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PRIMORIS SERVICES CORPORATION

26000 Commercentre Drive

Lake Forest, California 92630

www.primoriscorp.com

NOTICE OF THE SPECIAL MEETING OF

STOCKHOLDERS OF PRIMORIS SERVICES CORPORATION

TO BE HELD ON                            , 2010

To the Stockholders of Primoris Services Corporation:

A special meeting of the stockholders of Primoris Services Corporation, a Delaware corporation (“our,” the “Company” or “Primoris”), will be held on                            , 2010, at            A.M., Pacific Standard Time, at                     , for the following purposes:

1.To approve of the issuance of (a) 8,185,278 shares of common stock issuable upon the conversion of the shares of Series A Non-Voting Contingent Convertible Preferred Stock issued in connection with the acquisition of James Construction Group, L.L.C., and (b) up to 6,508,276 shares of common stock, which shares of common stock may be issued as earnout consideration in connection with the acquisition of James Construction Group, L.L.C.;

2.To approve of the conversion of 81,852.78 shares of our Series A Non-Voting Contingent Convertible Preferred Stock into 8,185,278 shares of common stock, which shares of Series A Non-Voting Contingent Convertible Preferred Stock were issued in connection with the acquisition of James Construction Group, L.L.C.; and

3.To transact such other business that may properly come before the special meeting or any adjournment or postponement thereof.

The board of directors has fixed the close of business on                          , 2010 as the record date for the determination of the stockholders entitled to notice of, and to vote at, the special meeting and any adjournment or postponement thereof.   Only stockholders who owned shares of our common stock at the close of business on the record date are entitled to notice of, and to vote at, the special meeting and any adjournment or postponement thereof.  Each share of our common stock is entitled to one vote on all matters presented at the special meeting.

Please vote.  Whether or not you expect to attend the special meeting in person, please vote by completing, signing and dating the enclosed proxy card and returning it promptly in the postage-paid reply envelope provided.  The proxy is revocable by you in accordance with the procedures set forth in this proxy statement.  If you are a stockholder of record, you may also cast your vote in person at the special meeting.  If you receive more than one proxy card because your shares of common stock are registered in different names or addresses, each proxy card should be signed and returned to ensure that all your shares of common stock will be voted at the special meeting.  If your shares of common stock are held at a brokerage firm or a bank, you must provide them with instructions on how to vote your shares of common stock.

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RISK FACTORS

Before you make your decision regarding how to vote on the proposals set forth in this proxy statement, you should carefully consider each of the following risk factors and all of the other information contained in this proxy statement.  The risk factors described below relate primarily to the Acquisition, the consideration paid or to be paid to the Members and the business of the combined company.  We and JCG are also subject to certain additional risks and uncertainties inherent to the construction industry.  A description of these construction industry-specific risk factors is contained in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2008, which we filed with the Commission on March 24, 2009, and in our subsequently filed quarterly reports on Form 10-Q, which are incorporated herein by reference.   The risk factors described below are not the only risks that we will face following the Acquisition.  Additional risks and uncertainties not currently known to us may also materially and adversely affect our business operations and financial condition or the price of our common stock.

Risks Relating to the Acquisition

Cash expenditures and potential capital expenditures associated with the Acquisition may create significant liquidity and cash flow risks for us, and we may incur substantial debt in order to satisfy our obligations.

Our principal sources of liquidity are our cash and cash equivalents and our credit facilities.  We currently have a revolving line of credit in the total aggregate amount of $35 million, comprised of two revolving loans in the amounts of $15 million and $20 million, with maturity dates of October 27, 2010 and October 28, 2012, respectively, and a $10 million (Canadian dollars) facility for commercial letters of credit in Canada with an expiration date of December 31, 2012.  At September 30, 2009, we had no amounts outstanding on the revolving line of credit and we had outstanding $700,000 (Canadian dollars) in letters of credit.  At September 30, 2009, our adjusted cash and cash equivalent balance totaled $80.3 million.  The cash expenditures required in connection with the Acquisition were substantial.  On the closing date, we paid certain of the Members a cash payment of $7 million and issued a Promissory Note in favor of all of the Members in the principal amount of $53.5 million.  In addition, we also incurred significant transaction expenses in connection with the Acquisition.

