may be amended from time to time hereafter.

“Schedule TO” means a Tender Offer Statement under Section 14(d)(1) or 13(e)(1) of the Exchange Act.

“Scheduled Trading Day” means any day on which the primary U.S. national securities exchange or market on which the Common Stock is listed or admitted for trading is scheduled to be open for trading.

“SEC” means the Securities and Exchange Commission.

“Securities Act” means the Securities Act of 1933, as amended.

- 8 -

“Settlement Period” means the forty-five (45) consecutive Settlement Period Trading Days:

(i) with respect to Conversion Dates occurring during the period beginning fifty (50) Scheduled Trading Days preceding the Maturity Date, beginning on and including the forty-seventh (47 ^th ) Scheduled Trading Day immediately preceding the Maturity Date; and

(ii) in all other cases, beginning on and including the third (3 ^rd ) Trading Day following the Conversion Date.

“Settlement Period Market Disruption Event” means:

(i) a failure by the primary U.S. national securities exchange or market on which the Common Stock is listed or admitted to trading to open for trading during its regular trading session; or

(ii) the occurrence or existence prior to 1:00 p.m. on any Trading Day for the Common Stock of an aggregate one half hour period, of any suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the stock exchange or otherwise) in the Common Stock or in any options, contracts or future contracts relating to the Common Stock.

“Settlement Period Trading Day” means a day during which:

(i) trading in the Common Stock generally occurs on the primary U.S. national securities exchange or market on which the Common Stock is listed or admitted for trading; and

(ii) there is no Settlement Period Market Disruption Event;

provided , however , that if on any Trading Day the Common Stock is not traded on any market, then that Trading Day shall nevertheless be a “Settlement Period Trading Day” so long as the market value per share of the Common Stock on that Trading Day can be obtained from a nationally recognized independent investment banking firm retained for these purposes by the Company.

“Significant Subsidiary” means any Subsidiary of the Company that would be a “Significant Subsidiary” of the Company within the meaning of Rule 1-02(w) under Regulation S-X promulgated by the SEC.

“Special Interest Payment Date” has the meaning specified in Section 2.13(a).

“Special Record Date” has the meaning specified in Section 2.13(a).

“Spin-off” has the meaning specified in Section 10.04(c).

“Stock Price” means:

(i) in the case of a Make-Whole Fundamental Change in which holders of the Common Stock receive only cash as consideration for their shares of Common Stock, the amount of cash paid per share of the Common Stock in such Make-Whole Fundamental Change; or

- 9 -

(ii) in the case of all other Make-Whole Fundamental Changes, the average of the Last Reported Sale Prices of Common Stock over the five (5) consecutive Trading-Day period ending on the Trading Day immediately preceding the Effective Date of such Make-Whole Fundamental Change.

“Stock Price Measurement Period” has the meaning specified in Section 10.01(1).

“Subsidiary” of any Person means any corporation, association, partnership or other business entity of which more than 50% of the total voting power of shares of Capital Stock or other interests (including partnership interests) entitled (without regard to the occurrence of any contingency) to vote in the election of directors, managers or trustees thereof is at the time owned or controlled, directly or indirectly, by (i) such Person, (ii) such Person and one or more Subsidiaries of such Person or (iii) one or more Subsidiaries of such Person.

“Successor Company” has the meaning specified in Section 5.01(a).

“Trading Day” means a day during which:

(i) the Nasdaq Global Select Market or the Nasdaq Global Market is open for trading, or if the Common Stock is not quoted on the Nasdaq Global Select Market or the Nasdaq Global Market, the principal U.S. national or regional securities exchange on which the Common Stock is listed is open for trading, or if the Common Stock is not so quoted or listed, any Business Day; and

(ii) there is no Market Disruption Event.

“Trading Price” per $1,000 principal amount of Notes on any date of determination shall be calculated based on the average of the secondary market bid quotations obtained by the Bid Solicitation Agent for $5,000,000 aggregate principal amount of Notes at approximately 3:30 p.m., New York City time, on such determination date from three independent nationally recognized securities dealers selected by the Company; provided that, if only two such bids can reasonably be obtained, then the average of the two bids shall be used, and if only one such bid can reasonably be obtained, then that one bid shall be used. If the Bid Solicitation Agent cannot reasonably obtain at least one bid for $5,000,000 aggregate principal amount of Notes, then the Trading Price per $1,000 principal amount of Notes will be deemed to be less than 95% of the product of the Last Reported Sale Price of the Common Stock and the applicable Conversion Rate.

“Trading Price Measurement Period” has the meaning specified in Section 10.01(2).

“Trust Indenture Act” means the Trust Indenture Act of 1939 (15  U.S.C. §§ 77aaa-77bbbb), as amended, as in effect on the date of this Indenture.

- 10 -

“Trust Officer” means any officer within the Corporate Trust Office of the Trustee with direct responsibility for the administration of this Indenture.

“Trustee” means the party named as such in this Indenture until a successor replaces it and, thereafter, means the successor.

“Uniform Commercial Code” means the New York Uniform Commercial Code as in effect from time to time.

“VWAP” for the Common Stock means, with respect to any Settlement Period Trading Day during the Settlement Period, the per share volume-weighted average price of the Common Stock as displayed under the heading “Bloomberg VWAP” on Bloomberg page SBAC.UQ <equity> AQR in respect of the period from 9:30 a.m. to 4:00 p.m., New York City time, on such Settlement Period Trading Day; or if such volume-weighted average price is unavailable, the market value per share of the Common Stock on such Settlement Period Trading Day as determined by a nationally recognized independent investment banking firm retained for this purpose by the Company.

“Wholly Owned Subsidiary” means a Subsidiary of the Company, all the Capital Stock of which (other than directors’ qualifying shares) is owned by the Company or another Wholly Owned Subsidiary.

SECTION 1.02.  Incorporation by Reference of Trust Indenture Act . This Indenture is subject to the mandatory provisions of the Trust Indenture Act, which are incorporated by reference in and made a part of this Indenture. The following Trust Indenture Act terms have the following meanings:

“Commission” means the SEC.

“indenture securities” means the Notes.

“indenture security holder” means a Noteholder.

“indenture to be qualified” means this Indenture.

“indenture trustee” or “institutional trustee” means the Trustee.

“obligor” on the indenture securities means the Company and any other obligor on the indenture securities.

