SECOND AMENDMENT TO UNDERWRITING, CONTINUING INDEMNITY AND SECURITY AGREEMENT

SECOND AMENDMENT TO UNDERWRITING, CONTINUING INDEMNITY AND
SECURITY AGREEMENT

     THIS SECOND AMENDMENT TO UNDERWRITING, CONTINUING INDEMNITY AND SECURITY AGREEMENT (this “Second Amendment”) made as of the 9th day of January, 2008, by and among QUANTA SERVICES, INC., a Delaware corporation, and certain of its Affiliates and Subsidiaries identified on Exhibit A to this Second Amendment (individually and collectively, in their capacity as a named principal under any Bond, “Principal” and individually and collectively “Indemnitors”); FEDERAL INSURANCE COMPANY, an Indiana corporation, AMERICAN HOME ASSURANCE COMPANY, NATIONAL UNION FIRE INSURANCE COMPANY OF PITTSBURGH, PA., and THE INSURANCE COMPANY OF THE STATE OF PENNSYLVANIA (individually and collectively “Surety”).

WITNESSETH:

     WHEREAS, Surety and certain Indemnitors entered into that certain Underwriting, Continuing Indemnity and Security Agreement dated March 14, 2005 (the “Original Agreement”), as amended and modified by that certain Joinder Agreement and Amendment to Underwriting, Continuing Indemnity and Security Agreement dated November 28, 2006 (the “Joinder Agreement” and, collectively with the Original Agreement, the “Agreement”); and

     WHEREAS, the terms of the Agreement are further amended and modified as set forth in this Second Amendment; and

     WHEREAS, the parties desire to add certain additional Domestic Subsidiaries of Quanta Services, Inc. as Principals and Indemnitors under the Agreement, as amended by this Second Amendment; and

     WHEREAS, Sunesys, LLC, a Delaware limited liability company and a Domestic Subsidiary, is subject to regulation by certain governmental authorities, and the pledge of any assets by Sunesys, LLC would be prohibited or require the consent or approval of certain governmental authorities, and as of the date hereof such requisite consents or approvals are being sought but have not yet been obtained;

     NOW, THEREFORE, in consideration of the foregoing premises, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

     1.  Definitions .

          (a) All capitalized terms used in this Second Amendment (including the recitals hereto) will have the respective meanings assigned thereto in the Agreement, unless otherwise specifically defined in this Second Amendment.

          (b) The definition of “Bonded Contract” in the Agreement is hereby modified to insert “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii”; provided, however, that:

               (i) notwithstanding the foregoing, the definition of “Collateral” in the Agreement and Section 6 of the Agreement, no such Bonded Contract of Sunesys, LLC, nor any rights relating thereto, shall constitute or be included in the Collateral under the Agreement, as amended by this Second Amendment; and

               (ii) notwithstanding the foregoing, the definition of “Bonded Contract” shall be deemed not to be so modified for purposes of the definition of “Licensed Property” or for purposes of Section 7(j) and Section 10 in the Agreement, as amended by this Second Amendment.

          (c) The definition of “Bonds” in the Agreement is hereby modified to insert “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii”; provided, however, that:

               (i) notwithstanding the foregoing and Section 6 of the Agreement, no rights of Sunesys, LLC relating to any Bond shall constitute or be included in the Collateral under the Agreement, as amended by this Second Amendment; and

               (ii) notwithstanding the foregoing, the definition of “Bonds” shall be deemed not to be so modified for purposes of the definition of “Licensed Property” in the Agreement, as amended by this Second Amendment.

          (d) Clauses (c) and (f) of the definition of “Event of Default” in the Agreement are hereby modified to insert “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii” wherever such term appears in each such clause.

          (e) The definition of “Retainage” in the Agreement is hereby modified to insert “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii” wherever such term appears in such definition solely for purposes of including such Retainage in the meaning of Bonded Contract Balances as such term is used in the second paragraph of Section 32 of the Agreement; provided, however, that except for purposes of the second paragraph Section 32 of the Agreement, the defined terms “Retainage” and “Bonded Contract Balances” shall not be amended or modified by this Section 1(e) in any respect.

          (f) The definition of “Surety Loss” in the Agreement is hereby modified to insert “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii” wherever such term appears in such definition.

