UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

Commission file number 1-13831

Quanta Services, Inc.

(Exact name of registrant as specified in its charter)

1360 Post Oak Boulevard, Suite 2100

Houston, Texas 77056

(Address of principal executive offices, including ZIP Code)

(713) 629-7600

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

Title of Each Class

None

      Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days:     Yes þ          No o

      Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of Registrant’s knowledge, in definitive proxy or information statement incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.     o

      Indicate by check mark whether the Registrant is an accelerated filer (as defined in Exchange Act Rule 12b-2).     Yes þ          No o

      As of June 30, 2004, the aggregate market value of the Common Stock and Limited Vote Common Stock of the Registrant held by non-affiliates of the Registrant, based on the last sale price of the Common Stock on such date, was approximately $372.8 million and $4.5 million, respectively (for purposes of calculating these amounts, only directors, officers and beneficial owners of 5% or more of the outstanding capital stock of the Registrant have been deemed affiliates).

      As of March 10, 2005, the number of outstanding shares of the Common Stock of the Registrant was 116,086,371. As of the same date, 1,011,780 shares of Limited Vote Common Stock were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

      Portions of the Registrant’s Definitive Proxy Statement for the 2005 Annual Meeting of Stockholders are incorporated by reference into Part III of this Form 10-K.

QUANTA SERVICES, INC.

ANNUAL REPORT ON FORM 10-K

For the Year Ended December 31, 2004

INDEX

PART I

General

      Quanta is a leading provider of specialty contracting services, offering end-to-end network solutions to the electric power, gas, telecommunications, cable television, and specialty services industries. We believe that we are the largest contractor serving the transmission and distribution sector of the North American electric utility industry. Our consolidated revenues for the year ended December 31, 2004 were $1.6 billion, of which 64.7% was attributable to electric power and gas customers, 16.8% to telecommunications and cable television system operators and 18.5% to ancillary services, such as inside electrical wiring, intelligent traffic networks, cable and control systems for light rail lines, airports and highways, and specialty rock trenching, directional boring and road milling for industrial and commercial customers. We were organized in the state of Delaware in 1997 and since that time have made strategic acquisitions to expand our geographic presence, generate operating synergies with existing businesses and develop new capabilities to meet our customers’ evolving needs.

      We have established a nationwide presence with a workforce of over 10,000 employees, which enables us to quickly and reliably serve our diversified customer base. Our customers include many of the leading companies in the industries we serve.

      Representative customers include:

      Our reputation for responsiveness, performance, geographic reach and a comprehensive service offering has also enabled us to develop strong strategic alliances with numerous customers.

Industry Overview

      We estimate that the total amount of annual outsourced infrastructure spending in the three primary industries we serve is in excess of $30 billion. We believe that we are the largest specialty contractor providing services for the installation and maintenance of network infrastructure and that we and the other five largest specialty contractors providing these services account for less than 15% of this market. Smaller, typically private companies provide the balance of these services.

      We believe the following industry trends impact demand for our services:

      Increased opportunities in Fiber to the Premises, or FTTP, and Fiber to the Node, or FTTN. We believe that several of the large telecommunications companies are increasing their spending, particularly for FTTP and FTTN initiatives. Initiatives for this last-mile fiber build-out have been announced by Verizon and SBC as well as municipalities throughout the United States. In late 2004, Verizon added six states to its deployment plan, with a stated goal to access two million homes during 2005. SBC has announced plans to deliver Internet telephone service to 18 million homes by the end of 2007, including the installation of more than 38,000 miles of fiber at an estimated cost of $4 billion. This fiber will deliver integrated IP-based television, high-speed Internet and IP voice and wireless bundles of products and services. As a result of these efforts, we expect an increase in demand for our telecommunications and underground construction services over the next few years. While not all of this spending will be for services that we provide, we believe that we are well positioned to furnish infrastructure solutions on a rapid basis for these initiatives.

      Increased capital expenditures resulting from improved customer balance sheets. During the last several years, the industries we serve suffered a severe downturn that resulted in a number of companies, including several of our customers, filing for bankruptcy protection or experiencing financial difficulties. We believe that as our customers continue to improve their balance sheets, both capital spending and maintenance budgets will stabilize and move toward historical levels.

      Increased outsourcing of network infrastructure installation and maintenance. Financial and economic pressures on electric power, gas, telecommunications and cable television providers have caused an increased focus by providers on core competencies and, accordingly, an increase in the outsourcing of network services. Total employment in the electric utility industry declined dramatically in the last decade, reflecting, in part, the outsourcing trend by utilities. We believe that by outsourcing network services to third-party service providers, our customers can reduce costs, provide flexibility in budgets and improve service and performance. As a specialty contractor with nationwide scope, we are able to leverage our existing labor force and equipment infrastructure across multiple customers and projects, resulting in better utilization of labor and assets.

      Increasing need to upgrade electric power transmission and distribution networks. The nation’s electrical power grid is aging and requires significant maintenance and expansion to handle the country’s current and growing power needs. While the demand for electricity has grown, transmission capacity has decreased over the last ten years. The awareness of the need to upgrade the nation’s electrical power grid was heightened by the largest blackout in North America’s history on August 14, 2003. Additionally, as the selling of electricity increases across regional networks, capacity and reliability will become more important. We believe the current spending level is insufficient to adequately address future infrastructure maintenance requirements.

