GIANT INDUSTRIES INC
SC 13E4, 1999-12-21
PETROLEUM REFINING
Previous: CNL INCOME FUND VIII LTD, 10-K405/A, 1999-12-21
Next: DREYFUS S&P 500 INDEX FUND, N-30D, 1999-12-21



<PAGE>   1

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                 SCHEDULE 13E-4
                         ISSUER TENDER OFFER STATEMENT
     (PURSUANT TO SECTION 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934)

                             GIANT INDUSTRIES, INC.
                                (NAME OF ISSUER)

                             GIANT INDUSTRIES, INC.
                      (NAME OF PERSON(S) FILING STATEMENT)

                          COMMON STOCK, $.01 PAR VALUE
                         (TITLE OF CLASS OF SECURITIES)

                                  374508 10 9
                     (CUSIP NUMBER OF CLASS OF SECURITIES)

                                JAMES E. ACRIDGE
                     CHIEF EXECUTIVE OFFICER AND PRESIDENT
                             GIANT INDUSTRIES, INC.
                          23733 NORTH SCOTTSDALE ROAD
                           SCOTTSDALE, ARIZONA 85255
                                 (480) 585-8888
                 (NAME, ADDRESS AND TELEPHONE NUMBER OF PERSON
              AUTHORIZED TO RECEIVE NOTICES AND COMMUNICATIONS ON
                   BEHALF OF THE PERSON(S) FILING STATEMENT)

                                   COPIES TO:

                            KAREN C. MCCONNELL, ESQ.
                             AUDREY V. DORCH, ESQ.
                             FENNEMORE CRAIG, P.C.
                     3003 NORTH CENTRAL AVENUE, SUITE 2600
                             PHOENIX, ARIZONA 85012
                                 (602) 916-5000

                               DECEMBER 21, 1999
     (DATE TENDER OFFER FIRST PUBLISHED, SENT OR GIVEN TO SECURITY HOLDERS)

                           CALCULATION OF FILING FEE

<TABLE>
<CAPTION>
TRANSACTION VALUATION                AMOUNT OF FILING FEE
- ---------------------                --------------------
<S>                                  <C>
     $12,000,000(1)                        $  2,400(2)
</TABLE>

- ---------------
(1) For the purpose of calculating the filing fee only, this amount is based on
    the purchase of 1,333,333 shares of common stock of Giant Industries, Inc.
    at $9.00 per share.

(2) The amount of the filing fee equals 1/50th of one percent of the value of
    the securities to be acquired.

[ ]  Check box if any part of the fee is offset as provided by Rule 0-11(a)(2)
and identify the filing with which the offsetting fee was previously paid.
Identify the previous filing by registration statement number, or the Form or
Schedule and the date of its filing.

<TABLE>
<S>                        <C>               <C>             <C>
AMOUNT PREVIOUSLY PAID:     Not applicable   FILING PARTY:   Not applicable.
FORM OR REGISTRATION NO.:   Not applicable   DATE FILED:     Not applicable.
</TABLE>

- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>   2

ITEM 1.  SECURITY AND ISSUER.

     (a) The issuer of the securities to which this statement relates is Giant
Industries, Inc., a Delaware corporation (the "Company"). The Company's
principal executive offices are located at 23733 North Scottsdale Road,
Scottsdale, Arizona 85255.

     (b) This Schedule 13E-4 relates to the offer by the Company to purchase up
to 1,333,333 shares of the Company's Common Stock, $.01 par value (the "Shares")
(or such lesser number of Shares as are properly tendered), at a price of $9.00
per Share, net to the seller in cash (the "Purchase Price"), upon the terms and
subject to the conditions set forth in the Offer to Purchase, dated December 21,
1999 (the "Offer to Purchase"), and in the related Letter of Transmittal (which,
as they may be amended and supplemented from time to time, are collectively
referred to herein as the "Offer"), copies of which are attached as Exhibits
(a)(1) and (a)(2), respectively, and incorporated herein by reference. As of
December 20, 1999, 10,303,488 of the Shares were outstanding, and 310,551 Shares
were issuable upon exercise of currently outstanding stock options. In the Offer
to Purchase, the Company reserved the right to purchase more than 1,333,333
Shares, but has no current intention of doing so. Reference is hereby made to
the Introduction and Section 1 of the Offer to Purchase, which Introduction and
Section 1 are incorporated by reference herein. The Offer to Purchase is being
made to all holders of Shares, including executive officers, directors and
affiliates of the Company. The Company has been advised that one of its
executive officers intends to tender Shares pursuant to the Offer. The
information set forth in Section 10, "Interest of Directors and Executive
Officers; Transactions and Arrangements Concerning Shares," of the Offer to
Purchase is incorporated herein by reference. The Company will not supplement or
amend the Offer if any directors or executive officers indicate a change in
their intention to tender Shares in the Offer.

     (c) The information set forth in Section 7, "Price Range of Shares;
Dividends," of the Offer to Purchase is incorporated by reference herein.

     (d) Not applicable.

ITEM 2.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

     (a) The information set forth in Section 8, "Source and Amount of Funds,"
of the Offer to Purchase is incorporated by reference herein.

     (b) Not applicable.

ITEM 3.  PURPOSE OF THE TENDER OFFER AND PLANS OR PROPOSALS OF THE ISSUER OR
AFFILIATE.

     (a)-(j) The information set forth in the Introduction and Section 2,
"Purpose of the Offer; Certain Effects of the Offer," of the Offer to Purchase
are incorporated by reference herein.

ITEM 4.  INTEREST IN SECURITIES OF THE ISSUER.

     The information set forth in Section 10, "Interest of Directors and
Executive Officers; Transactions and Arrangements Concerning Shares," of the
Offer to Purchase is incorporated herein by reference.

ITEM 5.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT
TO THE ISSUER'S SECURITIES.

     The information set forth in Section 10, "Interest of Directors and
Executive Officers; Transactions and Arrangements Concerning Shares," of the
Offer to Purchase is incorporated herein by reference.

ITEM 6.  PERSONS RETAINED, EMPLOYED OR TO BE COMPENSATED.

     The information set forth in the Introduction and Section 15, "Fees and
Expenses," of the Offer to Purchase are incorporated herein by reference.

                                        1
<PAGE>   3

ITEM 7.  FINANCIAL INFORMATION.

     (a)-(b) The information set forth in Section 9, "Certain Information
Concerning the Company," of the Offer to Purchase is incorporated herein by
reference.

ITEM 8.  ADDITIONAL INFORMATION.

     (a) Not applicable.

     (b) The information set forth in Section 12, "Certain Legal Matters;
Regulatory Approvals," of the Offer to Purchase is incorporated herein by
reference.

     (c) The information set forth in Section 11, "Effects of the Offer on the
Market for Shares; Registration under the Exchange Act," of the Offer to
Purchase is incorporated herein by reference.

     (d) Not applicable.

     (e) The information set forth in the Offer to Purchase and Letter of
Transmittal is incorporated herein by reference.

                                        2
<PAGE>   4

ITEM 9.  MATERIAL TO BE FILED AS EXHIBITS.