The line of credit facilities contain various restrictive covenants, including, among other things, restrictions on investments, capital expenditures, minimum working capital and tangible net worth requirements.  Violation of those covenants would place us in default, so we must manage our financial condition carefully.  Although in recent years we have generated sufficient net cash from our operations to meet our capital requirements, we will be substantially larger with greater operating cash needs as a result of the Acquisition.  If actual results fail to meet our expectations regarding the revenues and expenses of the acquired business, our historical cash flows may not be sufficient to meet our capital requirements.  If additional funding is required for operations, to cure loan defaults or for other purposes, we may attempt to seek funds from time to time through public or private equity or debt financing, although additional funds may not be available on terms acceptable to us or at all.  We may also decide to raise additional capital at such times and upon such terms as management considers favorable and in our interests.  Under the terms of the Purchase Agreement, however, until such time as the Closing Shares have been converted into shares of common stock, we have agreed not to issue any shares of our common stock, preferred stock or other securities convertible into shares of common stock or preferred stock except:

·to the Members;

·pursuant to transfers of shares of common stock issued and outstanding as of November 18, 2009; and

·pursuant to existing common stock purchase warrants and stock options.

The failure of our stockholders to approve the conversion of the Closing Shares could adversely affect our ability to raise additional capital, if needed, which, in turn, could have a material adverse effect on our operations and financial condition.

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If our stockholders approve the conversion of the Closing Shares and the issuance of the shares of common stock issuable upon the conversion of the Closing Shares, our stockholders will be diluted.  In addition, if our stockholders approve the issuance of the Earnout Shares, and we are ultimately required to issue such shares, our stockholders will experience further dilution.

Prior to the closing of the Acquisition, we had 32,704,903 shares of common stock outstanding.  If our stockholders approve the conversion of the Closing Shares, the Closing Shares will automatically convert into 8,185,278 shares of common stock, which would represent an increase of approximately 25% in the number of shares of common stock outstanding prior to the Acquisition and result in a dilution of the existing ownership interests of our common stockholders.

In addition, if JCG’s EBITDA, as defined in the Purchase Agreement, for the fiscal year ending December 31, 2010 is equal to or greater than $35 million, we have agreed to pay the Members, as earnout consideration, a number of shares of common stock equal to $10 million, divided by the average closing price of our common stock, as reported on NASDAQ, for the 20 business days prior to December 31, 2010.  Although we cannot currently determine the number of Earnout Shares, if any, that we may be required to issue at the end of the earnout period, the issuance of any Earnout Shares would result in further dilution of the existing ownership interests of our common stockholders.  By way of illustration, if we were required to issue the maximum number of Earnout Shares, we would be required to issue an additional 6,508,276 shares of common stock, which would represent a 19.9% increase in the number of shares of common stock outstanding prior to the Acquisition and, according to the formula above, would reflect a 20-day average closing price of $1.54 per common share.

If our stockholders approve both proposals set forth in this proxy statement and the maximum number of Earnout Shares become issuable, the total number of shares of common stock issued in connection with the Acquisition would represent an approximately 45% increase in the number of shares of common stock outstanding prior to the Acquisition, resulting in substantial dilution of the existing ownership interests of our common stockholders.

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The actual value of the consideration potentially payable to the Members pursuant to the Purchase Agreement may exceed the nominal value specified in the Purchase Agreement.

Under the Purchase Agreement, as part of the consideration for the Acquisition, we agreed to issue additional contingent shares, or Earnout Shares, for a value of $10 million should certain financial milestones be achieved.  The Purchase Agreement provides that the value of the Earnout Shares would be based on the average closing price of our common stock, as reported on NASDAQ, for the 20 business days prior to December 31, 2010.  Because we will calculate an average share price, rather than establish the value as of the closing share price on December 31, 2010, there may be a difference to the value between the two amounts.  This could result in providing a value for the Acquisition consideration greater than the indicated value of $10 million.

As shares of our common stock issued in connection with the Acquisition become eligible for public resale, the sale of those shares could adversely impact our stock price.