      Increased demand for comprehensive end-to-end solutions. We believe that electric power, gas, telecommunications and cable television companies will continue to seek service providers who can design, install and maintain their networks on a quick and reliable, yet cost effective basis. Accordingly, they are partnering with proven full-service network providers, like us, with broad geographic reach, financial capability and technical expertise.

Strengths

      Geographic reach and significant size and scale. As a result of our nationwide operations and significant scale, we are able to deploy services to customers across the United States. This capability is particularly important to our customers who operate networks that span multiple states or regions. The scale of our operations also allows us to mobilize significant numbers of employees on short notice for emergency service restoration. For example, after the damage from Hurricane Frances in August 2004, we quickly deployed approximately 1,300 workers to Florida to restore affected power lines.

      Strong financial profile. Our strong liquidity position provides us with the flexibility to capitalize on new business and growth opportunities. As of December 31, 2004, we had $265.6 million in cash and cash equivalents on our balance sheet and no significant debt obligations maturing before 2007.

      Strong and diverse customer relationships. We have established a solid base of long-standing customer relationships by providing high quality service in a cost-efficient and timely manner. We enjoy multi-year relationships with many of our customers. In some cases, these relationships are decades old. We derive a significant portion of our revenues from strategic alliances or long-term maintenance agreements with our customers, which we believe offer opportunities for future growth. For example, certain of our strategic alliances contain an exclusivity clause or a right of first refusal for a certain type of work or in a certain geographic region.

      Proprietary technology. Our electric power customers benefit from our ability to perform services without interrupting power service to their customers, which we refer to as energized services. Our proprietary LineMaster^tm robotic arm technology enhances our ability to deliver these energized services to our customers. We own the U.S. rights and the exclusive right to use the LineMaster^tm robotic arm for more than the next 10 years. We believe that delivery of energized services is a significant factor in differentiating us from

our competition and winning new business. Our energized services workforce is specially trained to deliver these services and operate the LineMaster^tm robotic arm.

      Delivery of comprehensive end-to-end solutions. We are one of the few network service providers capable of regularly delivering end-to-end solutions on a nationwide basis. As companies in the electric power, gas, telecommunications and cable television industries continue to search for service providers who can effectively design, install and maintain their networks, we believe that our service, industry and geographical breadth place us in a strong position to meet these needs.

      Experienced management team. Our senior management team has an average of 28 years of experience within the contracting industry, and our operating unit executives average over 25 years of experience in their respective industries.

Strategy

      The key elements of our business strategy are:

      Focus on expanding operating efficiencies. We intend to continue to:

      Focus on organic growth and leveraging existing customer relationships. We believe we can improve our rate of organic growth by expanding the breadth of products and solutions for our existing and potential customer base. We believe the combination of promoting best practices and cross-selling products to our customers positions us well for an improving end-market environment.

      Expand portfolio of services to meet customers’ evolving needs. We continue to offer an expanding portfolio of services that allows us to develop, build and maintain networks on both a regional and national scale and adapt to our customers’ changing needs. We intend to expand further our geographic and technological capabilities through both internal development and innovation and through selective acquisitions.

      Pursue new business opportunities. We continuously evaluate and pursue new business opportunities. Our subsidiary, Quanta Government Solutions (QGS), leverages our core expertise in pursuing additional opportunities in the government arena. QGS was formed to respond, as prime contractor, to requests for proposals from the U.S. government for power and communications infrastructure projects in the United States and overseas.

Services

      We design, install and maintain networks for the electric power, gas, telecommunications and cable television industries as well as commercial, industrial and governmental entities. The following provides an overview of the types of services we provide:

      Electric power and gas network services. We provide a variety of end-to-end services to the electric power and gas industries, including:

      Telecommunications and cable television network services. Our telecommunications and cable television network services include:

      Ancillary services. We provide a variety of comprehensive ancillary services to commercial, industrial and governmental entities, including:

Financial Information About Geographic Areas

      During the years ended December 31, 2002, 2003 and 2004, we operated primarily in the United States. We derived $8.5 million, $15.1 million and $22.8 million of our revenues from foreign operations during the years ended December 31, 2002, 2003 and 2004, respectively. As of December 31, 2002, 2003 and 2004, we held property and equipment in the amount of $1.0 million, $1.9 million and $3.1 million, respectively, in foreign countries.

      Our business, financial condition and results of operations in foreign countries may be adversely impacted by monetary and fiscal policies, currency fluctuations, energy shortages and other political, social and economic development.

Customers, Strategic Alliances and Preferred Provider Relationships

      Our customers include electric power, gas, telecommunications and cable television companies, as well as commercial, industrial and governmental entities. Our 10 largest customers accounted for 29.5% of our consolidated revenues in 2004. Our largest customer accounted for approximately 6.1% of our consolidated revenues for the year ended 2004.

      Although we have a centralized marketing strategy, management at each of our operating units is responsible for developing and maintaining successful long-term relationships with customers. Our management is incented to cross-sell services of other operating units to their customers. In addition, our business development group promotes and markets our services for prospective large national accounts and projects that would require services from multiple operating units.

      Many of our customers and prospective customers have qualification procedures for approved bidders or vendors based upon the satisfaction of particular performance and safety standards set by the customer. These customers typically maintain a list of vendors meeting these standards and award contracts for individual jobs only to those vendors. We strive to maintain our status as a preferred or qualified vendor to these customers.