<TABLE>
<S>      <C>
(a)(1)   Form of Offer to Purchase, dated December 21, 1999.
(a)(2)   Form of Letter of Transmittal (including Certification of
         Taxpayer Identification Number on Form W-9).
(a)(3)   Form of Notice of Guaranteed Delivery.
(a)(4)   Form of Letter to Brokers, Dealers, Commercial Banks, Trust
         Companies and Other Nominees.
(a)(5)   Form of Letter to Clients for Use by Brokers, Dealers,
         Commercial Banks, Trust Companies and Other Nominees
         (including the Instruction Form).
(a)(6)   Form of Letter to Shareholders of the Company, dated
         December 21, 1999, from James E. Acridge, Chief Executive
         Officer and President of the Company.
(a)(7)   Guidelines for Certification of Taxpayer Identification
         Number on Substitute Form W-9.
(a)(8)   Form of Letter to Participants in the Company's employee
         stock ownership plan.
(a)(9)   Form of Letter to Participants in the Company's 401(k) plan
         whose accounts are invested in the Company's common stock
         fund.
(a)(10)  Text of Press Release issued by the Company, dated December
         21, 1999.
(b)      Not applicable.
(c)      Not applicable.
(d)      Not applicable.
(e)      Not applicable.
(f)      Not applicable.
</TABLE>

                                        3
<PAGE>   5

                                   SIGNATURE

     After due inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this Schedule 13E-4 is true, complete and
correct.

                                          GIANT INDUSTRIES, INC.

                                          By:     /s/ JAMES E. ACRIDGE
                                            ------------------------------------
                                                      James E. Acridge
                                                Chief Executive Officer and
                                                          President

                            Date: December 21, 1999

                                        4
<PAGE>   6

                               INDEX TO EXHIBITS

<TABLE>
<S>      <C>
(a)(1)   Form of Offer to Purchase, dated December 21, 1999.
(a)(2)   Form of Letter of Transmittal (including Certification of
         Taxpayer Identification Number on Form W-9).
(a)(3)   Form of Notice of Guaranteed Delivery.
(a)(4)   Form of Letter to Brokers, Dealers, Commercial Banks, Trust
         Companies and Other Nominees.
(a)(5)   Form of Letter to Clients for Use by Brokers, Dealers,
         Commercial Banks, Trust Companies and Other Nominees
         (including the Instruction Form).
(a)(6)   Form of Letter to Shareholders of the Company, dated
         December 21, 1999, from James E. Acridge, Chief Executive
         Officer and President of the Company.
(a)(7)   Guidelines for Certification of Taxpayer Identification
         Number on Substitute Form W-9.
(a)(8)   Form of Letter to Participants in the Company's employee
         stock ownership plan.
(a)(9)   Form of Letter to Participants in the Company's 401(k) plan
         whose accounts are invested in the Company's common stock
         fund.
(a)(10)  Text of Press Release issued by the Company, dated December
         21, 1999.
</TABLE>

<PAGE>   1

                                                                  EXHIBIT (A)(1)

                             GIANT INDUSTRIES, INC.

                        OFFER TO PURCHASE FOR CASH UP TO
                      1,333,333 SHARES OF ITS COMMON STOCK
                             AT A PURCHASE PRICE OF
                                $9.00 PER SHARE

     THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE AT 5:00 P.M.,
        EASTERN TIME, ON FEBRUARY 4, 2000, UNLESS THE OFFER IS EXTENDED.

     Giant Industries, Inc., a Delaware corporation (the "Company"), hereby
invites its shareholders to tender shares of its common stock, $.01 par value
(the "Shares"), to the Company at $9.00 per Share, net to the seller in cash
(the "Purchase Price"), upon the terms and subject to the conditions set forth
in this Offer to Purchase and in the related Letter of Transmittal (which, as
amended or supplemented from time to time, together constitute the "Offer"). The
Company will, upon the terms and subject to the conditions of the Offer, accept
for payment, and thereby purchase, up to 1,333,333 Shares validly tendered and
not withdrawn on or before 5:00 p.m., Eastern Time, on February 4, 2000 (the
"Expiration Date"). All Shares acquired in the Offer will be acquired at the
Purchase Price. The Company reserves the right, in its sole discretion, to
purchase more than 1,333,333 Shares pursuant to the Offer. See Sections 1 and
14. In the event more than 1,333,333 Shares are validly tendered and not
withdrawn on or before the Expiration Date, the Company will accept for payment,
and thereby purchase, Shares, other than Odd Lots (as defined in Section 1
hereof), on a pro rata basis upon the terms and subject to the conditions of the
Offer. See Section 1. Shares not purchased because of proration will be returned
at the Company's expense.

     THE OFFER IS NOT CONDITIONED ON ANY MINIMUM NUMBER OF SHARES BEING
TENDERED. THE OFFER IS, HOWEVER, SUBJECT TO CERTAIN OTHER CONDITIONS. SEE
SECTION 6.

     THE MEMBERS OF THE BOARD OF DIRECTORS OF THE COMPANY WHO MET TO APPROVE THE
OFFER UNANIMOUSLY APPROVED THE OFFER. NOTWITHSTANDING THE FOREGOING, NEITHER THE
COMPANY NOR ITS BOARD OF DIRECTORS MAKES ANY RECOMMENDATION TO ANY SHAREHOLDER
AS TO WHETHER TO TENDER OR REFRAIN FROM TENDERING HIS OR HER SHARES. EACH
SHAREHOLDER MUST INDIVIDUALLY MAKE THE DECISION WHETHER TO TENDER HIS OR HER
SHARES AND, IF SO, HOW MANY SHARES TO TENDER. EMPLOYEES, DIRECTORS, EXECUTIVE
OFFICERS AND AFFILIATES MAY PARTICIPATE IN THE OFFER ON THE SAME BASIS AS THE
COMPANY'S OTHER SHAREHOLDERS. THE COMPANY HAS BEEN ADVISED THAT ONE OF ITS
EXECUTIVE OFFICERS INTENDS TO TENDER SHARES PURSUANT TO THE OFFER. SEE SECTION
10.

     As of the close of business on December 20, 1999, the Company had issued
and outstanding 10,303,488 Shares, and 310,551 Shares were issuable upon
exercise of currently outstanding stock options. The 1,333,333 Shares that the
Company is offering to purchase pursuant to the Offer represent approximately
12.9% of the Shares issued and outstanding (approximately 12.6% assuming
exercise of currently outstanding options).

     The Shares are listed and principally traded on the New York Stock
Exchange, Inc. (the "NYSE") under the symbol "GI." On December 20, 1999, the
closing sales price per Share as reported on the NYSE was $7.00. SHAREHOLDERS
ARE URGED TO OBTAIN CURRENT MARKET QUOTATIONS FOR THE SHARES. See Section 7.