All other Trust Indenture Act terms used in this Indenture that are defined by the Trust Indenture Act, defined by Trust Indenture Act reference to another statute or defined by SEC rule have the meanings assigned to them by such definitions.

SECTION 1.03.  Rules of Construction . Unless the context otherwise requires:

(1) a term has the meaning assigned to it;

- 11 -

(2) “or” is not exclusive;

(3) “including” means including without limitation; and

(4) words in the singular include the plural and words in the plural include the singular.

ARTICLE 2

The Notes

SECTION 2.01.  Designation, Amount and Issuance of Notes . The Notes shall be designated as “1.875% Convertible Senior Notes due 2013.” The Notes will not exceed the aggregate principal amount of $550,000,000 (except pursuant to Sections 2.04, 2.11 and 3.03 hereof). Upon the execution of this Indenture, or from time to time thereafter, Notes may be executed by the Company and delivered to the Trustee for authentication.

SECTION 2.02.  Form of the Notes . The Notes and the Trustee’s certificate of authentication to be borne by such Notes shall be substantially in the form set forth in Exhibit A hereto. The terms and provisions contained in the form of Notes attached as Exhibit A hereto shall constitute, and are hereby expressly made, a part of this Indenture and, to the extent applicable, the Company and the Trustee, by their execution and delivery of this Indenture, expressly agree to such terms and provisions and to be bound thereby.

Any of the Notes may have such letters, numbers or other marks of identification and such notations, legends, endorsements or changes as the officers executing the same may approve (execution thereof to be conclusive evidence of such approval) and as are not inconsistent with the provisions of this Indenture, or as may be required by the custodian for the Global Notes, the Depositary or by The NASDAQ Stock Market LLC in order for the Notes to be tradable on The PORTAL ^SM Market or as may be required for the Notes to be tradable on any other market developed for trading of securities pursuant to Rule 144A or as may be required to comply with any applicable law or with any rule or regulation made pursuant thereto or with any rule or regulation of any securities exchange or automated quotation system on which the Notes may be listed, or to conform to usage, or to indicate any special limitations or restrictions to which any particular Notes are subject.

So long as the Notes are eligible for book-entry settlement with the Depositary, or unless otherwise required by law, or otherwise contemplated by Section 2.08(b), all of the Notes will be represented by one or more Notes in global form registered in the name of the Depositary or the nominee of the Depositary (the “ Global Notes ”). The transfer and exchange of beneficial interests in any such Global Notes shall be effected through the Depositary in accordance with this Indenture and the applicable procedures of the Depositary. Except as provided in Section 2.08(b), beneficial owners of a Global Note shall not be entitled to have certificates registered in their names, will not receive or be entitled to receive physical delivery of certificates in definitive form and will not be considered holders of such Global Note.

- 12 -

Any Global Notes shall represent such of the outstanding Notes as shall be specified therein and shall provide that it shall represent the aggregate amount of outstanding Notes from time to time endorsed thereon and that the aggregate amount of outstanding Notes represented thereby may from time to time be increased or reduced to reflect repurchases, conversions, transfers or exchanges permitted hereby. Any endorsement of a Global Note to reflect the amount of any increase or decrease in the amount of outstanding Notes represented thereby shall be made by the Trustee or the custodian for the Global Note, at the direction of the Trustee, in such manner and upon instructions given by the holder of such Notes in accordance with this Indenture. Payment of principal of, interest on and premium, if any, on any Global Notes shall be made to the Depositary in immediately available funds.

SECTION 2.03.  Date and Denomination of Notes; Payment at Maturity; Payment of Interest .

(a) Date and Denomination . The Notes shall be issuable in registered form without coupons in denominations of $1,000 principal amount and integral multiples thereof. Each Note shall be dated the date of its authentication and shall bear interest from the date specified on the face of the form of Notes attached as Exhibit A hereto.

(b) Payment at Maturity . The Notes shall mature on May 1, 2013, unless earlier converted or repurchased in accordance with the provisions hereof. On the Maturity Date, each Holder shall be entitled to receive on such date $1,000 in cash for each $1,000 principal amount of Notes, together with accrued and unpaid interest to, but not including, the Maturity Date. With respect to Global Notes, principal and interest will be paid to the Depositary in immediately available funds. With respect to any certificated Notes, principal and interest will be payable at the Company’s office or agency in New York City, which initially will be the office or agency of the Trustee located at 100 Wall Street, Suite 1600, New York, New York 10005, Attention: Corporate Trust Administration and at the Company’s office or agency in Miami, Florida, which initially will be the office or agency of the Trustee located at 200 South Biscayne Blvd., Suite 1870, Miami, Florida 33131, Attention: Corporate Trust Administration. If the Maturity Date is not a Business Day, payment shall be made on the next succeeding Business Day, and no additional interest shall be accrue thereon.

(c) Payment of Interest . Interest on the Notes will accrue at the rate of 1.875% per annum, from May 16, 2008 until the principal thereof is paid or made available for payment. Interest shall be payable on May 1 and November 1 of each year (each, an “ Interest Payment Date ”), commencing November 1, 2008, to the Person in whose name any Note is registered on the Register at the close of business on any Regular Record Date with respect to the applicable Interest Payment Date, except that the interest payable on the Maturity Date will be paid to the Person to whom the principal amount is paid. Notwithstanding the foregoing, any Notes or portion thereof surrendered for conversion after the close of business on the Regular Record Date for an Interest Payment Date but prior to the applicable Interest Payment Date shall be accompanied by payment, in immediately available funds or other funds acceptable to the Company, of an amount equal to the interest otherwise payable on such Interest Payment Date on the principal amount being converted; provided that no such payment need be made:

(i) with respect to conversions after the close of business on April 15, 2013;

- 13 -

(ii) with respect to conversions during such period commencing on the date the Company has given notice of a Fundamental Change pursuant to Section 10.01(4) to, and including, the second Scheduled Trading Day immediately preceding the corresponding Fundamental Change Repurchase Date; or

(iii) with respect to any overdue interest, if overdue interest exists at the time of conversion with respect to such Notes.

Interest on the Notes for a Full Interest Period will be computed on the basis of a three-hundred sixty (360)-day year comprised of twelve (12) thirty (30)-day months. Interest on the Notes for a period other than a Full Interest Period will be calculated on the basis of the actual number of days elapsed during the period and a three-hundred sixty-five (365)-day year.