Subject to certain specified exceptions and limitations, we granted the Members “piggyback” registration rights, pursuant to which we have agreed to use our reasonable best efforts to include the shares of common stock issuable upon the conversion of the Closing Shares and the Earnout Shares in any registration statement (other than pursuant to a registration statement on Forms S-4 or S-8 or any successor or similar forms, or a registration on any form that does not permit secondary sales) that we file after the closing date.  If we file a registration statement including such shares and the registration statement is declared effective, a substantial number of shares of our common stock would become eligible for public resale.  Even if we did not file a registration statement, certain of such shares may become eligible for public resale at the end of the applicable holding period under Rule 144 of the Securities Act.  Our stock price may suffer a significant decline as a result of the sudden increase in the number of shares of common stock sold in the public market or market perception that the increased number of shares of common stock available for sale will exceed the demand for our common stock.

Our integration with JCG may not be completed successfully, cost-effectively or on a timely basis.

We have significantly more assets and employees to manage than we did prior to the Acquisition.  The integration process will require us to significantly expand the scope of our operations and financial systems.  Our management will be required to devote a significant amount of time and attention to the process of integrating us with JCG.  There is a significant degree of difficulty and management involvement inherent in that process.  These difficulties include, among others:

·the diversion of management’s attention from the day-to-day operations of the combined company;

·the management of a significantly larger company than before completion of the Acquisition;

·the assimilation of JCG employees and the integration of two business cultures;

·retaining key personnel;

·the integration of information, accounting, finance, sales, billing, payroll and regulatory compliance systems;

·challenges in keeping existing customers and obtaining new customers; and

·challenges in combining service offerings and sales and marketing activities.

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There can be no assurance that we will successfully or cost-effectively integrate JCG’s operations with our own and the costs of achieving systems integration may substantially exceed our current estimates.  For example, because JCG was formerly a privately-held company, JCG has not had to comply with the requirements of the Sarbanes-Oxley Act of 2002 for internal controls and other procedures.  Bringing its systems into compliance with those requirements may cause us to incur substantial additional expense.  In addition, the integration process may cause an interruption of or loss of momentum in the activities of our business after the Acquisition.  If our management is not able to effectively manage the integration process or if any significant business activities are interrupted as a result of the integration process, our business could suffer and our results of operations and financial condition may be negatively affected.

We may not be able to realize the benefits we expect to achieve from the Acquisition.

Strategic transactions like the Acquisition create numerous uncertainties and risks.  The combined company may not be able to realize the expected revenue growth and other benefits that we seek to achieve from the Acquisition.  We believe that our businesses are complementary in a number of respects and that the combined company can take advantage of economies of scale and other benefits in the following areas, among others:

·market expansion;

·increased sales to existing customers;

·service and technology synergies;

·operational synergies;

·materials and suppliers;

·geographic synergies; and

·cultural synergies.

However, these anticipated benefits are based on projections and assumptions, not actual experience, and actual results may deviate from our expectations for a variety of reasons, including those discussed in these risk factors and elsewhere in this proxy statement.

The addition of two new directors to our board of directors may have an anti-takeover effect.

Pursuant to the Purchase Agreement, we created two new “Class C” directorships with terms expiring at the 2011 annual meeting of our stockholders.  The size of our board of directors increased from eight to ten members.  The increase in size of our board of directors could, under certain circumstances, have an anti-takeover effect.  The expansion of the board of directors may discourage a potential acquirer from seeking to acquire shares of our common stock (whether by making a tender offer or otherwise) or otherwise attempting to obtain control of us, or make such process more difficult.

If our stockholders approve of the conversion of the Closing Shares, we will no longer be deemed to be a “controlled company” pursuant to the NASDAQ listing requirements and will no longer be exempt from certain corporate governance requirements.

