Exhibit 10.4

June 1, 2009

MasTec, Inc. and the other

Borrowers referred to below

800 Douglas Road, North Tower, 12th Floor

Coral Gables, Florida 33134

Attention: Chief Executive Officer

Ladies and Gentlemen:

We refer to the Second Amended and Restated Loan and Security Agreement dated
July 29, 2008 (as at any time amended, restated, modified or supplemented, the
“Loan Agreement”), by and among MasTec, Inc., a Florida corporation (“MasTec”),
certain of the Subsidiaries of MasTec which are identified on the signature
pages hereto (together with MasTec, collectively, “Borrowers”), the financial
institutions party thereto from time to time (the “Lenders”) and Bank of
America, N.A., as administrative agent for the Lenders (the “Agent”). All
capitalized terms used in this consent and letter amendment, unless otherwise
defined herein, shall have the meanings ascribed to such terms in the Loan
Agreement, as amended hereby.

Pursuant to that certain letter amendment dated December 16, 2008 (the “Wanzek
Letter Amendment”), the Agent and the Lenders, among other things, acknowledged
and consented to the acquisition by MasTec North America, Inc., a Florida
corporation (“MasTec North America”), of all of the issued and outstanding
capital stock of Wanzek Construction, Inc., a North Dakota corporation
(“Wanzek”) (such transaction is herein referred to as the “Wanzek Acquisition”).

Pursuant to the terms of that certain Stock Purchase Agreement dated as of
October 4, 2008, as amended by that certain First Amendment to Stock Purchase
Agreement dated as of December 2, 2008, and that certain Second Amendment to
Stock Purchase Agreement dated as of December 13, 2008 (the “Purchase
Agreement”), among MasTec North America, Wanzek, Jon L. Wanzek, in his capacity
as sellers’ representative (“Sellers’ Representative”), and the other parties
thereto defined as “Sellers”, as a portion of the Purchase Price (as defined
under the Purchase Agreement) for the Wanzek Acquisition, MasTec North America
made and delivered (i) a Negotiable Subordinated Convertible Note dated
December 16, 2008, in the original principal amount of $47,500,000, payable to
the order of Sellers’ Representative, and (ii) a Negotiable Subordinated
Convertible Note dated December 16, 2008, in the original principal amount of
$7,500,000, payable to the order of the Wanzek Family Foundation, a Minnesota
nonprofit corporation (the “Wanzek Family Foundation”) (collectively, the
“Convertible Notes”).

Borrowers have advised the Agent and the Lenders that MasTec intends to
refinance the Convertible Notes with the proceeds of a proposed public issuance
of new convertible notes in the original principal amount of $100,000,000,
pursuant to an indenture among MasTec, as issuer of the new convertible notes,
certain of MasTec’s Subsidiaries, as guarantors of the new convertible notes,
and the trustee named therein (such refinancing transaction is referred to
herein as the “Proposed Convertible Notes Refinancing”); provided that, the
original principal amount set forth above may be increased by an amount of up to
$25,000,000 to reflect the oversubscription (if any) of the new convertible
notes issued under the new convertible notes indenture.

Pursuant to Section 10.2.3 of the Loan Agreement, Borrowers may not create,
incur, assume, guarantee or suffer to exist any Debt, except for, among other
exceptions, Refinancing Debt so long as each of the Refinancing Conditions is
met. Borrowers

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acknowledge that because the Debt under the proposed new convertible notes is in
an aggregate principal amount exceeding the aggregate principal amount of the
Debt under the Convertible Notes, the Debt under the new convertible notes would
not satisfy clause (i) of the definition of “Refinancing Conditions” and
therefore would not be permitted as Refinancing Debt pursuant to Section 10.2.3
of the Loan Agreement.

Furthermore, pursuant to Section 10.2.6 of the Loan Agreement and the
subordination provisions contained in the Convertible Notes, Borrowers are
prohibited from prepaying or redeeming the Convertible Notes prior to the
maturity date thereof.