      We believe that our strategic relationships with large providers of electric power and telecommunications services will offer opportunities for future growth. Many of these strategic relationships take the form of a strategic alliance or long-term maintenance agreement. Strategic alliance agreements generally state an intention to work together and many provide us with preferential bidding procedures. Strategic alliances and long-term maintenance agreements are typically agreements for an initial term of approximately two to four years that may include an option to add a one to two year extension at the end of the initial term. Certain of our strategic alliance and long-term maintenance agreements are “evergreen” contracts with exclusivity clauses providing that we will be awarded all contracts, or a right of first refusal, for a certain type of work or in a certain geographic region. None of these contracts, however, guarantees a specific dollar amount of work to be performed by us.

Backlog

      Backlog represents the amount of revenue that we expect to realize from work to be performed over the next twelve months on uncompleted contracts, including new contractual agreements on which work has not begun. Our backlog at December 31, 2003 and 2004 was approximately $1.01 billion and $1.07 billion. In many instances, our customers are not contractually committed to specific volumes of services under our long-term maintenance contracts and many of our contracts may be terminated with notice. There can be no assurance as to our customer’s requirements or that our estimates are accurate.

Competition

      The markets in which we operate are highly competitive. We compete with other independent contractors in most of the geographic markets in which we operate, and several of our competitors are large domestic

companies that may have greater financial, technical and marketing resources than we do. In addition, there are relatively few barriers to entry into some of the industries in which we operate and, as a result, any organization that has adequate financial resources and access to technical expertise may become a competitor. A significant portion of our revenues is currently derived from unit price or fixed price agreements, and price is often an important factor in the award of such agreements. Accordingly, we could be underbid by our competitors in an effort by them to procure such business. We believe that as demand for our services increases, customers will increasingly consider other factors in choosing a service provider, including technical expertise and experience, financial and operational resources, nationwide presence, industry reputation and dependability, which we expect to benefit contractors such as us. There can be no assurance, however, that our competitors will not develop the expertise, experience and resources to provide services that are superior in both price and quality to our services, or that we will be able to maintain or enhance our competitive position. We may also face competition from the in-house service organizations of our existing or prospective customers, including electric power, gas, telecommunications and cable television companies, which employ personnel who perform some of the same types of services as those provided by us. Although a significant portion of these services is currently outsourced by our customers, there can be no assurance that our existing or prospective customers will continue to outsource services in the future.

Employees

      As of December 31, 2004, we had 1,412 salaried employees, including executive officers, project managers or engineers, job superintendents, staff and clerical personnel and 9,408 hourly employees, the number of which fluctuates depending upon the number and size of the projects we undertake at any particular time. Approximately 46% of our employees at December 31, 2004 were covered by collective bargaining agreements, primarily with the International Brotherhood of Electrical Workers (IBEW). Under our agreements with our unions, we agree to pay specified wages to our union employees, observe certain workplace rules and make employee benefit payments to multi-employer pension plans and employee benefit trusts rather than administering the funds on behalf of these employees. These collective bargaining agreements have varying terms and expiration dates. The majority of the collective bargaining agreements contain provisions that prohibit work stoppages or strikes, even during specified negotiation periods relating to agreement renewal, and provide for binding arbitration dispute resolution in the event of prolonged disagreement.

      We provide a health, welfare and benefit plan for employees who are not covered by collective bargaining agreements. We have a 401(k) plan pursuant to which eligible employees who are not provided retirement benefits through a collective bargaining agreement may make contributions through a payroll deduction. We make matching cash contributions of 100% of each employee’s contribution up to 3% of that employee’s salary and 50% of each employee’s contribution between 3% and 6% of such employee’s salary, up to the maximum amount permitted by law. We also have an employee stock purchase plan that provides that eligible employees may contribute up to 10% of their cash compensation, not to exceed $21,250 annually, toward the semi-annual purchase of our common stock at a discounted price. Over 700 of our employees participated in the employee stock purchase plan during the year ended December 31, 2004.

      Our industry is experiencing a shortage of journeyman linemen in certain geographic areas. In response to the shortage, we seek to take advantage of various IBEW and National Electrical Contractors Association (NECA) referral programs and hire graduates from the joint IBEW/ NECA apprenticeship program which trains qualified electrical workers.

      We believe our relationships with our employees and union representatives are good.

Materials

      Our customers typically supply most or all of the materials required for each job. However, for some of our contracts, we may procure all or part of the materials required. We purchase such materials from a variety of sources and do not anticipate experiencing any difficulties in procuring such materials.

Training, Quality Assurance and Safety

      Performance of our services requires the use of equipment and exposure to conditions that can be dangerous. Although we are committed to a policy of operating safely and prudently, we have been and will continue to be subject to claims by employees, customers and third parties for property damage and personal injuries resulting from performance of our services. Our policies require that employees complete the prescribed training and service program of the operating unit for which they work in addition to those required, if applicable, by the IBEW and NECA prior to performing more sophisticated and technical jobs. For example, all journeyman linemen are required by the IBEW and NECA to complete a minimum of 7,000 hours of on-the-job training, approximately 200 hours of classroom education and extensive testing and certification. Each operating unit requires additional training, depending upon the sophistication and technical requirements of each particular job. We have established company-wide training and educational programs, as well as comprehensive safety policies and regulations, by sharing “best practices” throughout our operations.

