EXHIBIT 21.1
QUANTA SERVICES, INC. - SUBSIDIARIES LIST
The following is a list of the significant subsidiaries of Quanta Services, Inc.
showing the place of incorporation or organization and the names under which
each subsidiary does business. The names of certain subsidiaries are omitted as
such subsidiaries, considered as a single subsidiary, would not constitute a
significant subsidiary.
<Table>
<Caption>
SUBSIDIARY/DOING BUSINESS AS STATE OF INCORPORATION/ORGANIZATION
- ---------------------------- -----------------------------------
Advanced Technologies and Installation Corporation Washington
Allteck Line Contractors (USA), Inc. Washington
Allteck Line Contractors, Inc. British Columbia
Arby Construction, Inc. Delaware
Austin Trencher, Inc. Delaware
Bradford Brothers, Inc. North Carolina
CCLC, Inc. Delaware
Coast to Coast, LLC California
CMI Services, Inc. Florida
Conti Communications, Inc. Delaware
DE Conti Communications, Inc.
Croce Electric Company, Inc. Delaware
Crown Fiber Communications, Inc. Virginia
Myers Cable, Inc.
World Fiber
Digco Utility Construction, L.P. Texas
Brown Engineering
Ranger Field Services
Dillard Smith Construction Company Delaware
Driftwood Electrical Contractors, Inc. Delaware
Maddux Communications
Environmental Professional Associates, Limited California
Provco
Five Points Construction Co. Texas
Global Enercom Management, Inc. Delaware
Golden State Utility Co. Delaware
H.L. Chapman Pipeline Construction, Inc. Delaware
DB Utilities
Sullivan Welding
Intermountain Electric, Inc. Colorado
Colorado IM Electric
Grand Electric
Irby Construction Company Mississippi
Lindsey Electric, L.P. Texas
Manuel Bros., Inc. Delaware
Renaissance Construction
Western Directional
</Table>
<Table>
<Caption>
SUBSIDIARY/DOING BUSINESS AS STATE OF INCORPORATION/ORGANIZATION
- ---------------------------- -----------------------------------
Mears Canada Corp. Nova Scotia
Mears Engineering/LLC Michigan
Mears Group, Inc. Delaware
Mears Services LLC Michigan
Mears/CPG LLC Michigan
Mears/HDD LLC Michigan
Mearsmex S. de R.L. de C.V. Mexico
Mejia Personnel Services, Inc. Texas
Metro Underground Services, Inc. of Illinois Illinois
Network Electric Company Delaware
DE Network Electric Company
North Houston Pole Line, L.P. Delaware
North Houston Pole Line Corp.
North Sky Communications, Inc. Delaware
Sky Communications
Okay Construction Company, LLC Delaware
PAR Electrical Contractors, Inc. Missouri
Par Infrared Consultants
Riggin & Diggin Line Construction
Seaward
Seaward Corporation
Par Internacional, S. de R.L. de C.V. Mexico
Parkside Site & Utility Company Corporation Delaware
Parkside Utility Construction Corp. Delaware
Potelco, Inc. Washington
Kingston Constructors DBA Talking Sign
Services
Kuenzi Constructors
Potelco Incorporated
Professional Teleconcepts, Inc. Illinois
JT Communications
Professional Teleconcepts, Inc. New York
PWR Financial Company Delaware
PWR Network, LLC Delaware
Q Resources, LLC Delaware
QDE LLC Delaware
QPC, Inc. Delaware
QSI, Inc. Delaware
Quanta Asset Management LLC Delaware
Quanta Associates, L.P. Texas
Quanta Delaware, Inc. Delaware
Quanta Government Services, Inc. Delaware
Quanta Government Solutions, Inc. Delaware
Quanta International Limited British Virgin Islands
</Table>
<Table>
<Caption>
SUBSIDIARY/DOING BUSINESS AS STATE OF INCORPORATION/ORGANIZATION
- ---------------------------- -----------------------------------
Quanta Receivables, L.P. Delaware
Quanta Services Management Partnership, L.P. Texas
Quanta Services of Canada Ltd. British Columbia
Quanta Utility Installation Co., Inc. Delaware
Quanta Utility Services, LLC Delaware
R.A. Waffensmith & Co., Inc. Delaware
S.K.S. Pipeliners, LLC Delaware
Servicios Par Electric, S. de R.L. de C.V. Mexico
Southeast Pipeline Construction, Inc. Delaware
Southwestern Communications, Inc. Delaware
Southwestern Communications/Utilities, Inc.
NetCom Management Group
Southwest Trenching Company, Inc. Texas
Spalj Construction Company Delaware
Dot 05 Optical Communications
Delaware Spaj Construction Company
Smith Contracting
Span-Con of Deerwood
Tjader & Highstrom
Throstad Brother Tiling
Wilson Roadbores
Sumter Utilities, Inc. Delaware
Sumter Builders Construction Contracting
The Ryan Company, Inc. Massachusetts
Eastern Communications
The Ryan Company Inc. of Massachusetts
The Ryan Company of Massachusetts
The Ryan Company Incorporated of
Massachusetts
The Ryan Company, Incorporated Electrical
Contractors
Ryan Company Inc. (The)
Tjader, L.L.C. Delaware
TNS-VA, LLC Delaware
Tom Allen Construction Company Delaware
TA Construction
Total Quality Management Services, LLC Delaware
Trans Tech Acquisition, Inc. Texas
Trans Tech Electric, L.P. Texas
Trans Tech Electric, Limited Partnership
Trawick Construction Co. Florida
TTGP, Inc. Delaware
TTLP, Inc. Delaware
TTM, Inc. North Carolina
</Table>
<Table>
<Caption>
SUBSIDIARY/DOING BUSINESS AS STATE OF INCORPORATION/ORGANIZATION
- ---------------------------- -----------------------------------
TXLP, Inc. Delaware
Underground Construction Co., Inc. Delaware
Delaware Underground Construction Co.
Maryland Underground Construction Co., Inc.
Underground Construction Co., Inc. (Delaware)
Utility Line Management Services, Inc. Delaware
VCI Telcom, Inc. Delaware
W.C. Communications, Inc. Delaware
West Coast Communications
W.H.O.M. Corporation California
</Table>