SecProbe.io

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549-7010
         DIVISION OF
CORPORATION FINANCE

May 17, 2007

Mail Stop 7010

By U.S. Mail and facsimile to (713) 629-7676

Tana L. Pool
Vice President and General Counsel
Quanta Services, Inc.
1360 Post Oak Boulevard, Suite 2100
Houston, Texas 77056

Re:  Quanta Services, Inc.
 Registration Statement on Form S-4
Filed April 20, 2007
 File No. 333-142279
  Quanta Services, Inc., Form 10-K for the period ended 12/31/2006
Filed February 28, 2007
File No. 001-13831
Infrasource Services, Inc. Form 10-K for the period ended 12/31/2006
Filed March 13, 2007
 File No. 001-32164

Dear Ms. Pool:

We have reviewed your filings and have the following comments.  Where
indicated, we think you should re vise your documents in response to these comments.  If
you disagree, we will consider your explanation as to why our comment is inapplicable or
a revision is unnecessary.  Please be as deta iled as necessary in your explanation.  In
some of our comments, we may ask you to provide us with supplemental information so
we may better understand your disclosure.  After reviewing this information, we may
raise additional comments.

Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comments or any other aspect of our review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 2
General

1. Please provide for staff review all materials prepared by the parties’ financial advisors and provided to their respective boa rds, or their representatives.  Provide
the board books and all transcripts, summar ies, and video presentation materials.
We may have further comment based on our review of these materials.

2. Please also provide us with all financia l projections and forecasts that were
prepared by the parties or their advisors and exchanged with the other party to the
transaction.  Please note that any such material exchanged forecasts must be
disclosed in the joint proxy statement/prospectus.

3. Please note that all written soliciting mate rials, including emails or scripts to be
used in soliciting proxies over the te lephone, must be filed under cover of
Schedule 14A.  Please refer to Item  14a-6(b) and (c) and confirm your
understanding.

4. We note that each solicitation will seek discretion to vote on other business that
may come before the meeting or any ad journment, including an adjournment for
the purpose of soliciting additional proxies.  We note disclosure on pages 86 and 89 that the parties contemplate adjourni ng their respective meetings to solicit
additional proxies.  This action must app ear as a separate item for shareholder
approval, as it is not an incidental matte r as contemplated by Exchange Act Rule
14a-4(c)(7).  Refer also to Rule 14a-4(a)(3).

5. A summary term sheet setting forth the pr incipal terms of th e transaction should
precede the Table of Contents of the joint proxy statement/prospectus.  The summary term sheet should concisely desc ribe the most material terms of the
proposed transaction and include cross-re ferences to more detailed discussion
contained in the registration statement.  For further guidance, refer to Item 1001
of Regulation M-A and Section II.F.2.a of Securities Act Release 7760 (January
24, 2000).

6. Please provide updated financial statements and related disclosures, as necessary,
to comply with Article 3-12 of Regulation S-X.

7. Please provide updated consents from your  independent accountants in each
amendment to your registration statement.

Cover Page of Registration Statement

8. We note the disclosure in f ootnote (1) to the fee regist ration table.  Please be
advised that counsel’s lega lity opinion should also cover the preferred stock
purchase rights.

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 3
Summary, page 7

9. Please disclose the outstanding common stock of Quanta before and after the proposed merger, on a fully-diluted basis,  and taking into account Quanta’s
assumption of InfraSource’s equity award plans.  In addition, please disclose the percentage of Quanta’s common stock th at Quanta and InfraSource stockholders
will own following the completion of the merger.  In this regard, we note the disclosure in the first risk factor on page 25.

The Merger, page 7

10. Please disclose the aggregate market value of the consideration to be received in the merger on the last trading day prior to the public announcement, and disclose
that this amount will fluctuate.  In add ition, please disclose the aggregate market
value as of the most recent practicable date.

Opinions of the Financial Advisors, page 9

11. Please revise your disclosure under this he ading to specify the fees payable to
each financial advisor.  Please include disclosure regarding the fee that is
contingent upon completion of the merger.

Selected Historical Financial Data of InfraSource, page 16

12. The periods presented for InfraSource’s predecessor and successor entities during
2003 appear to overlap by several months.  Please revise your introductory paragraph to clarify this matter by disclo sing, if true, that the successor entity had
no operating activity prio r to September 24, 2003.