The Company shall pay interest on:

(i) any Global Notes by wire transfer of immediately available funds to the account of the Depositary or its nominee;

(ii) any Notes in certificated form having a principal amount of less than $5,000,000, by check mailed to the address of the Person entitled thereto as it appears in the Register, provided , however , that, at maturity, interest will be payable as described in Section 2.03(b); and

(iii) any Notes in certificated form having a principal amount of $5,000,000 or more, by wire transfer in immediately available funds at the election of the holder of such Notes duly delivered to the trustee at least five (5) Business Days prior to the relevant Interest Payment Date, provided , however , that, at maturity, interest will be payable as described in Section 2.03(b).

If an Interest Payment Date is not a Business Day, payment shall instead be made on the next succeeding Business Day, and no additional interest shall accrue thereon.

SECTION 2.04.  Execution and Authentication . One Officer shall sign the Notes for the Company by manual or facsimile signature. If an Officer whose signature is on a Note no longer holds that office at the time the Trustee authenticates the Note, the Note shall be valid nevertheless.

A Note shall not be valid until an authorized signatory of the Trustee manually authenticates the Note. Upon the written order of the Company signed by an Officer, the Trustee shall authenticate a Note executed by the Company. The signature of the Trustee on the Note shall be conclusive evidence that the Note has been duly and validly authenticated under this Indenture. A Note shall be dated the date of its authentication.

The Trustee may appoint an authenticating agent reasonably acceptable to the Company to authenticate the Notes. Any such appointment shall be evidenced by an instrument signed by a Trust Officer, a copy of which shall be furnished to the Company. Unless limited by the terms of such appointment, an authenticating agent may authenticate Notes whenever the Trustee may do so. Each reference in this Indenture to authentication by the Trustee includes authentication by such agent. An authenticating agent has the same rights as any Registrar, Paying Agent or agent for service of notices and demands.

- 14 -

SECTION 2.05.  Registrar and Paying Agent . The Company shall maintain an office or agency where Notes may be presented for registration of transfer or for exchange (the “ Registrar ”) and an office or agency where Notes may be presented for payment (the “ Paying Agent ”). The Corporate Trust Office shall be considered as one such office or agency of the Company for each of the aforesaid purposes. The Registrar shall keep a register of the Notes (the “ Register ”) and of their transfer and exchange. The Company may have one or more co-registrars and one or more additional paying agents. The term “Paying Agent” includes any additional paying agent, and the term “Registrar” includes any co-registrars. The Company initially appoints the Trustee as (i) Registrar and Paying Agent in connection with the Notes, (ii) the custodian with respect to the Global Notes, (iii) Conversion Agent and (iv) Bid Solicitation Agent.

The Company shall enter into an appropriate agency agreement with any Registrar or Paying Agent not a party to this Indenture, which shall incorporate the terms of the Trust Indenture Act. The agreement shall implement the provisions of this Indenture that relate to such agent. The Company shall notify the Trustee of the name and address of any such agent. If the Company fails to maintain a Registrar or Paying Agent, the Trustee shall act as such and shall be entitled to appropriate compensation therefor pursuant to Section 7.07. The Company or any of its domestically organized Wholly Owned Subsidiaries may act as Paying Agent or Registrar.

The Company may remove any Registrar or Paying Agent upon written notice to such Registrar or Paying Agent and to the Trustee; provided , however , that no such removal shall become effective until (1) acceptance of an appointment by a successor as evidenced by an appropriate agreement entered into by the Company and such successor Registrar or Paying Agent, as the case may be, and delivered to the Trustee or (2) notification to the Trustee that the Trustee shall serve as Registrar or Paying Agent until the appointment of a successor in accordance with clause (1) above. The Registrar or Paying Agent may resign at any time upon written notice; provided , however , that the Trustee may resign as Paying Agent or Registrar only if the Trustee also resigns as Trustee in accordance with Section 7.08.

SECTION 2.06.  Paying Agent to Hold Money in Trust . Prior to each due date of the principal and interest on any Note, the Company shall deposit with the Paying Agent (or if the Company or a Subsidiary of the Company is acting as Paying Agent, segregate and hold in trust for the benefit of the Persons entitled thereto) a sum sufficient to pay such principal and interest when so becoming due. The Company shall require each Paying Agent (other than the Trustee) to agree in writing that the Paying Agent shall hold in trust for the benefit of Noteholders or the Trustee all money held by the Paying Agent for the payment of principal of or interest on the Notes and shall notify the Trustee of any default by the Company in making any such payment. If the Company or a Subsidiary of the Company acts as Paying Agent, it shall segregate the money held by it as Paying Agent and hold it as a separate trust fund. The Company at any time may require a Paying Agent to pay all money held by it to the Trustee and to account for any funds disbursed by the Paying Agent. Upon complying with this Section, the Paying Agent shall have no further liability for the money delivered to the Trustee.

- 15 -

SECTION 2.07.  Noteholder Lists . The Trustee shall preserve in as current a form as is reasonably practicable the most recent list available to it of the names and addresses of Noteholders and shall otherwise comply with Section 312(a) of the Trust Indenture Act. If the Trustee is not the Registrar, or to the extent otherwise required under the Trust Indenture Act, the Company shall furnish, or cause the Registrar to furnish, to the Trustee, in writing at least five (5) Business Days before each Interest Payment Date and at such other times as the Trustee may request in writing, a list in such form and as of such date as the Trustee may reasonably require of the names and addresses of Noteholders and the Company shall otherwise comply with Section 312(a) of the Trust Indenture Act.

SECTION 2.08.  Exchange and Registration of Transfer of Notes; Restrictions on Transfer . (a) The Company shall cause to be kept at the Corporate Trust Office the Register in which, subject to such reasonable regulations as it may prescribe, the Company shall provide for the registration of Notes and of transfers of Notes. The Register shall be in written form or in any form capable of being converted into written form within a reasonably prompt period of time.

Upon surrender for registration of transfer of any Notes to the Registrar or any co-registrar, and satisfaction of the requirements for such transfer set forth in this Section 2.08, the Company shall execute, and the Trustee shall authenticate and deliver, in the name of the designated transferee or transferees, one or more new Notes of any authorized denominations and of a like aggregate principal amount and bearing such restrictive legends as may be required by this Indenture.