Regulation

      Our operations are subject to various federal, state and local laws and regulations including:

      We believe that we have all the licenses required to conduct our operations and that we are in substantial compliance with applicable regulatory requirements. Our failure to comply with applicable regulations could result in substantial fines or revocation of our operating licenses.

Environmental Matters

      We are committed to the protection of the environment and train our employees to perform their duties accordingly. We are subject to numerous federal, state and local environmental laws and regulations governing our operations, including the handling, transportation and disposal of non-hazardous and hazardous substances and wastes, as well as emissions and discharges into the environment, including discharges to air, surface water and groundwater and soil. We also are subject to laws and regulations that impose liability and cleanup responsibility for releases of hazardous substances into the environment. Under certain of these laws and regulations, such liabilities can be imposed for cleanup of previously owned or operated properties, or properties to which hazardous substances or wastes were sent by current or former operations at our facilities, regardless of whether we directly caused the contamination or violated any law at the time of discharge or disposal. The presence of contamination from such substances or wastes could interfere with ongoing operations or adversely affect our ability to sell, lease, or use our properties as collateral for financing. In addition, we could be held liable for significant penalties and damages under environmental laws and could also be subject to a revocation of licenses or permits, which could materially and adversely affect our business and results of operations.

      From time to time, we may incur costs and obligations for correcting environmental noncompliance matters and for remediation at or relating to certain of our properties. We believe we have complied with, or are currently complying with, our environmental obligations to date and that such liabilities will not have a material adverse effect on our business or financial performance.

Risk Management and Insurance

      The primary risks in our operations are bodily injury and property damage. We are insured for employer’s liability and general liability claims, subject to a deductible of $1,000,000 per occurrence and for auto liability

and workers’ compensation claims subject to a deductible of $2,000,000 per occurrence. We also have a corporate non-union employee related health care benefit plan that is subject to a deductible of $250,000 per claimant per year. Losses up to the deductible amounts are accrued based upon our estimates of the ultimate liability for claims incurred and an estimate of claims incurred but not reported. The accruals are based upon known facts and historical trends and management believes such accruals to be adequate. However, insurance liabilities are difficult to assess and estimate due to the many relevant factors, the effects of which are often unknown, including the severity of an injury, the determination of our liability in proportion to other parties, the number of incidents not yet reported and the effectiveness of our safety program. In an effort to mitigate our exposure, we implemented a new company-wide safety initiative in 2004 to enhance our existing safety program.

      Our casualty insurance carrier for the policy periods from August 1, 2000 to February 28, 2003 is experiencing financial distress, but is currently paying valid claims. In the event that this insurer’s financial situation further deteriorates, we may be required to pay certain obligations that otherwise would have been paid by this insurer. We estimate that the total future claim amount that this insurer is currently obligated to pay on our behalf for the above-mentioned policy periods is approximately $4.0 million; however, our estimate of the potential range of these future claim amounts is between $2.0 million and $9.0 million. The actual amounts ultimately paid by us related to these claims, if any, may vary materially from the above range and could be impacted by further claims development and the extent to which the insurer could not honor its obligations. We continue to monitor the financial situation of this insurer and analyze any alternative actions that could be pursued. In any event, we do not expect any failure by this insurer to honor its obligations to us, or any alternative actions we may pursue, to have a material adverse impact on our financial condition; however, the impact could be material to our results of operations or cash flow in a given period.

Website Access

      Our website address is www.quantaservices.com. You may obtain free electronic copies of our Annual Reports on Form 10-K, Quarterly Reports on Form  10-Q, Current Reports on Form 8-K, and any amendments to these reports in our Investor Center under the heading “SEC Filings.” These reports are available on our website as soon as reasonably practicable after we electronically file them with, or furnish them to, the SEC. In addition, our corporate governance guidelines, Code of Ethics and Business Conduct and the charters of our Audit Committee, Compensation Committee and Governance and Nominating Committee are posted on our website under the heading “Corporate Governance.” We intend to disclose on our website any amendments or waivers to our Code of Ethics and Business Conduct that are required to be disclosed pursuant to Item 5.05 of Form 8-K. You may obtain free copies of these items from our website or by contacting our Corporate Secretary.

Annual CEO Certification

      As required by New York Stock Exchange rules, on June 11, 2004 we submitted an annual certification signed by our Chief Executive Officer certifying that he was not aware of any violation by us of New York Stock Exchange corporate governance listing standards as of the date of the certification.

Risk Factors

      Our business is subject to a variety of risks, including the risks described below. The risks and uncertainties described below are not the only ones facing our company. Additional risks and uncertainties not known to us or not described below may also impair our business operations. If any of the following risks actually occur, our business, financial condition and results of operations could be harmed and we may not be able to achieve our goals. This Annual Report also includes statements reflecting assumptions, expectations, projections, intentions, or beliefs about future events that are intended as “forward-looking statements” under the Private Securities Litigation Reform Act of 1995 and should be read in conjunction with the section entitled “Uncertainty of Forward-Looking Statements and Information.”

