“Comcast Concentration Percentage” means 15%, or such lesser percentage as the Administrative Agent may in its reasonable credit judgment determine from time to time.

         “DirecTV Concentration Percentage” means (a) at any time that DirecTV’s corporate credit rating or senior debt rating (secured or unsecured) by Moody’s is Ba3 or higher and by S&P is BB or higher, 30%; providedthat, if Borrowers maintain a Fixed Charge Coverage Ratio as reflected on Borrowers’ quarterly financial statements and the related officer’s certificate delivered in accordance with the respective provisions of Section 10.1(b) and 10.3, on average for any period of 4 consecutive Fiscal Quarters ended on or after June 30, 2005, greater than or equal to 1.25 to 1.00, and no Default or Event of Default exists, then, for the Fiscal Quarter immediately succeeding such 4 consecutive Fiscal Quarter period, so long as DirecTV’s ratings are not less than the levels set forth in this clause (a), 35%; (b) at any time that DirecTV’s corporate credit rating or senior debt rating (secured or unsecured) by Moody’s is lower than Ba3 or by S&P is lower than BB, 20%; or (c) irrespective of DirecTV’s rating, such lesser percentage as the Administrative Agent may in its reasonable credit judgment determine from time to time.

        “Fixed Charge Coverage Ratio” means, for any specified accounting period, the ratio of EBITDA of MasTec’s NAOperations for such period, adjusted, as appropriate, to add back any Non-Cash Non-Recurring Charge Amounts deducted in computing such EBITDA, less the sum of cash income taxes paid and Restricted Payments (other than to the extent permitted by this Agreement), Restricted Distributions (other than to the extent permitted by this Agreement), and Net Capital Expenditures (other than Financed Capex) made, on a consolidated basis by MasTec’s NAOperations during such period, to the sum of their consolidated interest expense for such period and current maturities of long-term Debt as of the date of determination, provided that for any specified accounting period of less than 12 consecutive months, current maturities of long-term Debt as of the date of determination shall be multiplied by a fraction, the numerator of which is the number of months included in such specified accounting period and the denominator of which is 12.

         “Letter of Credit Guarantee Facility” means a subfacility of the Revolving Credit Facility providing for the issuance of (a) Letters of Credit and Letter of Credit Guarantees as described in Article 3 in an aggregate amount of Letter of Credit Obligations at any one time outstanding not to exceed $45,000,000, plus (b) the amount available to be drawn from time to time under the Liberty Letter of Credit, plus (c) the amount available to be drawn from time to time under the Canadian Financing Letter of Credit.

         “Letter of Credit Reserve” means, at any time, the aggregate Letter of Credit Obligations at such time, other than Letter of Credit Obligations that are fully secured by Cash Collateral. For the avoidance of doubt, at any time that the Liberty Letter of Credit is outstanding, the amount of the Letter of Credit Reserve attributable to the Liberty Letter of Credit at such time shall be equal to the lesser of (i) $32,300,000 and (ii) the greatest amount of Letter of Credit Obligations that at any time may be outstanding under the Liberty Letter of Credit in accordance with the terms thereof.

         “Liberty Letter of Credit” means Letter of Credit No. ASL-1 S1295730-120MAT issued by the Issuing Bank for the account of MasTec and for the benefit of Liberty Mutual Insurance Company in an aggregate amount available to be drawn thereunder not to exceed $32,300,000 at any time.

(d) such Account is not owing by an Account Debtor more than 20% (or as to any Approved Account Debtor, 50%) of whose then-existing accounts owing to all the Loan Parties do not meet the requirements set forth in clause (b) above; provided that, any such Account owing by Comcast that is unpaid not more than 60 days after its due date or more than 90 days after the invoice date, net of bad debt allowance, shall be considered an Eligible Account for purposes of (i) Borrowers’ Borrowing Base Certificate that was submitted as of February 28, 2005 (provided that Borrower updates such Borrowing Base Certificate to reflect changes in the Accounts owing by Comcast that have occurred since January 31, 2005, and resubmits such updated Borrowing Base Certificate to the Administrative Agent), and (ii) Borrowers’ Borrowing Base Certificate submitted as of March 25, 2005;

         “Verizon Concentration Limit” means (a) at any time that Verizon’s corporate credit rating or senior debt rating (secured or unsecured) by Moody’s is Baa3 or higher and by S&P BBB- or higher, 30%; if Borrowers maintain a Fixed Charge Coverage Ratio as reflected on Borrowers’ quarterly financial statements and the related officer’s certificate delivered in accordance with the respective provisions of Section 10.1(b) and 10.3, on average for any period of 4 consecutive Fiscal Quarters ended on or after June 30, 2005, greater than or equal to 1.25 to 1.00, and no Default or Event of Default exists, then, for the Fiscal Quarter immediately succeeding such 4 consecutive Fiscal Quarter period, so long as Verizon’s ratings are not less than the levels set forth in this clause (a), 35%; (b) at any time that Verizon’s corporate credit rating or senior debt rating (secured or unsecured) by Moody’s is lower than Baa3 or by S&P is lower than BBB-, 20%; or (c) irrespective of Verizon’s rating, such lesser percentage as the Administrative Agent may in its reasonable credit judgment determine from time to time.

         (a)       Tangible Net Worth. Permit consolidated Tangible Net Worth of MasTec’s NAOperations to be less than the sum set forth below at any time during the period corresponding thereto:

53,500,000.00 plus (ii) an amount equal to 50% of consolidated Net Income (but without deduction for any Net Loss) of MasTec's NAOperations for the period from December 1, 2005, through the date of determination, treated as a single accounting period.