Notwithstanding the fact that the Debt under the proposed new convertible notes
does not constitute Refinancing Debt permitted under the Loan Agreement and that
Borrowers are restricted from prepaying the Convertible Notes, Borrowers have
requested that the Agent and the Lenders consent to the Proposed Convertible
Notes Refinancing and the incurrence of Debt by Borrowers under the new
convertible notes.

The Agent and the Lenders are willing to acknowledge and consent to the Proposed
Convertible Notes Refinancing and the incurrence of Debt by Borrowers under the
new convertible notes, on the terms and conditions set forth herein.

The parties also desire to amend the Loan Agreement, subject to the terms and
conditions set forth herein.

NOW, THEREFORE, for the sum of TEN DOLLARS ($10.00) in hand paid and other good
and valuable consideration, the receipt and sufficiency of which are hereby
severally acknowledged, the parties hereto, intending to be legally bound
hereby, agree as follows:

1. Acknowledgment of and Consent to the Proposed Convertible Notes Refinancing
and the New Convertible Notes. At the request of Borrowers, the Agent and the
Lenders hereby acknowledge and consent to the Proposed Convertible Notes
Refinancing by MasTec and the incurrence of Debt by Borrowers under the New
Convertible Notes, and the guaranty by MasTec’s other Subsidiaries thereof, so
long as each of the following conditions has been satisfied, each in form and
substance satisfactory to the Agent, on or before June 30, 2009:

(i) No Default or Event of Default exists at the time of, or will exist
immediately after giving effect to, the Proposed Convertible Notes Refinancing;

(ii) Each Borrower shall delivers to the Agent a duly executed and original
counterpart of this consent and letter amendment;

(iii) The Agent receives evidence that MasTec has paid to the Sellers’
Representative and the Wanzek Family Foundation an amount sufficient to fully
repay the Convertible Notes, including, without limitation, all principal,
interest, fees and other amounts owing in connection therewith (the “Convertible
Notes Repayment Amount”);

(iv) MasTec certifies to the Agent in writing that the Convertible Notes
Repayment Amount is sufficient to fully repay the Convertible Note and that upon
payment of such amount, the Convertible Notes will be cancelled and of no
further force and effect;

(v) The Agent receives a true, correct and complete copy of the executed New
Convertible Notes Indenture;

 

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(vi) MasTec certifies to the Agent in writing that the Proposed Convertible
Notes Refinancing and the issuance of the New Convertible Notes in connection
therewith are permitted under and do not violate the provisions of the Indenture
or cause to exist a default thereunder;

(vii) The Agent receives evidence that the final terms of the Proposed
Convertible Notes Refinancing contained in the New Convertible Notes Indenture
and New Convertible Notes with respect to the restrictions on and priorities of
“Indebtedness” and “Liens” are effective to permit the Loan Agreement, the
Obligations thereunder, and the Liens securing the same (and without limiting
the generality of the foregoing, any restriction on the principal amount of
indebtedness of the “Credit Facility” (or the equivalent term defined in the New
Convertible Notes Indenture) shall not be less than $260,000,000, and the New
Convertible Notes shall at all times remain unsecured);

(viii) Agent receives on the date of this consent and letter amendment full
payment of the fees described in Section 4 below; and

(ix) Each Borrower delivers to the Agent such other agreements as the Agent may
request in connection herewith.

2. Amendments to Loan Agreement. The Loan Agreement is hereby amended as
follows:

(a) By adding the following new definitions of “New Convertible Notes” and “New
Convertible Notes Indenture” to Section 1.1 of the Loan Agreement, in proper
alphabetical sequence:

New Convertible Notes—MasTec’s Senior Convertible Notes having a maturity of not
sooner than five (5) years from the issuance date thereof in the original
principal amount of $100,000,000, issued pursuant to the New Convertible Notes
Indenture, on or before June 30, 2009, on an unsecured basis and otherwise on
terms satisfactory to Agent and Lenders; provided, that, the original principal
amount set forth above may be increased by an amount of up to $25,000,000
reflecting an oversubscription of the New Convertible Notes issued under the New
Convertible Notes Indenture.