Notes may be exchanged for other Notes of any authorized denominations and of a like aggregate principal amount, upon surrender of the Notes to be exchanged at any such office or agency maintained by the Company pursuant to Section 4.02. Whenever any Notes are so surrendered for exchange, the Company shall execute, and the Trustee shall authenticate and deliver, the Notes that the holder making the exchange is entitled to receive bearing registration numbers not contemporaneously outstanding.

All Notes issued upon any registration of transfer or exchange of Notes shall be the valid obligations of the Company, evidencing the same debt, and entitled to the same benefits under this Indenture, as the Notes surrendered upon such registration of transfer or exchange.

All Notes presented or surrendered for registration of transfer or for exchange, repurchase or conversion shall (if so required by the Company or the Registrar) be duly endorsed, or be accompanied by a written instrument or instruments of transfer in form satisfactory to the Company, and the Notes shall be duly executed by the holder thereof or his attorney duly authorized in writing.

No service charge shall be made to any holder for any registration of, transfer or exchange of Notes, but the Company or the Trustee may require payment by the holder of a sum sufficient to cover any tax, assessment or other governmental charge that may be imposed in connection with any registration of transfer or exchange of Notes.

- 16 -

Neither the Company nor the Trustee nor any Registrar shall be required to exchange, issue or register a transfer of (a) any Note or portions thereof surrendered for conversion pursuant to Article 10 or (b) any Note or portions thereof tendered for repurchase (and not withdrawn) pursuant to Article 3.

(b) The following provisions shall apply only to Global Notes:

(i) Each Global Note authenticated under this Indenture shall be registered in the name of the Depositary or a nominee thereof and delivered to such Depositary or a nominee thereof or custodian for the Global Notes therefor, and each such Global Note shall constitute a single Note for all purposes of this Indenture.

(ii) Notwithstanding any other provision in this Indenture, no Global Note may be exchanged in whole or in part for Notes registered, and no transfer of a Global Note in whole or in part may be registered, in the name of any Person other than the Depositary or a nominee thereof unless (A) the Depositary (x) has notified the Company that it is unwilling or unable to continue as Depositary for such Global Note or (y) has ceased to be a clearing agency registered under the Exchange Act, and a successor Depositary has not been appointed by the Company within ninety (90) calendar days, or (B) the Company, at its option, notifies the Trustee in writing that it no longer wishes to have all the Notes represented by Global Notes. Any Global Note exchanged pursuant to this Section 2.08(b)(ii) shall be so exchanged in whole and not in part.

(iii) In addition, certificated Notes will be issued in exchange for beneficial interests in a Global Note upon request by or on behalf of the Depositary in accordance with customary procedures following the request of a beneficial owner seeking to enforce its rights under the Notes or this Indenture, including its rights following the occurrence of an Event of Default.

(iv) Notes issued in exchange for a Global Note or any portion thereof pursuant to clause (ii) or (iii) above shall be issued in definitive, fully registered form, without interest coupons, shall have an aggregate principal amount equal to that of such Global Notes or portion thereof to be so exchanged, shall be registered in such names and be in such authorized denominations as the Depositary shall designate and shall bear any legends required hereunder. Any Global Notes to be exchanged shall be surrendered by the Depositary to the Trustee, as Registrar, provided that pending completion of the exchange of a Global Note, the Trustee acting as custodian for the Global Notes for the Depositary or its nominee with respect to such Global Notes, shall reduce the principal amount thereof, by an amount equal to the portion thereof to be so exchanged, by means of an appropriate adjustment made on the records of the Trustee. Upon any such surrender or adjustment, the Trustee shall authenticate and make available for delivery the Notes issuable on such exchange to or upon the written order of the Depositary or an authorized representative thereof.

- 17 -

(v) In the event of the occurrence of any of the events specified in clause (ii) above or upon any request described in clause (iii) above, the Company will promptly make available to the Trustee a sufficient supply of certificated Notes in definitive, fully registered form, without interest coupons.

(vi) Neither any members of, or participants in, the Depositary (the “ Agent Members ”) nor any other Persons on whose behalf Agent Members may act shall have any rights under this Indenture with respect to any Global Notes registered in the name of the Depositary or any nominee thereof, and the Depositary or such nominee, as the case may be, may be treated by the Company, the Trustee and any agent of the Company or the Trustee as the absolute owner and holder of such Global Notes for all purposes whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the Company, the Trustee or any agent of the Company or the Trustee from giving effect to any written certification, proxy or other authorization furnished by the Depositary or such nominee, as the case may be, or impair, as between the Depositary, its Agent Members and any other Person on whose behalf an Agent Member may act, the operation of customary practices of such Persons governing the exercise of the rights of a holder of any Notes.

(vii) At such time as all interests in a Global Note have been repurchased, converted, cancelled or exchanged for Notes in certificated form, such Global Note shall, upon receipt thereof, be canceled by the Trustee in accordance with standing procedures and instructions existing between the Depositary and the custodian for the Global Note. At any time prior to such cancellation, if any interest in a Global Note is repurchased, converted, cancelled or exchanged for Notes in certificated form, the principal amount of such Global Note shall, in accordance with the standing procedures and instructions existing between the Depositary and the custodian for the Global Note, be appropriately reduced, and an endorsement shall be made on such Global Note, by the Trustee or the custodian for the Global Note, at the direction of the Trustee, to reflect such reduction.

(c) Every Note (and all securities issued in exchange therefor or in substitution thereof) that bears or is required under this Section 2.08(c) to bear the Restricted Note Legend set forth in Exhibit A (together with any Common Stock issued upon conversion of the Notes and required to bear the legend set forth in Exhibit B, collectively, the “ Restricted Securities ”) shall be subject to the restrictions on transfer set forth in this Section 2.08(c) (including those set forth in the Restricted Note Legend in Exhibit A and the legend set forth in Exhibit B) unless such restrictions on transfer shall be waived by written consent of the Company following receipt of legal advice supporting the permissibility of the waiver of such transfer restrictions, and the holder of each such Restricted Security, by such holder’s acceptance thereof, agrees to be bound by all such restrictions on transfer. As used in this Section 2.08(c), the term “transfer” means any sale, pledge, loan, transfer or other disposition whatsoever of any Restricted Security or any interest therein.

- 18 -

Until one year after the last date of original issuance of the Notes, any certificate evidencing a Restricted Security shall bear a legend in substantially the form set forth in Exhibit A, as the Restricted Note Legend (or as set forth in Exhibit B, in the case of Common Stock issued upon conversion of the Notes), unless such Restricted Security has been sold pursuant to a registration statement that has been declared effective under the Securities Act (and which continues to be effective at the time of such transfer) or sold pursuant to Rule 144 under the Securities Act or any similar provision then in force, or unless otherwise agreed by the Company in writing as set forth above, with written notice thereof to the Trustee.