         (b)        Fixed Charge Coverage Ratio. Permit the Fixed Charge Coverage Ratio to be less than the ratio set forth below for the period corresponding thereto:

The 9-calendar month period
ending on December 31, 2004

    (i)        this Amendment duly executed and delivered by the Borrowers, the Required Lenders and the Administrative Agent;

    (ii)        a certificate of the secretary or assistant secretary of each Borrower having attached thereto the articles or certificate of incorporation and bylaws of such Borrower (or containing the certification of such secretary or assistant secretary that no amendment or modification of such articles or certificate of incorporation or bylaws has become effective since the last date on which such documents were last delivered to the Lenders), all corporate or company action, including shareholders’ or members’ approval, if necessary, has been taken by such Borrower and/or its shareholders or members to authorize the execution, delivery and performance of this Amendment and to the further effect that the incumbency certificate most recently delivered to the Lenders remains in effect, unchanged;

    (iii)        a certificate of the chief executive officer of MasTec stating that, to the best of his or her knowledge and based on an examination sufficient to enable him or her to make an informed statement, after giving effect to the Amendment and to the revised Schedules to the Loan Agreement delivered therewith,

    (iv)        such other documents and instruments as any Lender through the Administrative Agent may reasonably request.

        (a)        Authorization of Agreements. Each Borrower has the right and power, and has taken all necessary action to authorize it, to execute, deliver and perform this Amendment and each other agreement contemplated hereby to which it is a party in accordance with their respective terms. This Amendment and each other such agreement contemplated hereby to which it is a party has been duly executed and delivered by the duly authorized officers of such Borrower and each is, or each when executed and delivered in accordance with this Amendment will be, a legal, valid and binding obligation of such Borrower, enforceable in accordance with its terms.

         (b)       Compliance of Agreements with Laws. The execution, delivery and performance of this Amendment in accordance with their respective terms do not and will not, by the passage of time, the giving of notice or otherwise,

        (i)        require any Governmental Approval that has not been obtained or violate any Applicable Law relating to such Borrower or any of its Subsidiaries,

         (ii)        conflict with, result in a breach of or constitute a default under the articles or certificate of incorporation or by-laws or other constituent documents or any shareholders’ or members’ agreement of such Borrower or any of its Subsidiaries, any material provisions of any indenture, agreement or other instrument to which such Borrower, any of its Subsidiaries or any of such Borrower’s or such Subsidiaries’ property may be bound or any Governmental Approval relating to such Borrower or any of its Subsidiaries, or

         (iii)        result in or require the creation or imposition of any Lien upon or with respect to any property now owned or hereafter acquired by such Borrower other than the Security Interest.

         (i)        Borrowers have delivered to Administrative Agent true, correct and complete copies of that certain DirecTV, Inc. 2003 Home Services Provider Agreement dated March 1, 2003, between DirecTV, Inc. and MasTec North America, Inc., as amended by that certain First Amendment to That 2003 Home Services Provider Agreement between MasTec North America, Inc. and DirecTV, Inc. (the “First Amendment”), dated October 6, 2003, and by that certain Second Amendment to That 2003 Home Services Provider Agreement between MasTec North America, Inc. and DirecTV, Inc. (the “Second Amendment”), dated February __, 2004 (as so amended, the “DirecTV Home Services Provider Agreement”).

         (ii)        On March 17, 2005, MasTec North America, Inc. delivered a notice to DirecTV, Inc. in the form attached to this Amendment as Exhibit A.

         (iii)        Other than the DirecTV Home Services Provider Agreement, MasTec North America, Inc. is not a party to any other agreement with DirecTV, Inc.

         (a)       Such Borrower shall cause MasTec North America, Inc. to deliver to the Administrative Agent, within ninety (90) days of the date this Amendment becomes effective, a copy of a fully executed and effective new agreement (the “New DirecTV Agreement”) between MasTec North America, Inc. and DirecTV, Inc. that replaces the Home Services Provider Agreement in its entirety and modifies all of DirecTV, Inc.‘s rights of setoff and recoupment so as to provide (by language acceptable to the Administrative Agent in its reasonable credit judgment) that the New DirectTV Agreement shall be subject and subordinate to any security interest granted by MasTec North America, Inc. in the accounts receivable arising under the New DirectTV Agreement to Fleet Capital Corporation, as administrative agent for the Lenders under MasTec North America, Inc.‘s Revolving Credit and Security Agreement, as may be amended from time to time; and

         (b)       No such Borrower shall (i) enter into any agreement with DirecTV, Inc. other than the New DirecTV Agreement, (ii) modify or amend the Home Services Provider Agreement other than to replace it with the New DirecTV Agreement, or (iii) after the date on which MasTec North America, Inc. delivers to the Administrative Agent a copy of the New DirecTV Agreement, modify or amend the New DirecTV Agreement unless Borrowers shall have delivered written notice of such modification or amendment to the Administrative Agent no fewer than three (3) Business Days prior to the effective date of such modification or amendment. Each Borrower acknowledges and agrees that the Administrative Agent is authorized to establish Additional Reserves with respect to such matters and in such amounts as the Administrative Agent may determine in the exercise of its reasonable credit judgment and that the Administrative Agent may do so in response to any modification or amendment of the New DirecTV Agreement. Nothing in the foregoing shall limit or restrict in any way the right of the Administrative Agent to establish, change and otherwise employ any other Additional Reserve or any other reserve from time to time in the exercise of its reasonable credit judgment, or to exercise any other right or remedy available to the Administrative Agent under the Loan Agreement or otherwise upon the occurrence of any Default or any Event of Default.