FORM OF NEGOTIABLE SUBORDINATED CONVERTIBLE NOTE

Exhibit 4.1 FORM OF NEGOTIABLE SUBORDINATED CONVERTIBLE NOTE THE INDEBTEDNESS EVIDENCED HEREBY IS SUBORDINATED TO THE SENIOR INDEBTEDNESS (AS DEFINED HEREIN), PURSUANT TO THE TERMS AND CONDITIONS CONTAINED HEREIN. THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT TO THE SECURITIES UNDER SUCH ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED OR UNLESS SOLD PURSUANT TO RULE 144 OF SUCH ACT. THE SALE OR OTHER DISPOSITION OF ANY OF THE SECURITIES REPRESENTED BY THIS NOTE IS RESTRICTED BY A CERTAIN STOCK PURCHASE AGREEMENT, AS AMENDED FROM TIME TO TIME, BY AND AMONG THIS COMPANY, MASTEC, INC., WANZEK CONSTRUCTION, INC., TRUST B UNDER THE AMENDED AND RESTATED LIVING TRUST OF LEO WANZEK DATED FEBRUARY 2, 2000, JANET L. WANZEK, WANZEK CONSTRUCTION 2008 IRREVOCABLE TRUST, JON L. WANZEK, AND JON L. WANZEK 2008 TWO-YEAR IRREVOCABLE ANNUITY TRUST. A COPY OF THE STOCK PURCHASE AGREEMENT IS AVAILABLE FOR INSPECTION DURING NORMAL BUSINESS HOURS AT THE PRINCIPAL EXECUTIVE OFFICE OF THIS COMPANY AND WILL BE FURNISHED TO THE RECORD HOLDER OF THIS NOTE WITHOUT CHARGE UPON WRITTEN REQUEST TO THE COMPANY AT ITS PRINCIPAL PLACE OF BUSINESS. NEGOTIABLE SUBORDINATED CONVERTIBLE NOTE

      FOR VALUE RECEIVED, MASTEC NORTH AMERICA, INC. (the "Company" ), hereby promises to pay to the order of                                ( "Holder" ), the principal amount of                                ($                      ) on December       , 2013 (the "Maturity Date" ), and to pay interest on the unpaid principal balance hereof at the rate of eight percent (8%) per annum from the date hereof (the "Issuance Date" ). The principal balance of this Note shall be payable pursuant to Section 1.a . Interest on this Note shall accrue and be payable pursuant to Section 1.b . Capitalized terms used but not defined herein have the respective meanings ascribed thereto in the Stock Purchase Agreement, dated as of October 4, 2008, as subsequently amended, by and among the Company, MasTec, Inc., a Florida corporation (the "Guarantor" ), Wanzek Construction, Inc., a North Dakota corporation, Trust B under the Amended and Restated Living Trust of Leo Wanzek dated February 2, 2000, a North Dakota trust, Janet L. Wanzek, a North Dakota resident, Wanzek Construction 2008 Irrevocable Trust, a North Dakota trust, Jon L. Wanzek, a North Dakota resident ( "Jon" ), Jon L. Wanzek 2008 Two-Year Irrevocable Annuity Trust, a North Dakota trust, and Jon, as Sellers’ Representative.

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     1.  Payments of Principal and Interest . Subject to the provisions of Section 15 hereof:           a.  Payment of Principal . The principal balance of this Note shall be paid to the Holder hereof on the Maturity Date. The Company shall not prematurely pay or prepay any outstanding principal balance to the Holder, except pursuant to Section 3 .           b.  Payment of Interest . Interest on the unpaid principal balance of this Note shall accrue at a rate of eight percent (8%) per annum commencing on the Issuance Date. Interest shall be paid each April ___, August ___, and December ___, commencing April ___, 2009, during the term of this Note.           c.  General Payment Provisions . All payments of principal and interest on this Note shall be made in lawful money of the United States of America by wire transfer of immediately available funds to such account as the Holder may from time to time designate by written notice to the Company in accordance with the provisions of this Note. Whenever any amount expressed to be due by the terms of this Note is due on any day which is not a Business Day, the same shall instead be due on the next succeeding day which is a Business Day and, in the case of any interest payment date which is not the date on which this Note is paid in full, the extension of the due date thereof shall not be taken into account for purposes of determining the amount of interest due on such date.      2.  Conversion of Note . This Note shall be convertible into shares of the Guarantor’s common stock, par value $.10 per share (the "Common Stock" ), on the terms and conditions set forth in this Section 2 .           a.  Certain Defined Terms . For purposes of this Note, the following terms shall have the following meanings:                i.  "Conversion Amount" means the sum of (A) the principal amount of this Note to be converted, plus (B) all accrued and unpaid interest.                ii.  "Conversion Price" means $12 per share of Common Stock.                iii.  "Family Group" means Jon and his spouse, their siblings, parents and descendants (whether natural or adopted) and any trust formed and maintained solely for the benefit of such persons.                iv.  "Minimum Conversion Amount" means a minimum principal amount of $5,500,000.