          (g) The definition of “Work” in the Agreement is hereby modified to insert (i) “and/or Sunesys, LLC” immediately after “Island Mechanical, Hawaii” wherever such term appears in such definition and (ii) “and/or Sunesys, LLC’s” immediately after “Island Mechanical, Hawaii’s” where such term appears in such definition.

          (h) Notwithstanding the foregoing provisions of this Section 1 or anything to the contrary in this Second Amendment, Surety acknowledges and agrees that Sunesys, LLC is not a party to the Agreement or this Second Amendment, and that the Indemnitors are not authorized to, do not purport to, and do not, bind Sunesys, LLC (including, without limitation, with respect to the provisions set forth in Sections 6, 22, 28, 29, 32 and 33 of the Agreement) by their execution and delivery of this Second Amendment.

     2.  Sunesys, LLC . Sunesys, LLC, a Delaware limited liability company, is a Domestic Subsidiary. Notwithstanding anything to the contrary contained herein or in the Agreement, neither Sunesys, LLC nor any subsidiary of Sunesys, LLC is or at any time shall be, or be deemed to have been, a Principal (as defined in the Agreement), an Indemnitor (as defined in the Agreement) or a party to this Second Amendment or the Agreement for any purpose, until such time as it may execute a rider pursuant to Section 52 of the Agreement (or an addendum to the Agreement) agreeing to be bound by the Agreement, as amended by this Second Amendment. Sunesys, LLC is endeavoring to obtain the necessary governmental approvals so that it can become a party to the Agreement, as amended by this Second Amendment, and once all requisite approvals have been obtained, the applicable Indemnitor(s) agree to cause Sunesys, LLC to execute a rider or an addendum to be added as Principal (as defined in the Agreement) and Indemnitor (as defined in the Agreement).

     3.  Exhibit A; Releases .

          (a) Exhibit A to the Agreement is hereby deleted in its entirety and replaced with Exhibit A to this Second Amendment.

          (b) Indemnitors have represented to Surety that Total Quality Management Services, LLC, a Delaware limited liability company (“TQMS”), is not an operating entity and has immaterial assets. Based on this representation, Surety (as defined in the Agreement) has agreed to release, and hereby does fully and forever release, TQMS from the Agreement, each other Surety Credit Document and any and all obligations thereunder of any kind and every nature and, without limiting the generality of the foregoing, acknowledges and agrees that, as of the date hereof, TQMS is no longer a Principal (as defined in the Agreement) or Indemnitor (as defined in the Agreement).

          (c) Indemnitors have represented to Surety that VCS Sub, Inc. (formerly known as Environmental Professional Associates, Limited), a California corporation (“VCSS”), is not an operating entity and has immaterial assets. Based on this representation, Surety (as defined in the Agreement) has agreed to release, and hereby does fully and forever release, VCSS from the Agreement, each other Surety Credit Document and any and all obligations thereunder of any kind and every nature and, without limiting the generality of the foregoing, acknowledges and agrees that, as of the date hereof, VCSS is no longer a Principal (as defined in the Agreement) or Indemnitor (as defined in the Agreement).

     4.  Exhibit B . Exhibit B to the Agreement is hereby amended by adding thereto the Permitted Liens set forth on Exhibit B to this Second Amendment.

     5.  Warranties and Covenants of Indemnitors . Each Indemnitor listed as a signatory to this Second Amendment that was not a signatory to the Joinder Agreement (each such Indemnitor being a “New Indemnitor”) represents and warrants to Surety that all of the representations and warranties made by the Indemnitors (as defined in the Agreement) in the Original Agreement (whether made as an Indemnitor (as defined in the Agreement) or as a Principal (as defined in the Agreement)) are true and correct as applicable to such New Indemnitor in all material respects, as of the date hereof (except to the extent such representations and warranties specifically relate to an earlier date). Each New Indemnitor hereby acknowledges, agrees, and confirms that, by its execution of this Second Amendment, the New Indemnitor will be deemed to be a party to the Agreement, as amended by this Second Amendment, and an “Indemnitor” (as defined in the Agreement) and “Principal” (as defined in the Agreement) for all purposes of the Agreement, as amended by this Second Amendment, and shall have all the obligations of an Indemnitor (as defined in the Agreement) and Principal (as defined in the Agreement) thereunder as if it had executed the Agreement. Each New Indemnitor hereby ratifies, as of the date hereof, and agrees to be bound by, all of the terms, provisions, and conditions contained in the Agreement, as amended by this Second Amendment, applicable to such New Indemnitor (whether as an Indemnitor (as defined in the Agreement) or Principal (as defined in the Agreement)). Without limiting the generality of the foregoing terms of this Section 5, each New Indemnitor hereby grants to the Surety a security interest in any and all right, title and interest of such New Indemnitor in and to the Collateral of such New Indemnitor to secure the prompt payment and performance in full when due of any Surety Loss, and the payment and performance of all other obligations and undertakings now or hereafter owing to Surety with respect to the Bonds and/or under the Surety Credit Documents, as same may now or hereafter be modified, replaced, extended or renewed.