Comparative Per Share Data, page 20

13. Please delete the statement in the fourth  sentence of the introductory paragraph
that the disclosure in this section is pr ovided for “illustrative purposes.”  Please be
advised that you are responsible for the en tire content of your filing and may not
include language that may be interpreted as a disclaimer of that content.

14. We note that Quanta will issue to Infra source stockholders 1.223 shares of Quanta
common stock for each share of Infrasource common stock.  Please provide equivalent pro forma per share data for Infrasource stock as required by Item 3(f)
of Form S-4, or tell us why you do not think this is applicable.

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 4
Risk Factors, page 23

15. We note the disclosure on page 40 rega rding the potential customer overlap.
Please add a risk factor that descri bes this risk in reasonable detail.

The Merger, page 31
Background of the Merger, page 31

16. Please briefly expand your discussion to disclose the reason(s) the principal
stockholders retained Citigroup in Augus t 2005 to assess strate gic alternatives.

17. Please revise the disclosure regarding the December 8, 2005, meeting of Quanta’s
board of directors to discuss the proposal  made on behalf of InfraSource.  Please
disclose the party that initiated disc ussions and the content of the proposal.

18. Please disclose the number of parties with which InfraSource entered into
confidentiality agreem ents in December 2005.

19. Your discussion under this heading make s no reference to negotiations between
IntraSource and alternative parties after December 2005.  Please revise
throughout your discussion to provide inve stors with a sense of alternative
strategic options and negotiations with pa rties besides Quanta.  In this regard,
please clearly explain the st rategic alternatives contem plated throughout the entire
period from December 2005 through the si gning of the merger agreement and
why those alternatives were not expl ored or completed.  For example, you
indicate that InfraSource’s management met with its financial advisor on November 16, 2006 to discuss various strategic alternatives, but you do not indicate the substance of those discus sions or indicate wh ether you were in
discussions with any other parties.

20. We note the disclosure in the third to last paragraph on page 33 regarding the
negotiation of the letter of in tent.  Please revise your di scussion to clearly disclose
the substance of those negotiations, incl uding the material terms discussed, how
the parties differed in thei r positions, and the outcome of the negotiations.  Please
also comply with this comment with respect to the disclosure regarding the negotiation of the merger agreement.   In  this regard, please clearly explain the
negotiations concerning the exchange ratio.

Recommendation of the Quanta Board of Dir ectors and Its Reasons for the Merger, page
38

21. The disclosure in the bullets points li sts the factors considered, but does not
explain why those factors either were favorable, neutral, or negative.  Please

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 5
revise accordingly.  Please also comply with this comment with respect to the “Other Factors” considered by InfraS ource’s board of directors on page 42.

Opinion of Quanta’s Financial Advisor, page 42

22. Please review the disclosure in this s ection, the section enti tled “Opinion of
InfraSource’s Financial Advisor” begi nning on page 47, and discussion of the
merger agreement beginning on page 61 to remove all disclosure that indicates that the summary in these sections is not  complete.  A summary by its nature is
not complete.  Your language suggests that  the disclosure in your filing does not
include all of the material information regarding the opinions.  For example, we
note the statements in the second sentence of the first paragraph under the heading
“Financial Analysis” on page 44 and in the first sentence of the second paragraph under the heading “General” on page 54.

23. Please remove the last sentence of the s econd paragraph.  In this regard, we note
that stockholders are entitled to rely solely  on the disclosure in your filing.  Please
also comply with this comment with respect to the sec ond paragraph under the
heading “Opinion of InfraSource’s Financial Advisor” on page 47.

24. Please disclose the basis for Credit Suisse’s assumption that the financial
projections provided by the parties were  reasonably prepared.  Also, in an
appropriate place in this disclosure, pleas e indicate whether the respective boards
reviewed, for accuracy and completeness, this financial information and whether
the boards found Credit Suisse’s reliance upon those materials to be reasonable.
Make similar revisions to the discus sion on page 48 of the opinion provided by
Citigroup to InfraSource.

Discounted Cash Flows Analyses, page 45

25. Please revise the disclosure of the disc ounted cash flow analysis performed for
each company to briefly disclose the basis for the selected forward terminal EBITDA multiples and discount rates.  Sim ilarly revise the disclosure of the
discounted cash flow analyses performed by Citigroup to disclose the basis for the
selected WACC range and terminal 2011E EBITDA multiple range.