In connection with any transfer of the Notes prior to the date one year after the last date of original issuance of the Notes, the holder must complete and deliver the form of assignment set forth on the certificate representing the Note, with the appropriate box checked, to the Trustee (or any successor Trustee, as applicable). If the proposed transfer is pursuant to clause 1(D) of the Registered Note Legend, the holder must, prior to such transfer, furnish to the Trustee (or any successor Trustee, as applicable), such certifications, legal opinions or other information as the Company may reasonably require to confirm that such transfer is being made pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act. The Restricted Note Legend will be removed from a certificate representing a Note upon the earlier of the transfer of the Note evidenced thereby pursuant to clause 1(B) of the Restricted Note Legend or the expiration of one year from the last date of original issuance of the Notes.

Any Notes that are Restricted Securities and as to which such restrictions on transfer shall have expired in accordance with their terms or as to conditions for removal of the Restricted Note Legend set forth therein have been satisfied may, upon surrender of such Notes for exchange to the Registrar in accordance with the provisions of this Section 2.08, be exchanged for a new Note or Notes, of like tenor and aggregate principal amount, which shall not bear the restrictive legend required by this Section 2.08(c). If such Restricted Security surrendered for exchange is represented by a Global Note bearing the Restricted Note Legend, the principal amount of the legended Global Notes shall be reduced by the appropriate principal amount and the principal amount of a Global Note without a Restricted Note Legend shall be increased by an equal principal amount. If a Global Note without the Restricted Note Legend is not then outstanding, the Company shall execute and the Trustee shall authenticate and deliver an unlegended Global Note to the Depositary.

(d) Any Restricted Securities, prior to the expiration of a one year period after the last date of original issuance of the Notes, purchased or owned by the Company or any Affiliate thereof may not be resold by the Company or such Affiliate unless registered under the Securities Act or resold pursuant to an exemption from the registration requirements of the Securities Act in a transaction which results in such Notes or Common Stock, as the case may be, no longer being “restricted securities” (as defined under Rule 144).

(e) The Trustee shall have no responsibility or obligation to any Agent Members or any other Person with respect to the accuracy of the books or records, or the acts or omissions, of the Depositary or its nominee or of any participant or member thereof, with respect to any ownership interest in the Notes or with respect to the delivery to any Agent Member or other Person (other than the Depositary) of any notice or the payment of any amount, under or

- 19 -

with respect to such Notes. All notices and communications to be given to the holders of Notes and all payments to be made to holders of Notes under the Notes shall be given or made only to or upon the order of the registered holders of Notes (which shall be the Depositary or its nominee in the case of a Global Note). The rights of beneficial owners in any Global Notes shall be exercised only through the Depositary subject to the customary procedures of the Depositary. The Trustee may rely and shall be fully protected in relying upon information furnished by the Depositary with respect to its Agent Members.

The Trustee shall have no obligation or duty to monitor, determine or inquire as to compliance with any restrictions on transfer imposed under this Indenture or under applicable law with respect to any transfer of any interest in any Notes (including any transfers between or among Agent Members) other than to require delivery of such certificates and other documentation or evidence as are expressly required by, and to do so if and when expressly required by, the terms of this Indenture, and to examine the same to determine substantial compliance as to form with the express requirements hereof.

SECTION 2.09.  Replacement Notes . If a mutilated Note is surrendered to the Registrar or if the Noteholder of a Note claims that the Note has been lost, destroyed or wrongfully taken, the Company shall issue and the Trustee shall authenticate a replacement Note if the requirements of Section 8-405 of the Uniform Commercial Code are met, such that the Noteholder (i) satisfies the Company or the Trustee within a reasonable time after he has notice of such loss, destruction or wrongful taking and the Registrar does not register a transfer prior to receiving such notification, (ii) makes such request to the Company or the Trustee prior to the Note being acquired by a protected purchaser as defined in Section 8-303 of the Uniform Commercial Code (a “ protected purchaser ”) and (iii) satisfies any other reasonable requirements of the Trustee. If required by the Trustee or the Company, such Noteholder shall furnish an indemnity bond sufficient in the judgment of the Trustee to protect the Company, the Trustee, the Paying Agent and the Registrar from any loss, expense, claim or liability that any of them may suffer if a Note is replaced and subsequently presented or claimed for payment. The Company and the Trustee may charge the Noteholder for their expenses in replacing a Note. In case any Notes which has matured or is about to mature or has been properly tendered for repurchase on a Fundamental Change Repurchase Date (and not withdrawn), or is to be converted into Common Stock, shall become mutilated or be destroyed, lost or stolen, the Company may, instead of issuing a substitute Notes, pay or authorize the payment of or convert or authorize the conversion of the same (without surrender thereof except in the case of a mutilated Notes), as the case may be, if the applicant for such payment or conversion shall furnish to the Company, to the Trustee and, if applicable, to such authenticating agent such security or indemnity as may be required by them to save each of them harmless for any loss, liability, cost or expense caused by or in connection with such substitution, and, in every case of destruction, loss or theft, the applicant shall also furnish to the Company, the Trustee and, if applicable, any Paying Agent or Conversion Agent evidence to their satisfaction of the destruction, loss or theft of such Notes and of the ownership thereof.

Every replacement Note is an additional obligation of the Company.

- 20 -

The provisions of this Section 2.09 are exclusive and shall preclude (to the extent lawful) all other rights and remedies with respect to the replacement or payment of mutilated, lost, destroyed or wrongfully taken Notes.

SECTION 2.10.  Outstanding Notes . Notes outstanding at any time are all Notes authenticated by the Trustee except for those canceled by it, those delivered to it for cancellation and those described in this Section as not outstanding. A Note does not cease to be outstanding because the Company or an Affiliate of the Company holds the Note.

If a Note is replaced pursuant to Section 2.09, it ceases to be outstanding unless the Trustee and the Company receive proof satisfactory to them that the replaced Note is held by a protected purchaser.