     Any shareholder desiring to tender all or any portion of his or her Shares
should either (i) complete and sign the Letter of Transmittal (or a facsimile
thereof) in accordance with the instructions in the Letter of Transmittal, mail
or deliver such Letter of Transmittal, together with any required signature
guarantee, and
<PAGE>   2

any other required documents to Harris Trust and Savings Bank (the
"Depositary"), and either mail or deliver the certificates representing such
tendered Shares to the Depositary (together with any other documents required by
the Letter of Transmittal) or tender such Shares pursuant to the procedure for
book-entry transfer set forth in Section 3 of the Offer, or (ii) request a
broker, dealer, commercial bank, trust company or other nominee to effect the
transaction for such shareholder. A shareholder whose Shares are registered in
the name of a broker, dealer, commercial bank, trust company or other nominee
must contact such person if he or she desires to tender such Shares. Any
shareholder who desires to tender Shares and whose certificates for such Shares
are not immediately available or cannot be delivered to the Depositary or who
cannot comply with the procedure for book-entry transfer or whose other required
documents cannot be delivered to the Depositary, in any case, by the Expiration
Date of the Offer must tender such Shares by following the procedure for
guaranteed delivery set forth in Section 3 of the Offer.

     Questions or requests for assistance or for additional copies of this Offer
to Purchase, the Letter of Transmittal, the Notice of Guaranteed Delivery or
other tender offer materials may be directed to the Information Agent at the
addresses and telephone numbers set forth on the back cover of this Offer to
Purchase. Additional copies of these materials will be furnished promptly at the
Company's expense. Shareholders may also contact their local broker, dealer,
commercial bank or trust company for assistance concerning the Offer.

     NO PERSON HAS BEEN AUTHORIZED TO MAKE ANY RECOMMENDATION ON BEHALF OF THE
COMPANY AS TO WHETHER SHAREHOLDERS SHOULD TENDER SHARES PURSUANT TO THE OFFER.
NO PERSON HAS BEEN AUTHORIZED TO GIVE ANY INFORMATION OR TO MAKE ANY
REPRESENTATIONS IN CONNECTION WITH THE OFFER OTHER THAN THOSE CONTAINED HEREIN
OR IN THE RELATED LETTER OF TRANSMITTAL. IF GIVEN OR MADE, SUCH RECOMMENDATION
AND SUCH OTHER INFORMATION AND REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING
BEEN AUTHORIZED BY THE COMPANY.

     TO VALIDLY TENDER SHARES, SHAREHOLDERS MUST PROPERLY COMPLETE, EXECUTE AND
DELIVER THE LETTER OF TRANSMITTAL. HOLDERS OR BENEFICIAL OWNERS OF SHARES UNDER
THE COMPANY'S EMPLOYEE STOCK OWNERSHIP PLAN OR 401(K) PLAN WHO WISH TO TENDER
ANY OF SUCH SHARES IN THE OFFER MUST FOLLOW THE SEPARATE INSTRUCTIONS AND
PROCEDURES DESCRIBED IN SECTION 3 OF THE OFFER TO PURCHASE.

     The date of this Offer to Purchase is December 21, 1999.

                                        2
<PAGE>   3

                                    SUMMARY

     This general summary is provided for the convenience of the Company's
shareholders and is qualified in its entirety by reference to the full text and
more specific details of this Offer to Purchase and the related Letter of
Transmittal.

Number of Shares to be
Purchased                        1,333,333 Shares (or such lesser number of
                                 Shares as are validly tendered and not
                                 withdrawn on or before the Expiration Date, as
                                 defined in Section 1).

Purchase Price                   $9.00 per Share, net to the seller in cash. All
                                 Shares acquired in the Offer will be acquired
                                 at the Purchase Price.

Conditions to the Offer          The Offer is subject to certain conditions. See
                                 Section 6.

How to Tender Shares             See Section 3. Call the Information Agent toll
                                 free at (877) 393-4959 or consult your broker
                                 for assistance.

Employee Stock Ownership Plan
  and 401(k) Plan                Holders or beneficial owners of Shares under
                                 the Company's employee stock ownership plan or
                                 401(k) plan who wish to tender any of such
                                 Shares in the Offer must follow the separate
                                 instructions and procedures described in
                                 Section 3.

Brokerage Commissions            Tendering shareholders who hold Shares in their
                                 own name and who tender their Shares directly
                                 to the Depositary will not be obligated to pay
                                 brokerage commissions. Shareholders holding
                                 Shares through brokers or banks are urged to
                                 consult the broker or bank to determine whether
                                 the transaction costs are applicable if
                                 shareholders tender their Shares through the
                                 brokers or banks and not directly to the
                                 Depositary.

Stock Transfer Tax               None, if payment is made to the registered
                                 holder.

Expiration and Proration Dates   February 4, 2000, at 5:00 p.m., Eastern Time,
                                 unless extended by the Company.

Payment Date                     As soon as practicable after the Expiration
                                 Date.

Position of the Company and
  its Board of Directors         Neither the Company nor its Board of Directors
                                 makes any recommendation to any shareholder as
                                 to whether to tender or refrain from tendering
                                 his or her Shares.

Withdrawal Rights                Tendered Shares may be withdrawn at any time
                                 until 5:00 p.m., Eastern Time, on February 4,
                                 2000, and, unless previously purchased, after
                                 5:00 p.m., Eastern Time, on February 17, 2000.
                                 See Section 4.

Proration                        In the event more than 1,333,333 Shares are
                                 validly tendered and not withdrawn on or before
                                 the Expiration Date, the Company will accept
                                 for payment, and thereby purchase Shares, other
                                 than Odd Lots, as defined in Section 1, on a
                                 pro rata basis.

Odd Lots                         There will be no proration of Shares tendered
                                 by any shareholder who owns beneficially fewer
                                 than 100 Shares (not including any Shares held
                                 pursuant to the Company's employee stock
                                 ownership plan or 401(k) plan) on December 20,
                                 1999, and on the Expiration Date, and who
                                 tenders all of such Shares prior to the
                                 Expiration Date and who checks the "Odd Lots"
                                 box in the Letter of Transmittal. See Section
                                 1.

Lost or Destroyed Certificates   Contact the Information Agent toll free at
                                 (877) 393-4959 immediately for assistance.
                                 Also, see Section 3 for instructions for
                                 tendering lost, destroyed or misplaced
                                 certificates.
                                        3
<PAGE>   4

                               TABLE OF CONTENTS

<TABLE>
<S>    <C>                                                           <C>
SUMMARY............................................................    3
INTRODUCTION.......................................................    5
THE OFFER..........................................................    6
 1.    Number of Shares; Proration.................................    6
 2.    Purpose of the Offer; Certain Effects of the Offer..........    8
 3.    Procedures for Tendering Shares.............................   10
 4.    Withdrawal Rights...........................................   14
 5.    Purchase of Shares and Payment of Purchase Price............   15
 6.    Certain Conditions of the Offer.............................   16
 7.    Price Range of Shares.......................................   17
 8.    Source and Amount of Funds..................................   18
 9.    Certain Information Concerning the Company..................   18
10.    Interest of Directors and Executive Officers; Transactions
         and Arrangements
         Concerning Shares.........................................   23
11.    Effects of the Offer on the Market for Shares; Registration
         Under the Exchange Act....................................   25
12.    Certain Legal Matters; Regulatory Approvals.................   25
13.    Certain United States Federal Income Tax Consequences.......   26
14.    Extension of the Offer; Termination; Amendment..............   29
15.    Fees and Expenses...........................................   30
16.    Additional Information......................................   30
17.    Miscellaneous...............................................   31
</TABLE>

                                        4
<PAGE>   5

TO THE HOLDERS OF SHARES OF COMMON STOCK OF
GIANT INDUSTRIES, INC.:

                                  INTRODUCTION

     Giant Industries, Inc., a Delaware corporation (the "Company"), hereby
invites its shareholders to tender shares of its common stock, $.01 par value
(the "Shares"), to the Company at $9.00 per Share, net to the seller in cash
(the "Purchase Price"), upon the terms and subject to the conditions set forth
in this Offer to Purchase and in the related Letter of Transmittal (which, as
amended or supplemented from time to time, together constitute the "Offer").