Selected Company Analysis, page 45

26. Please briefly revise to disclose the criter ia utilized by Credit Suisse in selecting
the three companies evaluated.  Please also disclose whether any companies satisfying these criteria were  nonetheless excluded from the analysis and, if so,
disclose the basis for such exclusion.  Pr ovide similar disclosu re with respect to
the premiums paid and comparable p ublic companies analyses performed by
Citigroup.  With respect to the comparable  public companies analysis of Quanta

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 6
performed by Citigroup, please revise to  indicate whether the peer group of
selected companies is the same as the group selected for its comparable
companies analysis of InfraSource.

Miscellaneous, page 46

27. Revise to disclose the amount of fees Cr edit Suisse received in connection with
acting as an underwriter of InfraSource’s April 2006 and September 2006 secondary offerings.  Please also revise to disclose the fees Credit Suisse will receive in conjunction with the propose d merger, both as an aggregate amount
and the amount that is contingent upon consummation of the proposed merger.
Similarly revise the discussion of fees  payable to Citigroup on pages 54-55.

Interests of InfraSource Directors . . ., page 55

28. Please disclose the amount of each benef it to be received by InfraSource’s
directors and officers.

Certain Material U.S. Federal Income Ta x Consequences of the Merger, page 57

29. Revise this subheading as well as the disc ussion under this heading as well as that
appearing in the Summary on page 12 and in the Table of Contents to clarify that you are discussing all “material,” rather th an “certain” or “certain material” tax
considerations.

30. Please revise the first sentence of the last paragraph of this s ection to remove the
statement that the discussion in this s ection is for “general information only.”

The Merger Agreement, page 61

31. We note the statements in the second  introductory paragr aph regarding the
representations and warranties contained in  the merger agreemen t.  We have the
following comments:
• Please revise to remove any implication that the merger agreement does not constitute disclosure under the federal securities laws.  In this regard,
please delete the fourth and fift h sentences of this paragraph.
• Please be advised that, notwith standing your statements, you are
responsible for considering whether a dditional disclosure may be required
to make the statements included in your proxy statement not misleading.

Comparison of Rights of Quanta’s Stockholde rs and InfraSource’s St ockholders, page 84

32. Please revise the discussion of Quanta’s post-merger capital stock to include the
shares being issued as consideration.

Tana L. Pool
Quanta Services, Inc.
May 17, 2007 Page 7
Unaudited Pro Forma Combined Stat ement of Operations, page F-4

33. Please revise the line titled “income from continuing operations” on your pro
forma statement of operations to clarify, if true, that this is income from
continuing operations before nonrecurring char ges or credits dire ctly attributable
to the transaction.  Refer to Arti cle 11-02(b)(5) of Regulation S-X.

Notes to Unaudited Pro Forma Combined Financial Statements
Note 2(a) – Purchase Price, page F-5

34. We note your discussion of the treatment of InfraSour ce’s stock options in the
first paragraph of Note 2(a) and in Se ction 2.3 of your Agreement and Plan of
Merger.  Please tell us what considera tion you gave to the impact of the stock
options you will issue on InfraSource’s aggregate purchase price.

35. We read that your calculation of the aggr egate purchase price is based upon the
average closing price of Quanta common stock for the five trading days ended
March 20, 2007.  It appears that you public ly announced this merger on March
19, 2007.  Please tell us what consider ation you gave to EITF 99-12 in
determining the measurement date for the market price of Quanta’s stock.

36. Your calculation of the aggregate purchase  price states that it is presented in
thousands, except ratios and per share info rmation.  However, it appears that your
total purchase price and the allocation of that total purchase price to acquired
assets and liabilities may be presented in millions.  Please advise or revise.

37. We note that your preliminary purchase price allocation a ssumes that the book
value of InfraSource’s net tangible assets approximates their fair value based upon your initial evaluations.  Please revise your disclosure  to provide more detail
about the status of these evaluations a nd when you expect to complete them.
Please supplementally provide us with more information about why you believe
the book value of InfraSource’s net tangible a ssets approximates their fair value.

38. We note that your preliminary purchase price allocation has assigned the vast
majority of your purchase price for In frasource to goodwill.  While we recognize
that this allocation is preliminary, it is not  clear to us from the current level of
disclosure that you have identified all of the other intangible assets t