Currently, Brian Pratt, our chief executive officer, president and chairman, holds in excess of 50% of our voting power for the election of directors.  As a result, we are currently considered a “controlled company” pursuant to NASDAQ Listing Rule 5615(c).  A controlled company is a company of which more than 50% of the voting power for the election of directors is held by an individual, a group or another company.  As a controlled company, we are currently exempt from certain NASDAQ corporate governance requirements, including:

·NASDAQ Listing Rule 5605(b), which requires that a majority of our board of directors be comprised of independent directors;

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·NASDAQ Listing Rule 5605(d), which requires that compensation of our chief executive officer and all other executive officers must be determined or recommended to the board of directors for determination by (a) independent directors constituting a majority of the board of directors’ independent directors in a vote in which only independent directors participate or (b) a compensation committee comprised solely of independent directors; and

·NASDAQ Listing Rule 5605(e), which requires that director nominees must either be selected or recommended for the board of directors’ selection by (a) independent directors constituting a majority of the board of directors’ independent directors in a vote in which only independent directors participate or (b) a nominations committee comprised solely of independent directors.

Currently, we voluntarily comply with NASDAQ Listing Rule 5605(b) because our board of directors is comprised of a majority of independent directors.  However, in reliance on the controlled company exemption, we do not currently comply with NASDAQ Listing Rules 5605(d) and (e). If our stockholders approve the conversion of the Closing Shares, Mr. Pratt will no longer beneficially hold greater than 50% of our voting power for the election of directors and we will no longer be considered a controlled company.  As a result, we will be required to comply with NASDAQ Listing Rules 5605(d) and (e).

Risks Relating to the Combined Company

Uncertainties associated with the Acquisition or the combined company may cause delays in customer orders or even loss of customers, which could offset any benefits we may realize from the diversification of our customer base.

In response to the closing of the Acquisition, or due to the diversion of management’s attention, current and potential customers may delay or defer decisions concerning their use of our services.  In particular, prospective customers could be reluctant to purchase the combined company’s services due to uncertainty about the direction of the combined company.  To the extent that the Acquisition creates uncertainty among those persons and organizations contemplating purchases such that one large customer, or a significant group of smaller customers, delays, defers or changes purchases in connection with the Acquisition, our results of operations would be adversely affected.

There is no assurance that we will be able to continue or expand upon JCG’s past success in securing bids for new contracts.

JCG has maintained successful relationships with a wide range of customers.  There is no assurance that we will be able to replicate or improve upon JCG’s success in bidding on and securing projects for these and other customers following the Acquisition.  If we are unsuccessful at maintaining JCG’s relationships, we may not be able to achieve internal growth, expand our operations or grow our business and the failure to do so could have an adverse effect on the combined company’s financial condition, results of operations and cash flows.

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SPECIAL MEETING OF PRIMORIS STOCKHOLDERS

Date, Time and Place of Special Meeting

This proxy statement is being furnished in connection with the solicitation of proxies on behalf of our board of directors for use at a special meeting of our stockholders to be held on                     , 2010, at        A.M., Pacific Standard Time at              , or at any adjournments or postponements thereof.  If you need directions to the location of the special meeting in order to attend the meeting and vote in person, please contact us at (949) 598-9242.

Purpose of Special Meeting

The special meeting is being held to request that stockholders consider and vote upon two proposals:

·approval of the issuance of (a) 8,185,278 shares of common stock issuable upon the conversion of the Closing Shares and (b) up to 6,508,276 Earnout Shares; and

·approval of the conversion of the Closing Shares into 8,185,278 shares of common stock.

We do not expect a vote to be taken on any other matters at the special meeting.  If any other matters are properly presented at the special meeting for consideration, however, the holders of the proxies, if properly authorized, will have discretion to vote on these matters in accordance with their best judgment.

Record Date; Voting Information

The record date for the special meeting is                    , 2010.  If you were a common stockholder of record at the close of business on the record date, you are entitled to notice of, and to vote at, the special meeting and any adjournments thereof.  At the close of business on the record date,                       shares of our common stock were outstanding and entitled to vote.  Stockholders are entitled to one vote on each matter submitted to the stockholders for each share of our common stock held as of the record date.  The shares of Series A Preferred Stock issued to the Members in connection with the Acquisition do not have voting rights and therefore the holders of the Series A Preferred Stock are not entitled to vote at the special meeting.

Quorum

Shares entitled to vote at the special meeting may take action on a matter at the special meeting only if a quorum of those shares exists with respect to that matter.  The presence at the meeting, in person or when authorized, by means of remote communication or represented by proxy, of the holders a majority of the issued and outstanding shares of our common stock entitled to vote at the special meeting will constitute a quorum for the transaction of business at the special meeting.  As noted above, on the record date, there were                      shares of our common stock issued and outstanding.  As a result, the presence in person or by proxy of                     shares of our common stock will constitute a quorum for the transaction of business at the special meeting.