If the Paying Agent segregates and holds in trust, in accordance with this Indenture, on a Fundamental Change Repurchase Date or Maturity Date money sufficient to pay all principal and interest payable on that date with respect to the Notes (or portions thereof) to be repurchased or maturing, as the case may be, and the Paying Agent is not prohibited from paying such money to the Noteholders on that date pursuant to the terms of this Indenture, then on and after that date such Notes (or portions thereof) cease to be outstanding and interest on them ceases to accrue.

SECTION 2.11.  Temporary Notes . Pending the preparation of Notes in certificated form, the Company may execute and the Trustee or an authenticating agent appointed by the Trustee shall, upon the written request of the Company, authenticate and deliver temporary Notes (printed or lithographed). Temporary Notes shall be issuable in any authorized denomination, and substantially in the form of the Notes in certificated form, but with such omissions, insertions and variations as may be appropriate for temporary Notes, all as may be determined by the Company. Every such temporary Notes shall be executed by the Company and authenticated by the Trustee or such authenticating agent upon the same conditions and in substantially the same manner, and with the same effect, as the Notes in certificated form. Without unreasonable delay, the Company will execute and deliver to the Trustee or such authenticating agent Notes in certificated form and thereupon any or all temporary Notes may be surrendered in exchange therefor, at each office or agency maintained by the Company pursuant to Section 4.02 and the Trustee or such authenticating agent shall authenticate and make available for delivery in exchange for such temporary Notes an equal aggregate principal amount of Notes in certificated form. Such exchange shall be made by the Company at its own expense and without any charge therefor. Until so exchanged, the temporary Notes shall in all respects be entitled to the same benefits and subject to the same limitations under this Indenture as Notes in certificated form authenticated and delivered hereunder.

SECTION 2.12.  Cancellation . The Company at any time may deliver Notes to the Trustee for cancellation. The Registrar and the Paying Agent shall forward to the Trustee any Notes surrendered to them for registration of transfer, exchange or payment. The Trustee and no one else shall cancel all Notes surrendered for registration of transfer, exchange, payment or cancellation and dispose of such canceled Notes in accordance with its customary procedures or deliver canceled Notes to the Company. The Company may not issue new Notes to replace Notes it has paid or delivered to the Trustee for cancellation. The Trustee shall not authenticate Notes in place of canceled Notes other than pursuant to the terms of this Indenture.

- 21 -

SECTION 2.13.  Defaulted Interest . Any interest on any Note which is payable, but is not paid when the same becomes due and payable and such nonpayment continues for a period of thirty (30) calendar days, shall forthwith cease to be payable to the Holder on the Regular Record Date, and such defaulted interest and interest (to the extent lawful) on such defaulted interest at the annual rate borne by the Notes (such defaulted interest and interest thereon herein collectively called “ Defaulted Interest ”) shall be paid by the Company at its election, in each case, as provided in clause (a) or (b) below:

(a) The Company may elect to make payment of any Defaulted Interest to the Persons in whose names the Notes (or their respective predecessor Notes) are registered at the close of business on a Special Record Date (as defined below) for the payment of such Defaulted Interest, which shall be fixed in the following manner. The Company shall notify the Trustee in writing of the amount of Defaulted Interest proposed to be paid on each Note and the date (not less than thirty (30) calendar days after such notice) of the proposed payment (the “ Special Interest Payment Date ”), and at the same time the Company shall deposit with the Trustee an amount of money equal to the aggregate amount proposed to be paid in respect of such Defaulted Interest or shall make arrangements satisfactory to the Trustee for such deposit prior to the date of the proposed payment, such money when deposited to be held in trust for the benefit of the Persons entitled to such Defaulted Interest as in this clause provided. Thereupon the Trustee shall fix a record date (the “ Special Record Date ”) for the payment of such Defaulted Interest which shall be not more than fifteen (15) calendar days and not less than ten (10) calendar days prior to the Special Interest Payment Date and not less than ten (10) calendar days after the receipt by the Trustee of the notice of the proposed payment. The Trustee shall promptly notify the Company of such Special Record Date, and in the name and at the expense of the Company, shall promptly cause notice of the proposed payment of such Defaulted Interest and the Special Record Date and Special Interest Payment Date therefor to be given to each Noteholder, not less than ten (10) calendar days prior to such Special Record Date. Notice of the proposed payment of such Defaulted Interest and the Special Record Date and Special Interest Payment Date therefor having been so given, such Defaulted Interest shall be paid on the Special Interest Payment Date to the Persons in whose names the Notes (or their respective predecessor Notes) are registered at the close of business on such Special Record Date and shall no longer be payable pursuant to the following clause (b).

(b) The Company may make payment of any Defaulted Interest in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Notes may be listed, and upon such notice as may be required by such exchange, if, after notice given by the Company to the Trustee of the proposed payment pursuant to this clause, such manner of payment shall be deemed practicable by the Trustee.

(c) Subject to the foregoing provisions of this Section 2.13, each Note delivered under this Indenture upon registration of, transfer of or in exchange for or in lieu of any other Note shall carry the rights to interest accrued and unpaid, and to accrue, which were carried by such other Note.

- 22 -

SECTION 2.14.  CUSIP and ISIN Numbers . The Company in issuing the Notes may use “CUSIP” and “ISIN” numbers (if then generally in use) and, if so, the Trustee shall use “CUSIP” and “ISIN” numbers in notices of repurchase as a convenience to Noteholders; provided , however , that any such notice may state that no representation is made as to the correctness of such numbers either as printed on the Notes or as contained in any notice of a repurchase and that reliance may be placed only on the other identification numbers printed on the Notes, and any such repurchase shall not be affected by any defect in or omission of such numbers. The Company shall promptly notify the Trustee in writing of any changes to the CUSIP and ISIN numbers.