      Our operating results may vary significantly from quarter to quarter. We experience lower gross and operating margins during winter months due to lower demand for our services and more difficult operating conditions. Additionally, our quarterly results may also be materially and adversely affected by:

      Accordingly, our operating results in any particular quarter may not be indicative of the results that you can expect for any other quarter or for the entire year.

      An economic downturn may lead to less demand for our services. If the general level of economic activity remains slow or deteriorates further, our customers may delay or cancel new projects. The telecommunications and utility markets experienced substantial change during 2002 and 2003 as evidenced by an increased number of bankruptcies in the telecommunications market, continued devaluation of many of our customers’ debt and equity securities and pricing pressures resulting from challenges faced by major industry participants. These factors have contributed to the delay and cancellation of projects and reduction of capital spending that have impacted our operations and ability to grow at historical levels. A number of other factors, including financing conditions for and potential bankruptcies in the industries we serve, could adversely affect our customers and their ability or willingness to fund capital expenditures in the future or pay for past services. In addition, consolidation, competition or capital constraints in the electric power, gas, telecommunications or cable television industries may result in reduced spending by, or the loss of, one or more of our customers.

      Our industry is highly competitive. Our industry is served by numerous small, owner-operated private companies, a few public companies and several large regional companies. In addition, relatively few barriers prevent entry into some of our industries. As a result, any organization that has adequate financial resources and access to technical expertise may become one of our competitors. Competition in the industry depends on a number of factors, including price. Certain of our competitors may have lower overhead cost structures and may, therefore, be able to provide their services at lower rates than we are able to provide. In addition, some of our competitors have greater resources than we do. We cannot be certain that our competitors will not develop the expertise, experience and resources to provide services that are superior in both price and quality to our services. Similarly, we cannot be certain that we will be able to maintain or enhance our competitive position within our industry or maintain a customer base at current levels. We may also face competition from the in-house service organizations of our existing or prospective customers. Electric power, gas, telecommunications and cable television service providers usually employ personnel who perform some of the same types of services we do. We cannot be certain that our existing or prospective customers will continue to outsource services in the future.

      We extend credit to customers for purchases of our services, and in the past we have had, and in the future we may have, difficulty collecting receivables from major customers that have filed bankruptcy or are otherwise experiencing financial difficulties. We grant credit, generally without collateral, to our customers, which include electric power and gas companies, telecommunications and cable television system operators, governmental entities, general contractors, and builders, owners and managers of commercial and industrial properties located primarily in the United States. Consequently, we are subject to potential credit risk related to changes in business and economic factors throughout the United States. Our customers in the telecommunications business have experienced significant financial difficulties and in several instances have filed for bankruptcy. A number of our utility customers are also experiencing business challenges in the current business climate. If additional major customers file for bankruptcy or continue to experience financial difficulties, or if anticipated recoveries relating to receivables in existing bankruptcies or other workout situations fail to materialize, we could experience reduced cash flows and losses in excess of current allowances provided. In addition, material changes in any of our customer’s revenues or cash flows could affect our ability to collect amounts due from them. As of December 31, 2004, total current and non-current accounts and notes receivable were $368.7 million, net of allowances for doubtful accounts of $52.6 million.

      Our casualty insurance carrier for prior periods is experiencing financial distress, which may require us to make payments for losses that would otherwise be insured. Our casualty insurance carrier for the policy periods from August 1, 2000 to February 28, 2003 is experiencing financial distress, but is currently paying valid claims. In the event that this insurer’s financial situation deteriorates, we may be required to pay certain obligations that otherwise would have been paid by this insurer. We estimate that the total future claim amount that this insurer is currently obligated to pay on our behalf for the above-mentioned policy periods is approximately $4.0 million; however, our estimate of the potential range of these future claim amounts is between $2.0 million and $9.0 million. The actual amounts ultimately paid by us related to these claims, if any, may vary materially from the above range and could be impacted by further claims development and the extent to which the insurer can not honor its obligations. In any event, we do not expect any failure by this insurer to honor its obligations to us to have a material adverse impact on our financial condition; however, the impact could be material to our results of operations or cash flow in a given period.

      We are self-insured against potential liabilities. Although we maintain insurance policies with respect to automobile, general liability, workers’ compensation and employers’ liability, those policies are subject to deductibles of $1,000,000 to $2,000,000 per occurrence, and we are primarily self-insured for all claims that do not exceed the amount of the applicable deductible. We also maintain a non-union employee related health care benefit plan that is subject to a deductible of $250,000 per claimant per year. Losses up to the deductible amounts are accrued based upon our estimates of the ultimate liability for claims incurred and an estimate of claims incurred but not yet reported. However, insurance liabilities are difficult to assess and estimate due to unknown factors, including the severity of an injury, the determination of our liability in proportion to other parties, the number of incidents not reported and the effectiveness of our safety program. If we were to experience insurance claims or costs significantly above our estimates, our results of operations could be materially and adversely affected in a given period.

      We may incur liabilities or suffer negative financial impact relating to occupational health and safety matters. Our operations are subject to extensive laws and regulations relating to the maintenance of safe conditions in the workplace. While we have invested, and will continue to invest, substantial resources in our occupational health and safety programs, our industry involves a high degree of operational risk and there can be no assurance that we will avoid significant liability exposure. Although we have taken what we believe are appropriate precautions, we have suffered fatalities in the past and may suffer additional fatalities in the future. Claims for damages to persons, including claims for bodily injury or loss of life, could result in substantial costs and liabilities. In addition, if our safety record were to substantially deteriorate over time, our customers could cancel our contracts and not award us future business.