Required Votes

The proposal to approve of the issuance of (a) 8,185,278 shares of common stock issuable upon the conversion of the Closing Shares and (b) up to 6,508,276 Earnout Shares, must be approved by the affirmative vote of the majority of the shares present in person or represented by proxy and voting on the proposal.

The proposal to approve of the conversion of the Closing Shares into 8,185,278 shares of common stock must be approved by the affirmative vote of the majority of the shares present in person or represented by proxy and voting on the proposal.

Abstentions and Broker Non-Votes

Brokers, banks or other nominees who hold shares of our common stock for a beneficial owner have the discretion to vote on routine proposals when they have not received voting instructions from the beneficial owner of

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the shares prior to the special meeting.  A ���broker non-vote” occurs when a broker, bank or other nominee does not receive voting instructions from the beneficial owner and does not have the discretion to direct the voting of the shares.  Broker non-votes will be counted for purposes of calculating whether a quorum is present at the special meeting, but will not be counted for purposes of determining the number of votes present in person or represented by proxy and entitled to vote with respect to a particular proposal.  Thus, a broker non-vote will make a quorum more readily obtainable, but will not otherwise affect the outcome of the vote on a proposal that requires the approval of a majority of the votes present in person or represented by proxy and entitled to vote.  With respect to a proposal that requires the approval of a majority of the outstanding shares, a broker non-vote has the same effect as a vote AGAINST the proposal.  However, no such proposals are being voted on at the special meeting.  Abstentions will be considered present at the special meeting for the purpose of determining a quorum and will count as votes cast on the proposals.  An abstention on either proposal will have the same effect as a vote AGAINST the proposal.

Adjournment or Postponement

If a quorum is not present or represented at the special meeting, then either the chairperson of the special meeting or the stockholders holding a majority of the shares represented at the special meeting in person or by proxy have the power to cause the meeting to be adjourned, from time to time, without notice other than announcement at the meeting, until a quorum is present or represented by proxy.  At an adjourned meeting at which a quorum is present or represented by proxy, any business may be transacted which might have been transacted at the original special meeting.  If the adjournment is for more than 30 days, or if after the adjournment a new record date is fixed for the adjourned meeting, a notice of the adjourned meeting will be given to each stockholder of record entitled to vote at the adjourned meeting.

Recommendation of Primoris’ Board of Directors

Our board of directors unanimously recommends that you vote:

·FOR the approval of the issuance of (a) 8,185,278 shares of common stock issuable upon the conversion of the Closing Shares and (b) up to 6,508,276 Earnout Shares; and

·FOR the approval of the conversion of the Closing Shares into 8,185,278 shares of common stock.

Solicitation and Voting Procedures

You may vote by mail or by attending the special meeting in person and voting by ballot.  If you choose to vote by mail, simply mark your proxy card, date and sign it and return it to our transfer agent, Continental Stock Transfer & Trust Company, in the postage-paid envelope provided.

Submitting your completed proxy card will not limit your right to vote at the special meeting if you attend the special meeting and vote in person.  However, if your shares of common stock are held in the name of a broker, bank or other nominee, you must obtain a proxy, executed in your favor, from the holder of record to be able to vote at the special meeting.  You should allow yourself enough time prior to the special meeting to obtain this proxy from the holder of record.

The shares of common stock represented by the proxy cards received, properly marked, dated, signed and not revoked, will be voted at the special meeting.  If you sign and return your proxy card but do not give voting instructions, the shares of common stock represented by that proxy card will be voted as recommended by the board of directors.

We will pay the costs for the solicitation of proxies, including the cost of preparing and mailing this proxy statement.Proxy Statement. Proxies are being solicited primarily by mail, but the solicitation by mail may be followed-up by solicitation in person, or by telephone or facsimile, by our regular employees without additional compensation for such proxy solicitation activity. We will reimburse brokers, banks and other custodians and nominees for their reasonable out-of-pocket expenses incurred in sending proxy materials to our stockholders.

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