     The Company will, upon the terms and subject to the conditions of the
Offer, accept for payment, and thereby purchase up to 1,333,333 Shares validly
tendered and not withdrawn on or before the Expiration Date (as defined in
Section 1). All Shares acquired in the Offer will be acquired at the Purchase
Price. In the event more than 1,333,333 Shares are validly tendered and not
withdrawn on or before the Expiration Date, the Company will accept for payment,
and thereby purchase, Shares, other than Odd Lots (as defined in Section 1), on
a pro rata basis upon the terms and subject to the conditions of the Offer. See
Section 1. Shares not purchased because of proration will be returned at the
Company's expense to the shareholders who tendered such Shares. The Company
reserves the right, in its sole discretion, to purchase more than 1,333,333
Shares pursuant to the Offer. See Sections 1 and 14.

     THE OFFER IS NOT CONDITIONED ON ANY MINIMUM NUMBER OF SHARES BEING
TENDERED. THE OFFER IS, HOWEVER, SUBJECT TO CERTAIN OTHER CONDITIONS. SEE
SECTION 6.

     THE MEMBERS OF THE BOARD OF DIRECTORS OF THE COMPANY WHO MET TO APPROVE THE
OFFER UNANIMOUSLY APPROVED THE OFFER. NOTWITHSTANDING THE FOREGOING, NEITHER THE
COMPANY NOR ITS BOARD OF DIRECTORS MAKES ANY RECOMMENDATION TO ANY SHAREHOLDER
AS TO WHETHER TO TENDER OR REFRAIN FROM TENDERING HIS OR HER SHARES. EACH
SHAREHOLDER MUST INDIVIDUALLY MAKE THE DECISION WHETHER TO TENDER HIS OR HER
SHARES AND, IF SO, HOW MANY SHARES TO TENDER. EMPLOYEES, DIRECTORS, EXECUTIVE
OFFICERS AND AFFILIATES MAY PARTICIPATE IN THE OFFER ON THE SAME BASIS AS THE
COMPANY'S OTHER SHAREHOLDERS. THE COMPANY HAS BEEN ADVISED THAT ONE OF ITS
EXECUTIVE OFFICERS INTENDS TO TENDER SHARES PURSUANT TO THE OFFER. SEE SECTION
10.

     Upon the terms and subject to the conditions of the Offer, if at the
Expiration Date more than 1,333,333 Shares (or such greater number of Shares as
the Company may elect to purchase) are validly tendered and not withdrawn, the
Company will accept Shares first from all Odd Lot Holders (as defined in Section
1) who validly tender, and do not withdraw, all their Shares and then on a pro
rata basis from all other shareholders who validly tender, and do not withdraw,
Shares. See Section 1.

     The Purchase Price will be paid net to the tendering shareholder in cash
for all Shares purchased. Tendering shareholders who hold Shares in their own
name and who tender their Shares directly to the Depositary will not be
obligated to pay brokerage commissions, solicitation fees or, subject to
Instruction 6 of the Letter of Transmittal, stock transfer taxes on the purchase
of Shares by the Company pursuant to the Offer. Shareholders holding Shares
registered in the name of brokers or banks are urged to consult the brokers or
banks to determine whether transaction costs are applicable if shareholders
tender Shares through the brokers or banks and not directly to the Depositary.

     ANY TENDERING SHAREHOLDER OR OTHER PAYEE WHO FAILS TO COMPLETE, SIGN AND
RETURN TO THE DEPOSITARY THE SUBSTITUTE FORM W-9 INCLUDED AS PART OF THE LETTER
OF TRANSMITTAL MAY BE SUBJECT TO REQUIRED UNITED STATES FEDERAL INCOME TAX
BACK-UP WITHHOLDING EQUAL TO 31% OF THE GROSS

                                        5
<PAGE>   6

PROCEEDS PAYABLE TO THE TENDERING SHAREHOLDER OR OTHER PAYEE PURSUANT TO THE
OFFER. SEE SECTION 3.

     The Company will pay all fees and expenses of Corporate Investor
Communications, Inc. (the "Information Agent"), Harris Trust and Savings Bank
(the "Depositary"), Wells Fargo Bank, N.A. (the "ESOP Trustee") and its agent
and Fidelity Management Trust Company (the "401(k) Plan Trustee") and its agent,
incurred in connection with the Offer. See Section 15.

     The Offer provides shareholders who are considering a sale of all or a
portion of their Shares with the opportunity, subject to the terms and
conditions of the Offer, to sell those Shares for cash without, where Shares are
tendered by the registered owner thereof directly to the Depositary, the usual
transaction costs associated with open market sales. In addition, the Offer may
give shareholders the opportunity to sell at prices greater than market prices
prevailing prior to the announcement of the Offer. The Offer also allows
shareholders to sell a portion of their Shares while retaining a continuing
equity interest in the Company. Shareholders who determine not to accept the
Offer will realize a proportionate increase in their relative equity interest in
the Company, and thus in the Company's future earnings and assets (subject to
the Company's right to issue additional Shares and other equity securities in
the future). In determining whether to tender Shares pursuant to the Offer,
shareholders should consider the possibility that they may be able to sell their
Shares in the future on the NYSE or otherwise at a net price higher than the
Purchase Price. Shareholders should also consider the possibility that,
following completion of the Offer, they may not be able to sell their Shares in
the future on the NYSE or otherwise at a net price as high as the Purchase
Price. See Sections 2 and 11.

     As of the close of business on December 20, 1999, the Company had
10,303,488 issued and outstanding Shares and 310,551 Shares were issuable upon
exercise of currently outstanding stock options (the "Options") granted under
the Company's stock incentive plans (the "Plans"). See Section 10. The Company
is not, in connection with the Offer, offering to cancel for cash any Options
outstanding under the Plans and tenders of Options will not be accepted. See
Section 3.

     The 1,333,333 Shares that the Company is offering to purchase pursuant to
the Offer represent approximately 12.9% of the Shares outstanding on December
20, 1999 (approximately 12.6% assuming exercise of currently outstanding
Options). The Shares are listed on and share prices are reported by the New York
Stock Exchange, Inc. (the "NYSE") under the symbol "GI." On December 20, 1999,
the closing sales price per Share as reported on the NYSE was $7.00.
SHAREHOLDERS ARE URGED TO OBTAIN CURRENT MARKET QUOTATIONS FOR THE SHARES. See
Section 7.

                                   THE OFFER

1. NUMBER OF SHARES; PRORATION

     Upon the terms and subject to the conditions of the Offer, the Company will
purchase 1,333,333 Shares or such lesser number of Shares as are validly
tendered and not withdrawn on or before the Expiration Date (as defined below)
at a price of $9.00 per Share, net to the seller in cash.