      Our use of percentage-of-completion accounting could result in a reduction or elimination of previously reported profits. As discussed in “Critical Accounting Policies” and in the notes to our consolidated financial statements included herein, a significant portion of our revenues is recognized on a percentage-of-completion method of accounting, using the cost-to-cost method. This method is used because management considers

expended costs to be the best available measure of progress on these contracts. This accounting method is standard for fixed-price contracts. The percentage-of-completion accounting practice we use results in our recognizing contract revenues and earnings ratably over the contract term in proportion to our incurrence of contract costs. The earnings or losses recognized on individual contracts are based on estimates of contract revenues, costs and profitability. Contract losses are recognized in full when determined, and contract profit estimates are adjusted based on ongoing reviews of contract profitability. Further, a substantial portion of our contracts contain various cost and performance incentives. Penalties are recorded when known or finalized, which is generally during the latter stages of the contract. In addition, we record cost recovery claims when we believe recovery is probable and the amounts can be reasonably estimated. Actual collection of claims could differ from estimated amounts and could result in a reduction or elimination of previously recognized earnings. In certain circumstances, it is possible that such adjustments could be significant.

      Our dependence upon fixed price contracts could adversely affect our business. We currently generate, and expect to continue to generate, a portion of our revenues under fixed price contracts. We must estimate the costs of completing a particular project to bid for fixed price contracts. The cost of labor and materials, however, may vary from the costs we originally estimated. These variations, along with other risks inherent in performing fixed price contracts, may cause actual revenue and gross profits for a project to differ from those we originally estimated and could result in reduced profitability or losses on projects. Depending upon the size of a particular project, variations from the estimated contract costs can have a significant impact on our operating results for any fiscal quarter or year.

      The industries we serve are subject to rapid technological and structural changes that could reduce the demand for the services we provide. The electric power, gas, telecommunications and cable television industries are undergoing rapid change as a result of technological advances that could, in certain cases, reduce the demand for our services or otherwise negatively impact our business. New or developing technologies could displace the wireline systems used for voice, video and data transmissions, and improvements in existing technology may allow telecommunications and cable television companies to significantly improve their networks without physically upgrading them.

      A portion of our business depends on our ability to provide surety bonds. We may be unable to compete for or work on certain projects if we are not able to obtain the necessary surety bonds. Surety market conditions are currently difficult as a result of significant losses incurred by many sureties in recent periods, both in the construction industry as well as in certain larger corporate bankruptcies. As a result, less bonding capacity is available in the market and terms have become more expensive and restrictive. We have posted a $10.0 million letter of credit to support our surety bond program and have granted security interests in various of our assets to collateralize our obligations to the surety. Further, under standard terms in the surety market, sureties issue or continue bonds on a project-by-project basis and can decline to issue bonds at any time or require the posting of additional collateral as a condition to issuing or renewing any bonds.

      Current or future market conditions, as well as changes in our surety’s assessment of our operating and financial risk, could cause our surety provider to decline to issue or renew, or substantially reduce the amount of, bonds for our work and could increase our bonding costs. These actions can be taken on short notice. If our surety provider were to limit or eliminate our access to bonding, our alternatives would include seeking bonding capacity from other sureties, finding more business that does not require bonds and posting other forms of collateral for project performance, such as letters of credit or cash. We may be unable to secure these alternatives in a timely manner, on acceptable terms, or at all. Accordingly, if we were to experience an interruption or reduction in the availability of bonding capacity, we may be unable to compete for or work on certain projects.

      Many of our contracts may be canceled on short notice, and we may be unsuccessful in replacing our contracts if they are cancelled or as they are completed or expire. We could experience a decrease in our revenue, net income and liquidity if any of the following occur:

      Many of our customers may cancel our contracts on short notice, typically 30-90 days, even if we are not in default under the contract. Certain of our customers assign work to us on a project-by-project basis under master service agreements. Under these agreements, our customers often have no obligation to assign a specific amount of work to us. Our operations could decline significantly if the anticipated volume of work is not assigned to us. Many of our contracts, including our master service contracts, are opened to public bid at the expiration of their terms. There can be no assurance that we will be the successful bidder on our existing contracts that come up for bid.

      We may be unsuccessful at integrating companies that we either have acquired or that we may acquire in the future. We cannot be sure that we can successfully integrate our acquired companies with our existing operations without substantial costs, delays or other operational or financial problems. If we do not implement proper overall business controls, our decentralized operating strategy could result in inconsistent operating and financial practices at the companies we acquire and our overall profitability could be adversely affected. Integrating our acquired companies involves a number of special risks which could have a negative impact on our business, financial condition and results of operations, including:

If one of our acquired companies suffers customer dissatisfaction or performance problems, the reputation of our entire company could suffer.

      The departure of key personnel could disrupt our business. We depend on the continued efforts of our executive officers and on senior management of the businesses we acquire. Although we have entered into employment agreements with terms of one to three years with most of our executive officers and certain other key employees, we cannot be certain that any individual will continue in such capacity for any particular period of time. The loss of key personnel, or the inability to hire and retain qualified employees, could negatively impact our ability to manage our business. We do not carry key-person life insurance on any of our employees.