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               v.  "Transfer Agent" means [Insert].           b.  Conversion Right . At any time or times on or after the Issuance Date, the Holder shall be entitled to convert, any part equal to or in excess of the Minimum Conversion Amount of the outstanding and unpaid principal amount of this Note into fully paid and nonassessable shares of Common Stock at the Conversion Rate (as defined below).           c.  Treatment of Accrued Interest Upon Conversion . Upon any conversion pursuant to subsection b of this Section 2 , the accrued and unpaid interest outstanding on the date of conversion (the "Conversion Date" ) shall be converted into fully paid and nonassessable shares of Common Stock at the Conversion Rate.           d.  Fractional Shares . No fractional shares of Common Stock shall be issued upon any conversion. If a conversion would result in the issuance of a fraction of a share of Common Stock, the number of shares of Common Stock to be issued upon such conversion shall be rounded down to the nearest whole share.           e.  Conversion Rate . The number of shares of Common Stock issuable upon conversion of this Note pursuant to subsection b of this Section 2 shall be determined according to the following formula (the "Conversion Rate" ): Conversion Amount
Conversion Price           f.  Mechanics of Conversion . The conversion of this Note shall be conducted in the following manner:                i.  Holder’s Delivery Requirements . To convert this Note into shares of Common Stock pursuant to subsection b of this Section 2 , the Holder shall (A) transmit by facsimile (or otherwise deliver) a copy of a fully executed notice of conversion in the form attached hereto as Exhibit I (a "Conversion Notice" ) to the Company and (B) surrender to the Company the original Note.                ii.  Conversion . Upon receipt of a Conversion Notice and the original Note by the Company in accordance with Section 2.f.i , the Company shall instruct the Transfer Agent to process such Conversion Notice in accordance with the terms herein. Upon receipt by the Transfer Agent of a copy of the executed Conversion Notice, the Transfer Agent shall, not later than the third Business Day following the date of receipt, issue and surrender to a common carrier for overnight delivery to the Holder, a certificate, issued in the name of the Holder for the number of shares of Common Stock to which the Holder shall be entitled. If less than the principal amount of this Note is submitted for conversion, then the Company shall, as soon as practicable and in no event later than three Business Days after receipt of the Note and at its own expense, issue and deliver to the Holder a new Note for the outstanding principal amount not converted.

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               iii.  Record Holder . As of the Conversion Date, the Holder shall be treated for all purposes as the record holder of the shares of Common Stock to be issued on such date.                iv.  ATermination of Accrued Interest . Upon the Company’s receipt of any Conversion Notice, no further interest shall accrue with respect to the principal amount to be converted pursuant to such notice.           g.  Taxes . The Holder shall pay any and all taxes that may be payable with respect to the issuance and delivery of Common Stock upon the conversion of this Note.           h.  Adjustments to Conversion Price . The Conversion Price will be subject to adjustment from time to time as provided in this Section 2.h .                i.  Adjustment of Conversion Price upon Subdivision or Combination of Common Stock . If the Guarantor at any time subdivides (by any stock split, stock dividend, recapitalization or otherwise) its outstanding shares of Common Stock into a greater number of shares, the Conversion Price in effect immediately prior to such subdivision will be proportionately reduced. If the Guarantor at any time combines (by combination, reverse stock split or otherwise) its outstanding shares of Common Stock into a smaller number of shares, the Conversion Price in effect immediately prior to such combination will be proportionately increased.                ii.  Notices . Immediately upon any adjustment of the Conversion Price, the Company will give written notice thereof to Holder setting forth in reasonable detail, and certifying, the calculation of such adjustment.           i.  Limitation on Beneficial Ownership . The Holder shall not have the right to convert this Note pursuant to Section 2.b to the extent that after giving effect to such conversion the Holder (together with such Person’s affiliates) would beneficially own 10% or more of the outstanding shares of the Common Stock following such conversion. For purposes of this Section 2.i , beneficial ownership shall be calculated in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended. Notwithstanding anything to the contrary contained herein, each Conversion Notice shall constitute a representation by the Holder that, after giving effect to such Conversion Notice, the Holder will not beneficially own (as determined in accordance with this Section&