     The term "Expiration Date" means 5:00 p.m., Eastern Time, on February 4,
2000, unless and until the Company, in its sole discretion, shall have extended
the period of time during which the Offer will remain open, in which event the
term "Expiration Date" shall refer to the latest time and date at which the
Offer, as so extended by the Company, shall expire. See Section 14 for a
description of the Company's right to extend, delay, terminate or amend the
Offer.

     The Company reserves the right, in its sole discretion, to purchase more
than 1,333,333 Shares pursuant to the Offer, but does not currently plan to do
so. In accordance with applicable regulations of the Securities and Exchange
Commission (the "Commission"), the Company may purchase, pursuant to the Offer,
an additional amount of Shares not to exceed 2% of the outstanding Shares
without amending or extending the Offer. See Section 14.

                                        6
<PAGE>   7

     THE OFFER IS NOT CONDITIONED ON THE TENDER OF ANY MINIMUM NUMBER OF SHARES.
THE OFFER IS, HOWEVER, SUBJECT TO CERTAIN OTHER CONDITIONS. SEE SECTION 6.

     If the number of Shares validly tendered and not withdrawn prior to the
Expiration Date is less than or equal to 1,333,333 Shares (or such greater
number of Shares as the Company may elect to purchase pursuant to the Offer),
the Company will, upon the terms and subject to the conditions of the Offer,
accept for payment and thereby purchase, all Shares so tendered at the Purchase
Price. In the event of an over-subscription of the Offer, Shares tendered prior
to the Expiration Date (other than Odd Lots) will be subject to proration, as
described below. The proration period also expires on the Expiration Date. All
Shares tendered and not purchased pursuant to the Offer, including Shares not
purchased because of proration, will be returned to the tendering shareholders
at the Company's expense as promptly as practicable following the Expiration
Date. The Company reserves the right, in its sole discretion to purchase more
than 1,333,333 Shares pursuant to the Offer, but does not currently plan to do
so. See Section 14.

  Priority of Purchases.

     Upon the terms and subject to the conditions of the Offer, if more than
1,333,333 Shares (or such greater number of Shares as the Company may elect to
purchase) have been validly tendered, and not withdrawn, prior to the Expiration
Date, the Company will accept for payment and therefore purchase validly
tendered Shares on the basis set forth below:

          (a) first, all Shares validly tendered and not withdrawn prior to the
     Expiration Date by any Odd Lot Holder (as defined below) who:

             (i) tenders all Shares owned beneficially or of record by such Odd
        Lot Holder (tenders of less than all the Shares owned by such Odd Lot
        Holder will not qualify for this preference); and

             (ii) completes the section entitled "Odd Lots" in the Letter of
        Transmittal and, if applicable, in the Notice of Guaranteed Delivery;
        and

          (b) second, after the purchase of all of the foregoing Shares, all
     other Shares validly tendered, and not withdrawn, prior to the Expiration
     Date, on a pro rata basis as described below.

  Odd Lots.

     For purposes of the Offer, the term "Odd Lots" means all Shares validly
tendered prior to the Expiration Date and not withdrawn by any person (an "Odd
Lot Holder") who owned beneficially or of record as of the close of business on
December 20, 1999, and who continues to own beneficially or of record as of the
Expiration Date, an aggregate of fewer than 100 Shares (not including any Shares
held pursuant to the Company's employee stock ownership plan or 401(k) plan) and
so certifies in the appropriate place on the Letter of Transmittal and, if
applicable, on the Notice of Guaranteed Delivery. In order to qualify for this
preference, an Odd Lot Holder must tender all Shares owned by the Odd Lot Holder
in accordance with the procedures described in Section 3. As set forth above,
Odd Lots will be accepted for payment before proration, if any, of the purchase
of other tendered Shares. This preference is not available to partial tenders by
an Odd Lot Holder, to beneficial or record holders of an aggregate of 100 or
more Shares, even if these holders have separate accounts or certificates
representing fewer than 100 Shares, or with respect to any Shares held pursuant
to the Company's employee stock ownership plan or 401(k) plan. Any Odd Lot
Holder wishing to tender all of such holder's Shares pursuant to the Offer must
complete the section entitled "Odd Lots" in the Letter of Transmittal and, if
applicable, in the Notice of Guaranteed Delivery.

  Proration.

     In the event that proration of tendered Shares is required, the Company
will determine the proration factor as soon as practicable following the
Expiration Date. Proration for each shareholder tendering Shares, other than Odd
Lot Holders, will be based on the ratio of the number of Shares validly tendered
and not properly withdrawn by such shareholder to the total number of Shares
validly tendered and not properly
                                        7
<PAGE>   8

withdrawn by all shareholders, other than Odd Lot Holders. Because of the
difficulty in determining the number of Shares validly tendered (including
Shares tendered by guaranteed delivery procedures, as described in Section 3)
and not properly withdrawn, and because of the Odd Lot procedure, the Company
does not expect that it will be able to announce the final proration factor or
commence payment for any Shares purchased pursuant to the Offer until
approximately seven (7) business days after the Expiration Date. The preliminary
results of any proration will be announced by press release as promptly as
practicable after the Expiration Date. Shareholders may obtain preliminary
proration information from the Information Agent and may be able to obtain such
information from their brokers.

     As described in Section 13, the number of Shares that the Company will
purchase from a shareholder pursuant to the Offer may affect the United States
federal income tax consequences to the shareholder of the purchase and,
therefore, may be relevant to a shareholder's decision whether or not to tender
Shares. Each shareholder should consult his or her own tax advisor as to the
particular federal income tax consequences to that shareholder of tendering
Shares pursuant to the Offer and the applicability and effect of any state,
local or foreign tax laws and recent changes in applicable tax laws.

     The Company expressly reserves the right, in its sole discretion, at any
time and from time to time, to extend the period of time during which the Offer
is open by giving oral or written notice of such extension to the Depositary and
making a public announcement thereof. See Section 14. There can be no assurance,
however, that the Company will exercise its right to extend the Offer.

     For purposes of the Offer, a "business day" means any day other than a
Saturday, Sunday or federal holiday and consists of the time period from 12:01
a.m. through 12:00 midnight, Eastern time. This Offer to Purchase and the
related Letter of Transmittal will be mailed to shareholders who were record
holders of Shares as of the close of business on December 20, 1999, and will be
furnished to brokers, banks and similar persons whose names, or the names of
whose nominees, appear on the Company's shareholder list or, if applicable, who
are listed as participants in a clearing agency's security position listing for
subsequent transmittal to beneficial owners of Shares.