      Our unionized workforce could adversely affect our operations and our ability to complete future acquisitions. As of December 31, 2004, approximately 46% of our employees were covered by collective bargaining agreements. Although the majority of these agreements prohibit strikes and work stoppages, we cannot be certain that strikes or work stoppages will not occur in the future. Strikes or work stoppages would adversely impact our relationships with our customers and could cause us to lose business and decrease our revenue. In addition, our ability to complete future acquisitions could be adversely affected because of our union status for a variety of reasons. For instance, our union agreements may be incompatible with the union agreements of a business we want to acquire and some businesses may not want to become affiliated with a union based company.

      Our business is labor intensive, and we may be unable to attract and retain qualified employees. Our ability to maintain our productivity and profitability will be limited by our ability to employ, train and retain skilled personnel necessary to meet our requirements. We may experience shortages of qualified journeyman linemen. We cannot be certain that we will be able to maintain an adequate skilled labor force necessary to operate efficiently and to support our growth strategy or that our labor expenses will not increase as a result of

a shortage in the supply of these skilled personnel. Labor shortages or increased labor costs could impair our ability to maintain our business or grow our revenues.

      Our business growth could outpace the capability of our corporate management infrastructure. We cannot be certain that our infrastructure will be adequate to support our operations as they expand. Future growth also could impose significant additional responsibilities on members of our senior management, including the need to recruit and integrate new senior level managers and executives. We cannot be certain that we can recruit and retain such additional managers and executives. To the extent that we are unable to manage our growth effectively, or are unable to attract and retain additional qualified management, we may not be able to expand our operations or execute our business plan.

      Our failure to comply with environmental laws could result in significant liabilities. Our operations are subject to various environmental laws and regulations, including those dealing with the handling and disposal of waste products, PCBs, fuel storage and air quality. We perform work in many different types of underground environments. If the field location maps supplied to us are not accurate, or if objects are present in the soil that are not indicated on the field location maps, our underground work could strike objects in the soil, some of which may contain pollutants. In such cases, these objects may rupture, resulting in the discharge of pollutants. If we are unable to obtain reimbursement from the parties providing the incorrect information, we may be liable for fines and damages. In addition, we perform directional drilling operations below certain environmentally sensitive terrains and water bodies. Due to the inconsistent nature of the terrain and water bodies, it is possible that such directional drilling may cause a surface fracture releasing subsurface materials. These releases may contain contaminants in excess of amounts permitted by law, potentially exposing us to remediation costs and fines. We own and lease several facilities at which we store our equipment. Some of these facilities contain fuel storage tanks which may be above or below ground. If these tanks were to leak, we could be responsible for the cost of remediation as well as potential fines.

      In addition, new laws and regulations, stricter enforcement of existing laws and regulations, the discovery of previously unknown contamination or leaks, or the imposition of new clean-up requirements could require us to incur significant costs or become the basis for new or increased liabilities that could harm our financial condition and results of operations. In certain instances, we have obtained indemnification or covenants from third parties (including predecessors or lessors) for such cleanup and other obligations and liabilities that we believe are adequate to cover such obligations and liabilities. However, such third-party indemnities or covenants may not cover all of our costs, and such unanticipated obligations or liabilities, or future obligations and liabilities, may have a material adverse effect on our business operations or financial condition. Further, we cannot be certain that we will be able to identify or be indemnified for all potential environmental liabilities relating to any acquired business.

      Opportunities within the government arena could lead to increased governmental regulation applicable to Quanta and unrecoverable start up costs. Most government contracts are awarded through a regulated competitive bidding process. As we pursue increased opportunities in the government arena management’s focus associated with the start up and bidding process may be diverted away from other opportunities. If we were to be successful in being awarded government contracts, a significant amount of costs could be required before any revenues were realized from these contracts. In addition, as a government contractor we would be subject to a number of procurement rules and other public sector liabilities, any deemed violation of which could lead to fines or penalties or a loss of business. Government agencies routinely audit and investigate government contractors. Government agencies may review a contractor’s performance under its contracts, cost structure, and compliance with applicable laws, regulations and standards. If government agencies determine through these audits or reviews that costs were improperly allocated to specific contracts, they will not reimburse the contractor for those costs or may require the contractor to refund previously reimbursed costs. If government agencies determine that we engaged in improper activity, we may be subject to civil and criminal penalties. In addition, if the government were to even allege improper activity, we also could experience serious harm to our reputation. Many government contracts must be appropriated each year. If appropriations are not made in subsequent years we would not realize all of the potential revenues from any awarded contracts.

      We may not be successful in continuing to meet the requirements of the Sarbanes-Oxley Act of 2002. The Sarbanes-Oxley Act of 2002 has introduced many requirements applicable to us regarding corporate governance and financial reporting, including the requirements, beginning with this 2004 Annual Report, for management to report on our internal controls over financial reporting and for our independent registered public accounting firm to attest to this report. During 2004, we continued actions to ensure our ability to comply with these requirements, including but not limited to, the engaging of outside experts to assist in the evaluation of our controls, adding staff to our internal audit department and documenting our existing controls. As of December 31, 2004, we were in compliance, however, there can be no assurance that we will be successful in complying in future years. Failure to maintain compliance could result in a decrease in the market value of our common stock and other publicly-traded securities, the reduced ability to obtain financing, the loss of customers, penalties and additional expenditures to meet the requirements.