New Convertible Notes Indenture—the Indenture among MasTec, its Subsidiaries and
the trustee named thereunder, as Trustee, governing the New Convertible Notes.

(b) By deleting subclause (i) of the definition of “Refinancing Conditions”
contained in Section 1.1 of the Loan Agreement in its entirety, and by
substituting in lieu thereof the following new subclause (i):

(i) the Refinancing Debt is in an aggregate principal amount that does not
exceed the aggregate principal amount of the Debt being extended, renewed or
refinanced (or in the case of each of (A) the Indenture and Senior Notes, and
(B) the New Convertible Notes Indenture and the New Convertible Notes, the
original principal amount thereof),

 

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(c) By deleting subclause (z) of Section 2.1.3 of the Loan Agreement in its
entirety, and by substituting in lieu thereof the following new subclause (z):

(z) to defease, redeem or refinance either the Senior Notes or the New
Convertible Notes.

(d) By deleting Section 3.2.1 of the Loan Agreement in its entirety, and by
substituting in lieu thereof the following new Section 3.2.1:

3.2.1. Unused Line Fee. Borrowers shall pay to Agent for the Pro Rata benefit of
Lenders a fee equal to (i) 0.750% per annum of the amount by which the Average
Revolver Loan Balance for any month (or portion thereof that the Commitments are
in effect) is less than or equal to 50% of the aggregate amount of the Revolver
Commitments; provided that if the Average Revolver Loan Balance for the
immediately preceding Fiscal Quarter (or portion thereof) is greater than 50% of
the aggregate amount of the Revolver Commitments, then such fee shall be
0.500% per annum of the amount by which the Average Revolver Loan Balance for
such month (or portion thereof) is less than the aggregate amount of the
Revolver Commitments, in each case such fee to be paid on the first day of the
following month, provided that, if the Commitments are terminated on a day other
than the first day of a month, then any such fee payable for the month in which
termination occurs shall be paid on the effective date of such termination.

(e) By deleting Section 10.1.13 of the Loan Agreement in its entirety, and by
substituting in lieu thereof the following new Section 10.1.13:

10.1.13. Compliance with Indenture and New Convertible Notes Indenture. Comply
with the terms and provisions of (a) the Indenture and the Senior Notes, and
(b) the New Convertible Notes Indenture and the New Convertible Notes.

(f) By deleting subclause (ii) of Section 10.2.3 of the Loan Agreement in its
entirety, and by substituting in lieu thereof the following new subclause (ii):

(ii) each of the Senior Notes and the New Convertible Notes;

(g) By deleting the last sentence at the end of Section 10.2.6 of the Loan
Agreement.

(h) By deleting Section 10.2.24 of the Loan Agreement in its entirety, and by
substituting in lieu thereof the following new Section 10.2.24:

10.2.24. Amendments to Other Agreements. Amend the interest rate or principal
amount or schedule of payments of principal and interest with respect to any
Debt (other than the Obligations), or any dividend rate or redemption schedule
applicable to any preferred stock of an Obligor, other than to reduce the
interest or dividend rate or to extend any such schedule of payments or
redemption schedule, or amend or cause or permit to be amended in any material
respect or in any respect that may be adverse to the interests of Agent or
Lenders (i) the Indenture or any other agreement at any time governing or
evidencing Subordinated Debt, (ii) the New Convertible Notes Indenture or any
other agreement at any time

 

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governing or evidencing the New Convertible Notes, or (iii) the general
indemnity agreement between any Obligor and any surety that has issued any
outstanding surety bonds for the account of such Obligor or any related
intercreditor agreement.