2. PURPOSE OF THE OFFER; CERTAIN EFFECTS OF THE OFFER

     The Board of Directors has determined that the Company's financial
condition, outlook and current market conditions, including the recent trading
prices of Shares, make this an attractive time to repurchase outstanding Shares.
The Offer provides shareholders who are considering a sale of all or a portion
of their Shares with the opportunity, subject to the terms and conditions of the
Offer, to sell such Shares for cash without, where Shares are tendered by the
registered owner directly to the Depositary, the usual transaction costs
associated with open market sales. In addition, the Offer may give shareholders
the opportunity to sell at prices greater than market prices prevailing prior to
the announcement of the Offer. The Offer also allows shareholders to sell a
portion of their Shares while retaining a continuing equity interest in the
Company. Shareholders who determine not to accept the Offer will realize a
proportionate increase in their relative equity interest in the Company, and
thus in the Company's future earnings and assets, subject to the Company's right
to issue additional Shares and other equity securities in the future.
Shareholders may be able to sell non-tendered Shares in the future on the NYSE
or otherwise, including in connection with a sale of the Company, at a net price
higher than the Purchase Price. The Company can give no assurance, however, as
to the price at which a shareholder may be able to sell Shares in the future.
Shareholders should also consider the possibility that, following completion of
the Offer, they may not be able to sell their Shares in the future on the NYSE
or otherwise at a net price as high as the Purchase Price. See Section 11.

     The Company's strategy is to profitably operate its refining, retail
marketing and other marketing operations, to make selective acquisitions, and to
take advantage of growth opportunities within its existing operations. The
Company's immediate focus is to identify ways to reduce operating expenses and
non-essential capital expenditures, to sell non-strategic assets and
underperforming assets while maintaining the value and integrity of the
Company's core assets, and to explore additional ways to create greater value
for shareholders.

     The Board of Directors has in the past authorized the Company to repurchase
Shares in the open market and in private transactions. Since the inception of
the repurchase program in 1994, the Company has
                                        8
<PAGE>   9

repurchased 1,962,700 Shares for an aggregate cost of approximately $20.6
million. The Offer temporarily suspends the Company's repurchases of Shares
previously authorized by the Board of Directors. The funds required to complete
the Offer and pay related expenses will be provided from cash and cash
equivalents. See Section 8.

     THE MEMBERS OF THE BOARD OF DIRECTORS OF THE COMPANY WHO MET TO APPROVE THE
OFFER UNANIMOUSLY APPROVED THE OFFER. NOTWITHSTANDING THE FOREGOING, NEITHER THE
COMPANY NOR ITS BOARD OF DIRECTORS MAKES ANY RECOMMENDATION TO SHAREHOLDERS AS
TO WHETHER TO TENDER OR REFRAIN FROM TENDERING THEIR SHARES AND NEITHER HAS
AUTHORIZED ANY PERSON TO MAKE ANY RECOMMENDATION. SHAREHOLDERS ARE URGED TO
EVALUATE CAREFULLY ALL INFORMATION IN THE OFFER, CONSULT WITH THEIR OWN
INVESTMENT AND TAX ADVISORS AND MAKE THEIR OWN DECISIONS WHETHER TO TENDER
SHARES AND, IF SO, HOW MANY SHARES TO TENDER. THE COMPANY HAS BEEN ADVISED THAT
ONE OF ITS EXECUTIVE OFFICERS INTENDS TO TENDER SHARES PURSUANT TO THE OFFER.
SEE SECTION 10.

     The Company may in the future purchase additional Shares on the open
market, in private transactions, through tender offers or otherwise, subject to
the approval of the Board of Directors. In particular, the Board of Directors
may repurchase Shares in the open market beginning after the expiration of the
period of ten (10) business days after the Expiration Date. Future purchases by
the Company may be on the same terms or on terms that are more or less favorable
to shareholders than the terms of the Offer. Rule 13e-4 under the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), prohibits the Company and
its affiliates from purchasing any Shares, other than pursuant to the Offer,
until at least ten (10) business days after the Expiration Date. Any possible
future purchases by the Company pursuant to this intention or otherwise will
depend on many factors, including the market price of the Shares, the results of
the Offer, the Company's business and financial position and general economic
and market conditions. Shares the Company acquires pursuant to the Offer will be
restored to the status of authorized and unissued Shares, or placed in the
Company's treasury, and will be available for the Company to issue without
further shareholder action (except as required by applicable law or the rules
applicable to companies with shares reported on the NYSE or any other securities
exchange on which the Shares may be listed) for purposes including, but not
limited to, the acquisition of other businesses, the raising of additional
capital for use in the Company's business and the satisfaction of obligations
under existing or future Company benefit plans. The Company has no current plans
for the issuance of Shares repurchased pursuant to the Offer by the Company.

     Except as disclosed in this Offer to Purchase, the Company currently has no
plans or proposals that relate to or would result in: (a) the acquisition by any
person of additional securities of the Company or the disposition of securities
of the Company; (b) an extraordinary corporate transaction, such as a merger,
reorganization, sale or transfer of a material amount of assets, or liquidation,
involving the Company or any of its subsidiaries; (c) any change in the present
Board of Directors or management of the Company; (d) any material change in the
present dividend rate or policy, or indebtedness or capitalization of the
Company; (e) any other material change in the Company's corporate structure or
business; (f) any change in the Company's Certificate of Incorporation or Bylaws
or other actions which may impede the acquisition of control of the Company by
any person; (g) a class of equity security of the Company being delisted from a
national securities exchange or ceasing to be authorized for quotation in an
inter-dealer quotation system of a registered national securities association;
(h) a class of equity security of the Company becoming eligible for termination
of registration pursuant to Section 12(g)(4) of the Exchange Act; or (i) the
suspension of the Company's obligation to file reports pursuant to Section 15(d)
of the Exchange Act.

     Notwithstanding the foregoing, the Company periodically examines its
capital structure. Although no formal plans to modify the Company's capital
structure currently exist, such plans may be made in the future.

     In connection with plans previously communicated to the Company, Monte N.
Swetnam (age 63), the Executive Vice President, Administration and Corporate
Affairs for the Company, and Guy W. Yates (age

                                        9
<PAGE>   10

59), the President of the Company's Refining Group, have plans to retire.
Although the exact dates have not been set, both have indicated that it will be
early in 2000.

3. PROCEDURES FOR TENDERING SHARES

     To tender Shares validly pursuant to the Offer, a properly completed and
duly executed Letter of Transmittal or facsimile thereof, together with any
required signature guarantees and any other documents required by the Letter of
Transmittal, must be received by the Depositary at its address set forth on the
back cover of this Offer to Purchase and either (i) certificates for the Shares
to be tendered must be received by the Depositary at such address, (ii) such
Shares must be delivered pursuant to the procedures for book-entry transfer
described below (and a confirmation of such delivery received by the
Depositary), or (iii) the tendering shareholder must comply with the guaranteed
delivery procedure described below, in each case on or before the Expiration
Date.

     ODD LOT HOLDERS WHO TENDER ALL SHARES MUST COMPLETE THE SECTION CAPTIONED
"ODD LOTS" IN THE LETTER OF TRANSMITTAL AND, IF APPLICABLE, IN THE NOTICE OF
GUARANTEED DELIVERY, TO QUALIFY FOR THE PREFERENTIAL TREATMENT AVAILABLE TO ODD
LOT HOLDERS AS SET FORTH IN SECTION 1.

     SHAREHOLDERS WHO HOLD SHARES THROUGH BROKERS OR BANKS ARE URGED TO CONSULT
THE BROKERS OR BANKS TO DETERMINE WHETHER TRANSACTION COSTS ARE APPLICABLE IF
SHAREHOLDERS TENDER SHARES THROUGH THE BROKERS OR BANKS AND NOT DIRECTLY TO THE
DEPOSITARY.