      We may not have access in the future to sufficient funding to finance desired growth. If we cannot secure additional financing in the future on acceptable terms, we may be unable to support our growth strategy. We cannot readily predict the ability of certain customers to pay for past services or the timing, size and success of our acquisition efforts. Using cash for acquisitions limits our financial flexibility and makes us more likely to seek additional capital through future debt or equity financings. Our existing debt agreements contain significant restrictions on our operational and financial flexibility, including our ability to incur additional debt, and if we seek more debt we may have to agree to additional covenants that limit our operational and financial flexibility. When we seek additional debt or equity financings, we cannot be certain that additional debt or equity will be available to us on terms acceptable to us or at all.

      We may be unsuccessful at generating internal growth. Our ability to generate internal growth will be affected by, among other factors, our ability to:

      In addition, our customers may reduce the number or size of projects available to us due to their inability to obtain capital or pay for services provided. Many of the factors affecting our ability to generate internal growth may be beyond our control, and we cannot be certain that our strategies will be successful or that we will be able to generate cash flow sufficient to fund our operations and to support internal growth. If we are unsuccessful, we may not be able to achieve internal growth, expand our operations or grow our business.

      Our results of operations could be adversely affected as a result of goodwill impairments. When we acquire a business, we record an asset called “goodwill” equal to the excess amount we pay for the business, including liabilities assumed, over the fair value of the tangible and intangible assets of the business we acquire. Through December 31, 2001, pursuant to generally accepted accounting principles, we amortized this goodwill over its estimated useful life of 40 years following the acquisition, which directly impacted our earnings. The Financial Accounting Standards Board (FASB) issued Statement of Financial Accounting Standards (SFAS) No. 142 which provides that goodwill and other intangible assets that have indefinite useful lives not be amortized, but instead must be tested at least annually for impairment, and intangible assets that have finite useful lives should continue to be amortized over their useful lives. SFAS No. 142 also provides specific guidance for testing goodwill and other non-amortized intangible assets for impairment. SFAS No. 142 requires management to make certain estimates and assumptions to allocate goodwill to reporting units and to determine the fair value of reporting unit net assets and liabilities, including, among other things, an assessment of market conditions, projected cash flows, investment rates, cost of capital and growth rates, which could significantly impact the reported value of goodwill and other intangible assets. Fair value is determined using a combination of the discounted cash flow, market multiple and market

capitalization valuation approaches. Absent any impairment indicators, we perform our impairment tests annually during the fourth quarter. Future impairments, if any, will be recognized as operating expenses.

      A number of shares of our common stock are eligible for future sale, which may cause our stock price to decline. The market price of our common stock could decline as a result of sales of a large number of shares of common stock in the public market or the perception that such sales could occur. These sales, or the possibility that these sales may occur, also might make it more difficult for us to sell equity securities in the future at a time and at a price that we deem appropriate. Shares of common stock issued upon the conversion of our $270.0 million issuance of 4.5% convertible subordinated notes could cause substantial dilution to existing stockholders, which could cause the market price of our common stock to decline.

      First Reserve Fund IX, L.P., which owned approximately 15.2 million shares of our common stock as of December 31, 2004 has the ability to cause us to register the resale of its shares under its investor’s rights agreement. First Reserve Fund IX, L.P. may also sell such shares in the open market subject to the volume, manner of sale and other conditions of Rule 144.

      You are unlikely to be able to seek remedies against Arthur Andersen LLP, our former independent auditor. Our consolidated financial statements for the fiscal years ended prior to December 31, 2002 were audited by Arthur Andersen LLP, our former independent auditor. In June 2002 Arthur Andersen LLP was convicted of federal obstruction of justice charges in connection with its destruction of documents. As a result of its conviction, Arthur Andersen LLP has ceased operations. You will not be able to recover against Arthur Andersen LLP for its liability under Section 11 of the Securities Act in the event of any untrue statements of a material fact contained in the periods covered by its previously issued audit reports. Even if you have a basis for asserting a remedy against, or seeking to recover from Arthur Andersen LLP, because they have ceased operations, it is highly unlikely that you would be able to recover damages from Arthur Andersen LLP.

      Certain provisions of our corporate governing documents could make an acquisition of our company more difficult. The following provisions of our certificate of incorporation and bylaws, as currently in effect, as well as our stockholder rights plan and Delaware law, could discourage potential proposals to acquire us, delay or prevent a change in control of us or limit the price that investors may be willing to pay in the future for shares of our common stock:

Facilities

      We lease our corporate headquarters in Houston, Texas and maintain offices nationwide. This space is used for offices, equipment yards, warehousing, storage and vehicle shops. We own 32 of the facilities we occupy, all of which are encumbered by our credit facility, and we lease the remainder. We believe that our existing facilities are sufficient for our current needs.

Equipment

      We operate a fleet of owned and leased trucks and trailers, support vehicles and specialty construction equipment, such as backhoes, excavators, trenchers, generators, boring machines, cranes, wire pullers and tensioners, all of which are encumbered by our credit facility. As of December 31, 2004, the total size of the rolling-stock fleet was approximately 19,600 units. Most of this fleet is serviced by our own mechanics who work at various maintenance sites and facilities. We believe that these vehicles generally are well maintained and adequate for our present operations.