(i) By deleting Section 12.1.6 of the Loan Agreement in its entirety, and by
substituting in lieu thereof the following new Section 12.1.6:

12.1.6 Other Defaults. There shall occur any default or event of default on the
part of any Obligor or any Subsidiary under (i) the Indenture, (ii) the New
Convertible Notes Indenture, or (iii) under any other agreement, document or
instrument to which such Obligor or such Subsidiary is a party or by which such
Obligor or such Subsidiary or any of their respective Properties is bound,
creating or relating to any Debt (other than the Obligations) in excess of
$2,500,000, in each case if the payment or maturity of such Debt may be
accelerated in consequence of such default or event of default or demand for
payment of such Debt may be made.

3. Additional Inducements. The consents, amendments and acknowledgments herein
are limited as written and do not constitute consents, amendments,
acknowledgments, waivers or releases by the Agent or any Lender of any provision
of the Loan Agreement or any right of the Agent or any Lender thereunder, except
as expressly set forth herein. This consent and letter amendment shall be part
of the Loan Agreement and a breach of any representation, warranty or covenant
herein shall constitute an Event of Default. Nothing herein shall be construed
to be an admission by Borrowers that the Agent’s and the Lenders’ consent or
acknowledgment is required with respect to any future refinancing of Debt.

4. Consent Fees; Expenses of Agent. In consideration of Agent’s and Lenders’
willingness to enter into this Amendment, the Borrowers hereby jointly and
severally agree to pay to Agent, for the Pro Rata benefit of the Lenders that
are signatories to this consent and letter amendment, a nonrefundable consent
fee in the amount of $262,500 in immediately available funds on the date hereof
which shall be fully earned on such date. Additionally, to induce Agent and
Lenders to enter into this consent and letter amendment and grant the
accommodations set forth herein, Borrowers hereby jointly and severally agree to
pay, on the date hereof any other fee required by Agent individually, and on
demand, all costs and expenses incurred by Agent in connection with the
preparation, negotiation and execution of this consent and letter amendment and
any other Loan Documents executed pursuant hereto and any and all amendments,
modifications, and supplements thereto, including, without limitation, the costs
and fees of Agent’s legal counsel and any taxes or expenses associated with or
incurred in connection with any instrument or agreement referred to herein or
contemplated hereby.

5. No Novation, etc. The parties hereto acknowledge and agree that, except as
set forth herein, nothing in this consent and letter amendment shall be deemed
to amend or modify any provision of the Loan Agreement or any of the other Loan
Documents, each of which shall remain in full force and effect, and the Agent’s
and Lenders’ willingness to consent to the Proposed Convertible Notes
Refinancing, and the incurrence of Debt by Borrowers under the New Convertible
Notes, in each case, as set forth herein, shall not extend to, or be deemed a
consent, to any other refinancing, issuance or other transactions other than in
accordance with the terms of the Loan Agreement. This consent and letter
amendment is not intended to be, nor shall it be construed to create, a novation
or accord and satisfaction, and the Loan Agreement as herein modified shall
continue in full force and effect.

6. Acknowledgements and Stipulations; Representation and Warranties. By its
signature below, each Borrower (a) acknowledges and stipulates that (i) the Loan
Agreement and the other Loan Documents executed by such Borrower are legal,
valid and binding obligations of such Borrower that are enforceable against such
Borrower in accordance with the terms thereof,

 