  Signature Guarantees and Method of Delivery.

     No signature guarantee is required if: (i) the Letter of Transmittal is
signed by the registered holder of the Shares (which term, for purposes of this
Section 3, shall include any participant in The Depository Trust Company (the
"Book-Entry Transfer Facility") whose name appears on a security position
listing as the owner of the Shares) tendered therewith and such holder has not
completed the box entitled "Special Payment Instructions" or the box entitled
"Special Delivery Instructions" on the Letter of Transmittal; or (ii) the Shares
are tendered for the account of a member firm of a registered national
securities exchange, a member of the National Association of Securities Dealers,
Inc., or a commercial bank, trust company, savings bank, savings and loan
association or credit union which has membership in an approved Signature
Guarantee Medallion Program (each of the foregoing constituting an "Eligible
Institution"). See Instruction 1 of the Letter of Transmittal. If a certificate
for Shares is registered in the name of a person other than the person executing
a Letter of Transmittal, or if payment is to be made, or Shares not purchased or
tendered are to be issued to a person other than the registered holder, then the
certificate must be endorsed or accompanied by an appropriate stock power, in
either case, signed exactly as the name of the registered holder appears on the
certificate, with the signature guaranteed by an Eligible Institution.

     In all cases, payment for Shares tendered and accepted for payment pursuant
to the Offer will be made only after timely receipt by the Depositary of
certificates for such Shares (or a timely confirmation of the book-entry
transfer of the Shares into the Depositary's account at the Book-Entry Transfer
Facility as described above), a properly completed and duly executed Letter of
Transmittal (or a manually signed facsimile thereof) or an Agent's Message (as
defined below) in the case of a book-entry transfer, and any other documents
required by the Letter of Transmittal.

     THE METHOD OF DELIVERY OF ALL DOCUMENTS, INCLUDING CERTIFICATES FOR SHARES,
THE LETTER OF TRANSMITTAL AND ANY OTHER REQUIRED DOCUMENTS, IS AT THE ELECTION
AND RISK OF THE TENDERING SHAREHOLDER. IF DELIVERY IS BY MAIL, THEN REGISTERED
MAIL WITH RETURN RECEIPT REQUESTED, PROPERLY INSURED, IS RECOMMENDED. SUFFICIENT
TIME SHOULD BE ALLOWED TO ASSURE TIMELY DELIVERY.

                                       10
<PAGE>   11

  Book-Entry Delivery.

     The Depositary will establish an account with respect to the Shares for
purposes of the Offer at the Book-Entry Transfer Facility within two (2)
business days after the date of this Offer to Purchase, and any financial
institution that is a participant in the Book-Entry Transfer Facility's system
may make delivery of the Shares by causing the Book-Entry Transfer Facility to
transfer such Shares into the Depositary's account in accordance with the
Book-Entry Transfer Facility's procedures for transfer. Although delivery of
Shares may be effected through a book-entry transfer into the Depositary's
account at the Book-Entry Transfer Facility, either (i) a properly completed and
duly executed Letter of Transmittal (or a manually signed facsimile thereof)
with any required signature guarantees, or an Agent's Message, in each case
together with any other required documents must, in any case, be transmitted to
and received by the Depositary at its address set forth on the back cover of
this Offer to Purchase prior to the Expiration Date, or (ii) the guaranteed
delivery procedure described below must be followed. The confirmation of a
book-entry transfer of Shares into the Depositary's account at the Book-Entry
Transfer Facility as described above is referred to herein as a "Book-Entry
Confirmation."

     The term "Agent's Message" means a message transmitted by the Book-Entry
Transfer Facility to, and received by, the Depositary and forming a part of a
Book-Entry Confirmation, which states that the Book-Entry Transfer Facility has
received an express acknowledgment from the participant in the Book-Entry
Transfer Facility tendering the Shares that such participant has received and
agrees to be bound by the terms of the Letter of Transmittal and that the
Company may enforce such agreement against the participant.

     DELIVERY OF THE LETTER OF TRANSMITTAL AND ANY OTHER REQUIRED DOCUMENTS TO
THE BOOK-ENTRY TRANSFER FACILITY DOES NOT CONSTITUTE DELIVERY TO THE DEPOSITARY
AND WILL NOT CONSTITUTE A VALID TENDER.

  United States Federal Income Tax Backup Withholding.

     Under the United States federal income tax backup withholding rules, unless
an exemption applies under the applicable law and regulations, 31% of the gross
proceeds payable to a shareholder or other payee pursuant to the Offer must be
withheld and remitted to the United States Internal Revenue Service (the "IRS"),
unless the shareholder or other payee provides its taxpayer identification
number (employer identification number or social security number) to the
Depositary (as payor) and certifies under penalties of perjury that such number
is correct. Therefore, each tendering shareholder should complete and sign the
Substitute Form W-9 included as part of the Letter of Transmittal so as to
provide the information and certification necessary to avoid backup withholding.
If withholding results in an overpayment of taxes, a refund may be obtained.
Certain "exempt recipients" (including, among others, all corporations and
certain foreign shareholders (as defined in Section 13 herein)) are not subject
to these backup withholding and information reporting requirements. For a
foreign shareholder to qualify as an exempt recipient, that shareholder must
submit an IRS Form W-8 or a Substitute Form W-8, signed under penalties of
perjury, attesting to that shareholder's exempt status. Such statements can be
obtained from the Depositary. See Instruction 11 of the Letter of Transmittal.

  Withholding for Foreign Shareholders.

     Even if a foreign shareholder has provided the required certification to
avoid backup withholding, the Depositary will withhold United States federal
income taxes equal to 30% of the gross payments payable to a foreign shareholder
or his agent unless the Depositary determines that a reduced rate of withholding
is available pursuant to a tax treaty or that an exemption from withholding is
applicable because the gross proceeds are effectively connected with the conduct
of a trade or business within the United States. To obtain a reduced rate of
withholding pursuant to a tax treaty, a foreign shareholder must deliver to the
Depositary before the payment a properly completed and executed IRS Form 1001.
To obtain an exemption from withholding on the grounds that the gross proceeds
paid pursuant to the Offer are effectively connected with the conduct of a trade
or business within the United States, a foreign shareholder must deliver to the
Depositary a properly completed and executed IRS Form 4224. The Depositary will
determine a shareholder's

                                       11
<PAGE>   12

status as a foreign shareholder and eligibility for a reduced rate of, or
exemption from, withholding by reference to any outstanding certificates or
statements concerning eligibility for a reduced rate of, or exemption from,
withholding (e.g., IRS Form 1001 or IRS Form 4224) unless facts and
circumstances indicate that such reliance is not warranted. A foreign
shareholder may be eligible to obtain a refund of all or a portion of any tax
withheld if such foreign shareholder meets those tests described in Section 13
that would characterize the exchange as a sale (as opposed to a dividend) or is
otherwise able to establish that no tax or a reduced amount of tax is due.