     6.  Due Diligence Items Required to be Delivered by New Indemnitors . Each New Indemnitor will deliver to Surety the following, in form and substance reasonably satisfactory to Surety and its counsel:

          (a) Favorable opinions of both outside and in-house counsel to Principal and Indemnitors, with respect to the New Indemnitors, substantially in the form attached to the Original Agreement as Exhibit C thereto, with such modifications thereto as are requested by such counsel and acceptable to Surety and its counsel in their reasonable discretion;

          (b) an officer’s certificate of such New Indemnitor certifying appropriate resolutions authorizing the execution, delivery, and performance of this Second Amendment and performance of the Agreement, as amended by this Second Amendment, certifying that such resolutions have been approved in accordance with such New Indemnitor’s governing documents together with copies of such governing documents, and certifying incumbencies and true signatures of the officers so authorized; and

          (c) evidence of the good standing of such New Indemnitor in the jurisdiction in which such New Indemnitor is formed.

     7.  Power of Attorney . Each New Indemnitor hereby irrevocably constitutes and appoints Quanta Services, Inc. (and all officers, employees, or agents designated by Quanta

Services, Inc.), with full power of substitution, as such New Indemnitor’s true and lawful attorney-in-fact with full irrevocable power and authority in the place and stead of such New Indemnitor and in the name of such New Indemnitor or in its own name, from time to time in Quanta Services, Inc.’s discretion, to take any and all appropriate action and to execute and deliver any and all documents and instruments which may be necessary or desirable to accomplish the purpose of this Second Amendment or the Agreement and to amend, modify or supplement the Agreement or other Surety Credit Documents in any manner. Each New Indemnitor hereby ratifies and agrees to be bound by, to the fullest extent permitted by law, all that Quanta Services, Inc. will lawfully do or cause to be done by virtue hereof.

     8.  Miscellaneous .

          (a) Upon the effectiveness of this Second Amendment, each reference in the Agreement to “this Agreement,” “hereunder” or words of like import shall mean and be a reference to the Agreement, as affected and amended by this Second Amendment. The foregoing is not intended to otherwise affect the definition of “Agreement” or “this Agreement.”

          (b) This Second Amendment shall be governed by and construed in accordance with the internal laws of the State of New York.

          (c) Section headings in this Second Amendment are included herein for convenience of reference only and shall not constitute a part of this Second Amendment for any other purpose.

     9.  Binding Effect . By executing this Second Amendment, each New Indemnitor will be deemed to be an Indemnitor (as defined in the Agreement) under the terms of the Agreement, as amended hereby, as though such New Indemnitor were an original signatory thereto and such New Indemnitor hereby confirms its grant of a security interest in the Collateral to Surety as provided in Section 5 of the Agreement.

     10.  Continuing Effect . Except as specifically set forth in this Second Amendment, the Agreement remains in full force and effect in accordance with its terms.

     11.  Counterparts . This Second Amendment may be executed by the parties independently in any number of counterparts, all of which together will constitute but one and the same instrument which is valid and effective as if all parties had executed the same counterpart. This Second Amendment may be validly executed and delivered by facsimile or other electronic transmission. Notwithstanding the foregoing, the parties are required to deliver original signature pages to each other.

     IN WITNESS WHEREOF, each of the parties has caused this Second Amendment to be executed by its duly authorized officer as of the day and year first above written.

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