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(ii) all of the Obligations of such Borrower are owing and payable without
defense, offset or counterclaim (and to the extent there exists any such
defense, offset or counterclaim on the date hereof, the same is hereby waived by
each Borrower), (iii) the security interests and liens granted by such Borrower
in favor of the Agent are duly perfected, first priority security interests and
liens (except with respect to those Permitted Liens that are permitted to have
priority pursuant to the Loan Documents), and (iv) the Loan Agreement and each
amendment to the Loan Agreement heretofore entered into by the any or all of the
Borrowers and any actions taken under the Loan Agreement as thereby amended are
hereby ratified and approved by such Borrower; and (b) represents and warrants
to the Agent and the Lenders, to induce the Agent and the Lenders to enter into
this consent and letter amendment, that (i) the execution, delivery and
performance of this consent and letter amendment has been duly authorized by all
requisite corporate or limited liability company action on the part of such
Borrower, (ii) all of the representations and warranties made by such Borrower
in the Loan Agreement and the other Loan Documents are true and correct on and
as of the date hereof, except to the extent that any such representation or
warranty is stated to relate to an earlier date, in which case such
representation or warranty shall be true and correct on and as of such earlier
date, and (iii) to the best of such Borrower’s knowledge, there exists no claim
or cause of action of any kind or nature, whether absolute or contingent,
disputed or undisputed, at law or in equity, that such Borrower has or has ever
had against the Agent or any Lender arising under or in connection with any of
the Loan Documents (and to the extent there exists any such claim or cause of
action on the date hereof, the same is hereby waived by such Borrower).

7. Waiver of Jury Trial. To the fullest extent permitted by Applicable Law, the
parties hereto each hereby waives the right to trial by jury in any action,
suit, counterclaim or proceeding arising out of or related to this consent and
letter amendment.

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This consent and letter amendment shall be governed by and construed in
accordance with the internal laws of the State of Georgia and shall be binding
upon and inure to the benefit of the parties hereto and their respective
successors and assigns. This consent and letter amendment may be executed in any
number of counterparts and by different parties to this consent and letter
amendment on separate counterparts, each of which, when so executed, shall be
deemed an original, but all such counterparts shall constitute one and the same
amendment. Any signature page counterpart delivered by a party by facsimile
transmission shall be deemed to be an original signature page counterpart
hereto.

 

 

Very truly yours, BANK OF AMERICA, N.A., as Agent and a Lender By:  

/s/ Dennis S. Losin

Name:  

Dennis S. Losin

Title:  

Senior Vice President

[Signatures continue on following page.]

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GENERAL ELECTRIC CAPITAL CORPORATION, as a Lender By:  

/s/ Brian Miner

Name:   Brian Miner Title:   Duly Authorized Signatory

[Signatures continue on following page.]

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PNC BANK, NATIONAL ASSOCIATION, as a Lender By:  

/s/ Alex M. Council, IV

Name:   Alex M. Council Title:   Vice President

[Signatures continue on following page.]

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SIEMENS FINANCIAL SERVICES, INC., as a Lender By:  

/s/ Sharon Prusakowski

Name:   Sharon Prusakowski Title:   Vice President By:  

/s/ Anthony Casciano

Name:   Anthony Casciano Title:   Vice President

[Signatures continue on following page.]

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BORROWERS: MASTEC, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President

MASTEC CONTRACTING COMPANY, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President

MASTEC SERVICES COMPANY, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President

MASTEC NORTH AMERICA, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President

CHURCH & TOWER, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President

POWER PARTNERS MASTEC, LLC By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:  

Chief Financial Officer and

Executive Vice President of member, Mastec North America, Inc.

[Signatures continue on following page.]

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GLOBETEC CONSTRUCTION, LLC By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Chief Vice President and Executive Vice
President of member, Mastec North America, Inc. THREE PHASE LINE CONSTRUCTION,
INC. By:  

/s/ Peter Johnson

Name:   Peter Johnson Title:   President PUMPCO, INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Vice President NSORO MASTEC, LLC By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Vice President WANZEK CONSTRUCTION, INC. By:
 

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Vice President

[Signatures continue on following page.]

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GUARANTORS: PHASECOM SYSTEMS INC. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Executive Vice President and Chief Executive
Officer INTEGRAL POWER & TELECOMMUNICATIONS CORPORATION, LTD. By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Chief Financial Officer and Executive Vice
President MASTEC NORTH AMERICA AC, LLC By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Chief Financial Officer and Executive Vice
President of member, Mastec North America, Inc. THREE PHASE ACQUISITION CORP.
By:  

/s/ C. Robert Campbell

Name:   C. Robert Campbell Title:   Vice President

Letter Agreement (Wanzek - New Convertible Note)