ARTICLE 3

Repurchase of Notes

SECTION 3.01.  Repurchase at Option of Holders Upon a Fundamental Change . (a) If there shall occur a Fundamental Change at any time prior to the Maturity Date, then each Noteholder shall have the right, at such Holder’s option, to require the Company to repurchase all of such Holder’s Notes for cash, or any portion of the principal amount thereof that is equal to $1,000 or an integral multiple thereof, on the date (the “ Fundamental Change Repurchase Date ”) specified by the Company that is not less than twenty (20) Business Days and not more than thirty-five (35) Business Days after the date of the Fundamental Change Company Notice at a repurchase price equal to 100% of the principal amount thereof, together with accrued and unpaid interest thereon to, but excluding, the Fundamental Change Repurchase Date (the “ Fundamental Change Repurchase Price ”). If such Fundamental Change Repurchase Date falls after a Regular Record Date and on or prior to the corresponding Interest Payment Date, the Company shall instead pay the principal amount to the holders of the Notes surrendering the Notes for repurchase pursuant to this Section 3.01, and pay the full amount of accrued and unpaid interest payable on such Interest Payment Date to the holder of record on the close of business on the corresponding Regular Record Date. Repurchases of Notes under this Section 3.01 shall be made, at the option of the holder thereof, upon:

(1) delivery to the Paying Agent by a Holder of a duly completed notice (the “ Fundamental Change Repurchase Notice ”) in the form set forth on the reverse of the Note prior to the close of business on the Business Day immediately preceding the Fundamental Change Repurchase Date (the “ Fundamental Change Repurchase Expiration Time ”); and

(2) delivery or book-entry transfer of the Notes to the Paying Agent at any time after delivery of the Fundamental Change Repurchase Notice (together with all necessary endorsements) at the Corporate Trust Office of the Paying Agent in New York City, such delivery being a condition to receipt by the Holder of the Fundamental Change Repurchase Price therefor; provided that such Fundamental Change Repurchase Price shall be so paid pursuant to this Section 3.01 only if the Note so delivered to the Paying Agent shall conform in all respects to the description thereof in the related Fundamental Change Repurchase Notice.

The Fundamental Change Repurchase Notice shall state:

(i) the certificate numbers, if any, of Notes to be tendered for repurchase, or the appropriate Depositary information if the Notes in respect of which such Fundamental Change Repurchase Notice is being submitted is represented by a Global Note;

- 23 -

(ii) the portion of the principal amount of Note to be repurchased, which must be $1,000 or an integral multiple thereof; and

(iii) that the Note is to be repurchased by the Company pursuant to the applicable provisions of the Notes and this Indenture.

Any purchase by the Company contemplated pursuant to the provisions of this Section 3.01 shall be consummated by the delivery of the consideration to be received by the Holder promptly following the later of the Fundamental Change Repurchase Date and the time of the book-entry transfer or delivery of the Note.

All questions as to the validity, eligibility (including time of receipt) and acceptance of any Notes for repurchase shall be determined by the Company, whose determination shall be final and binding absent manifest error.

Notwithstanding anything herein to the contrary, any Noteholder delivering to the Paying Agent the Fundamental Change Repurchase Notice contemplated by this Section 3.01 shall have the right to withdraw, in whole or in part, such Fundamental Change Repurchase Notice at any time prior to the close of business on the Business Day immediately preceding the Fundamental Change Repurchase Date by delivery of a written notice of withdrawal to the Paying Agent in accordance with Section 3.02 below.

The Paying Agent shall promptly notify the Company of the receipt by it of any Fundamental Change Repurchase Notice or written notice of withdrawal thereof.

(b) On or before the fifth (5 ^th ) calendar day after the occurrence of a Fundamental Change, the Company shall mail or cause to be mailed to all Holders of the Notes, and to beneficial owners as required by applicable law, a notice (the “ Fundamental Change Company Notice ”) of the occurrence of the Fundamental Change and of the repurchase right at the option of the Holders arising as a result thereof. Such mailing shall be by first class mail. The Company shall also deliver a copy of the Fundamental Change Company Notice to the Trustee, the Paying Agent and the Conversion Agent. The Company will also publish a notice containing the information set forth in the Fundamental Change Company Notice in a newspaper of general circulation in New York City or publish such information on the Company’s website or through such other public medium as the Company may use at that time.

Each Fundamental Change Company Notice shall specify:

(i) the events causing the Fundamental Change;

(ii) the date of the Fundamental Change;

(iii) the last date on which a Holder may exercise the repurchase right;

- 24 -

(iv) the Fundamental Change Repurchase Price;

(v) the Fundamental Change Repurchase Date;

(vi) the name and address of the Paying Agent and the Conversion Agent, if applicable;

(vii) that the Notes are eligible to be converted, the applicable Conversion Rate and any adjustments to the applicable Conversion Rate resulting from such Fundamental Change transaction and expected changes in the cash, shares or other property deliverable upon conversion of the Notes as a result of the occurrence of the Fundamental Change, and the method the Company has chosen to satisfy its Conversion Obligation, if any;

(viii) that the Notes with respect to which a Fundamental Change Repurchase Notice has been delivered by a Holder may be converted only if the Holder withdraws the Fundamental Change Repurchase Notice in accordance with the terms of this Indenture;

(ix) that the Holder must exercise the repurchase right by the Fundamental Change Repurchase Expiration Time;

(x) that the Holder shall have the right to withdraw any Notes tendered prior to the Fundamental Change Repurchase Expiration Time;

(xi) state the CUSIP number of the Notes; and

(xii) the procedures that Holders must follow to require the Company to repurchase their Notes.

No failure of the Company to give the foregoing notices and no defect therein shall limit the repurchase rights of Noteholders or affect the validity of the proceedings for the repurchase of the Notes pursuant to this Section 3.01.

(c) Notwithstanding the foregoing, no Notes may be repurchased by the Company at the option of the Holders upon a Fundamental Change if there has occurred and is continuing an Event of Default other than an Event of Default that is cured by the payment of the Fundamental Change Repurchase Price of the Notes.

SECTION 3.02.  Withdrawal of Fundamental Change Repurchase Notice . A Fundamental Change Repurchase Notice may be withdrawn by means of a written notice of withdrawal delivered to the Corporate Trust Office of the Paying Agent in accordance with the Fundamental Change Repurchase Notice at any time prior to the close of business on the Business Day immediately preceding the Fundamental Change Repurchase Date, specifying:

(1) the certificate number, if any, of the Note in respect of which such notice of withdrawal is being submitted, or the appropriate Depositary information if the Note in respect of which such notice of withdrawal is being submitted is represented by a Global Note;

- 25 -

(2) the principal amount of the Note with respect to which such notice of withdrawal is being submitted; and

(3) the principal amount, if any, of such Note that remains subject to the original Fundamental Change Repurchase Notice, which portion must be in principal amounts of $1,000 or multiples of $1,000.

SECTION 3.03.  Deposit of Fundamental Change Repurchase Price . Prior to 10:00 a.m., New York City time, on the Fundamental Change Repurchase Date, the Company shall deposit with the Paying Agent or, if the Company or a Subsidiary of the Company is acting as the Paying Agent, shall segregate and hold in trust as provided in Section 2.06, an amount of cash (in immediately available funds if deposited on the Fundamental Change Repurchase Date), sufficient to pay the aggregate Fundamental Change Repurchase Price of all the Notes or portions thereof that are to be repurchased as of the Fundamental Change Repurchase Date.

If on the Fundamental Change Repurchase Date the Paying Agent holds cash sufficient to pay the Fundamental Change Repurchase Price of the Notes that Holders have elected to require the Company to repurchase in accordance with Section 3.01, then, on the Fundamental Change Repurchase Date, such Notes will cease to be outstanding, interest will cease to accrue and all other rights of the Holders of such Notes will terminate, other than the right to receive the Fundamental Change Repurchase Price upon delivery or book-entry transfer of the Notes. This will be the case whether or not book-entry transfer of the Notes has been made or the Notes have been delivered to the Paying Agent.

SECTION 3.04.  Notes Repurchased in Part . Upon presentation of any Notes repurchased only in part, the Company shall execute and the Trustee shall authenticate and make available for delivery to the Holder thereof, at the expense of the Company, a new Note or Notes, of any authorized denomination, in aggregate principal amount equal to the unrepurchased portion of the Notes presented.

SECTION 3.05.  Covenant to Comply with Securities Laws Upon Repurchase of Notes . The Company will, to the extent applicable, comply with the provisions of Rule 13e-4 and any other tender offer rules under the Exchange Act that may be applicable at the time of the offer to repurchase the Notes, file the related Schedule TO or any other schedule required in connection with any offer by the Company to repurchase the Notes and comply with all other federal and state securities laws in connection with any offer by the Company to repurchase the Notes.

ARTICLE 4

Covenants

SECTION 4.01.  Payment of Notes . The Company shall promptly pay the principal of and interest on the Notes on the dates and in the manner provided in the Notes and in

- 26 -

this Indenture. Principal and interest shall be considered paid on the date due if on such date the Trustee or the Paying Agent holds in accordance with this Indenture money sufficient to pay all principal and interest then due and the Trustee or the Paying Agent, as the case may be, is not prohibited from paying such money to the Noteholders on that date pursuant to the terms of this Indenture.

The Company shall pay interest on overdue principal at the rate specified therefor in the Notes, and it shall pay interest on overdue installments of interest at the same rate to the extent lawful.

SECTION 4.02.  Maintenance of Office or Agency . The Company will maintain an office or agency in the Borough of Manhattan, The City of New York and in Miami, Florida, where the Notes may be surrendered for registration of transfer or exchange or for presentation for payment or for conversion or repurchase and where notices and demands to or upon the Company in respect of the Notes and this Indenture may be served. As of the date of this Indenture, such New York City office is located at the office of the Trustee located at 100 Wall Street, Suite 1600, New York, New York 10005, Attention: Corporate Trust Administration and such Miami, Florida office is located at the office of the Trustee located at 200 South Biscayne Blvd., Suite 1870, Miami, Florida 33131, Attention: Corporate Trust Administration and, at any other time, at such other address as the Trustee may designate from time to time by notice to the Company. The Company will give prompt written notice to the Trustee of the location, and any change in the location, of such office or agency not designated or appointed by the Trustee. If at any time the Company shall fail to maintain any such required office or agency or shall fail to furnish the Trustee with the address thereof, such presentations, surrenders, notices and demands may be made or served at the Corporate Trust Office.

The Company may also from time to time designate co-registrars and one or more offices or agencies where the Notes may be presented or surrendered for any or all such purposes and may from time to time rescind such designations. The Company will give prompt written notice to the Trustee of any such designation or rescission and of any change in the location of any such other office or agency.

So long as the Trustee is the Registrar, the Trustee agrees to mail, or cause to be mailed, the notices set forth in Section 7.08. If co-registrars have been appointed in accordance with this Section, the Trustee shall mail such notices only to the Company and the Noteholders it can identify from its records.

SECTION 4.03.  Reports; 144A Information .

(a) The Company shall deliver to the Trustee, within fifteen (15) calendar days after it would have been required to file them with the SEC, copies of the Company’s annual reports on Form 10-K and of the information, documents and other reports (or copies of such portions of any of the foregoing as the SEC may by rules and regulations prescribe) which the Company is required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act. In the event the Company is at any time no longer subject to the reporting requirements of Section 13 or 15(d) of the Exchange Act, the Company shall continue to provide the Trustee with reports containing substantially the same information as would have been required to be filed

- 27 -

with the SEC had it continued to have been subject to such reporting requirements. In such event, such reports shall be provided at the times the Company would have been required to provide reports had the Company continued to have been subject to such reporting requirements. The Company also shall comply with the other provisions of Section 314(a) of the Trust Indenture Act.

(b) The Company covenants and agrees that it shall, during any period in which it is not subject to Section 13 or 15(d) under the Exchange Act, make available to any holder or beneficial holder of Notes or any Common Stock issued upon conversion thereof which continue to be Restricted Securities and any prospective purchaser of Notes or such Common Stock designated by such holder or beneficial holder, the information required pursuant to Rule 144A(d)(4) under the Securities Act upon the request of any holder or beneficial holder of the Notes or such Common Stock, until such time as such securities are not longer “restricted securities” within the meaning of Rule 144 under the Securities Act.

Delivery of such reports, information and documents to the Trustee is for information purposes only and Trustee’s receipt of such shall not constitute constructive notice of any information contained therein or determinable from information contained therein, including the Company’s compliance with any of its covenants hereunder (as to which the Trustee is entitled to rely exclusively on Officers’ Certificates). The Trustee is under no duty to examine such reports, information or documents to ensure compliance with the provisions of this Indenture or to ascertain the correctness or otherwise of the information or the statements contained therein. The Trustee is entitled to assume such compliance and correctness unless a Responsible Officer of the Trustee is informed otherwise.

SECTION 4.04.  Existence . The Company will do or cause to be done all things necessary to preserve and keep in full force and effect its existence and rights (charter and statutory); provided that the Company shall not be required to preserve any such right if the Company shall determine that the preservation thereof is no longer desirable in the conduct of the business of the Company and that the loss thereof is not disadvantageous in any material respect to the holders of Notes.

SECTION 4.05.  Payment of Taxes and Other Claims . The Company will pay or discharge, or cause to be paid or discharged, before the same may become delinquent:

(i) all taxes, assessments and governmental charges levied or imposed upon the Company or any Significan