     NON-UNITED STATES HOLDERS ARE URGED TO CONSULT THEIR OWN TAX ADVISORS
REGARDING THE APPLICATION OF UNITED STATES FEDERAL INCOME TAX WITHHOLDING,
INCLUDING ELIGIBILITY FOR A WITHHOLDING TAX REDUCTION OR EXEMPTION, AND THE
REFUND PROCEDURE.

  Guaranteed Delivery.

     If a shareholder desires to tender Shares pursuant to the Offer and the
shareholder's Share certificates are not immediately available or cannot be
delivered to the Depositary prior to the Expiration Date (or the procedure for
book-entry transfer cannot be completed on a timely basis) or if time will not
permit all required documents to reach the Depositary prior to the Expiration
Date, the Shares may nevertheless be tendered, provided that all of the
following conditions are satisfied: (i) the tender is made by or through an
Eligible Institution; (ii) the Depositary receives by hand, mail, overnight
courier, telegram or facsimile transmission, on or prior to the Expiration Date,
a properly completed and duly executed Notice of Guaranteed Delivery in the form
the Company has provided with this Offer to Purchase, including (where required)
a signature guarantee by an Eligible Institution in the form set forth in such
Notice of Guaranteed Delivery; and (iii) the certificates for all tendered
Shares, in proper form for transfer (or confirmation of book-entry transfer of
such Shares into the Depositary's account at the Book-Entry Transfer Facility),
together with a properly completed and duly executed Letter of Transmittal (or a
manually signed facsimile thereof) and any required signature guarantees or
other documents required by the Letter of Transmittal, or an Agent's Message in
the case of a book-entry transfer, are received by the Depositary within three
(3) business days after the date of execution of the Notice of Guaranteed
Delivery.

  Return of Tendered Shares.

     If any tendered Shares are not purchased, or if less than all Shares
evidenced by a shareholder's certificates are tendered, certificates for
unpurchased Shares will be returned as promptly as practicable after the
expiration or termination of the Offer or, in the case of Shares tendered by
book-entry transfer at the Book-Entry Transfer Facility, the Shares will be
credited to the appropriate account maintained by the tendering shareholder at
the Book-Entry Transfer Facility, in each case without expense to the
shareholder.

  Employee Stock Ownership Plan and 401(k) Plan.

     The Employee Stock Ownership Plan and Trust of Giant Industries, Inc. and
Affiliated Companies (the "employee stock ownership plan" or "ESOP") owns Shares
that are allocated to accounts of ESOP participants (the "ESOP Shares"). The
Giant Industries, Inc. and Affiliated Companies 401(k) Plan and Trust (the
"401(k) Plan") owns Shares that are part of a Company stock fund (the "Stock
Fund") that is an investment option for 401(k) Plan accounts (the "401(k) Plan
Shares"), and that is reflected by units of the Stock Fund in a participant's
401(k) Plan account. A small portion of the funds in the Stock Fund is held in
cash or cash equivalents.

     ESOP participants may instruct Wells Fargo Bank, N.A, the trustee of the
ESOP (the "ESOP Trustee"), to tender the ESOP Shares that are allocated to their
respective accounts as of the date of the Offer by properly following the
instructions set forth in the materials on the YELLOW paper included herewith.

                                       12
<PAGE>   13

     Proceeds from the tender by ESOP participants will be allocated to the ESOP
account of the participant. The ESOP Trustee may subsequently use those proceeds
to purchase shares in the Company, as the purpose of the ESOP is to invest
primarily in common stock of the Company.

     401(k) Plan participants whose accounts are invested, in whole or in part,
in the Stock Fund, may instruct Fidelity Management Trust Company, the trustee
of the 401(k) Plan (the "401(k) Plan Trustee"), to tender the 401(k) Plan Shares
that reflect the participants' proportional share of the Stock Fund by properly
following the instructions set forth in the materials on the PINK paper included
herewith.

     Proceeds from the tender by 401(k) Plan participants will be allocated to
the 401(k) Plan account of the participant and invested in the Fidelity
Retirement Government Money Market Portfolio, unless and until the 401(k) Plan
participant directs otherwise.

     DELIVERY OF A LETTER OF TRANSMITTAL BY A PARTICIPANT IN THE COMPANY'S ESOP
OR 401(K) PLAN WITH RESPECT TO ANY SHARES CREDITED PURSUANT TO SUCH PLANS DOES
NOT CONSTITUTE PROPER TENDER OF SUCH SHARES. PROPER TENDER OF ANY SHARES
CREDITED PURSUANT TO THE COMPANY'S ESOP OR 401(K) PLAN CAN ONLY BE MADE BY THE
TRUSTEES OF THE PLANS.

  Company Option Plans.

     The Company is not offering, as part of the Offer, to cancel for cash any
Options outstanding under the Company's Plans, and tenders of Options will not
be accepted. Holders of Options who wish to participate in the Offer must
exercise their Options and purchase Shares subject to the Option and then tender
the Shares pursuant to the Offer; provided that, any exercise of an Option and
tender of Shares is in accordance with the terms of the Plans and the Options
and is in compliance with all applicable federal and state securities laws. In
no event are any Options to be delivered to the Depositary in connection with a
tender of Shares hereunder. An exercise of an Option cannot be revoked even if
Shares received upon the exercise and tendered in the Offer are not purchased in
the Offer for any reason.

 Determination of Validity; Rejection of Shares; Waiver of Defects; No
 Obligation to Give Notice of Defects.

     Questions as to the validity, form, eligibility (including time of receipt)
and acceptance for payment of any tender of Shares will be determined by the
Company in its reasonable judgment, and its determination shall be final and
binding on all parties. The Company reserves the absolute right to reject any or
all tenders of any Shares that it determines are not in proper form or the
acceptance for payment of or payment for which may, in the opinion of the
Company's counsel, be unlawful. The Company also reserves the absolute right to
waive any of the conditions of the Offer or any defect or irregularity in any
tender with respect to any particular Shares or any particular shareholder. The
Company's interpretation of the terms of the Offer will be final and binding on
all parties. No tender of Shares will be deemed to have been properly made until
all defects or irregularities have been cured by the tendering shareholder or
waived by the Company. None of the Company, the Information Agent, the
Depositary or any other person shall be obligated to give notice of any defects
or irregularities in tenders, nor shall any of them incur any liability for
failure to give any notice.

 Tendering Shareholder's Representation and Warranty; Company's Acceptance
 Constitutes an Agreement.

     A tender of Shares pursuant to any of the procedures described above will
constitute the tendering shareholder's acceptance of the terms and conditions of
the Offer, as well as the tendering shareholder's representation and warranty to
the Company that, among other things, (i) the shareholder has a "net long
position" (as defined in Rule 14e-4 promulgated by the Commission under the
Exchange Act) in the Shares or equivalent securities at least equal to the
Shares tendered within the meaning of Rule 14e-4, and (ii) the tender of Shares
complies with Rule 14e-4. It is a violation of Rule 14e-4 for a person, directly
or indirectly, to tender Shares for that person's own account unless, at the
time of tender and at the end of the proration period (including any extensions
thereof), the person so tendering both (i) has a net long position equal to or
greater
                                       13
<PAGE>   14

than the amount of (x) the Shares tendered or (y) other securities immediately
convertible into or exchangeable or exercisable for the Shares tendered (and
will acquire the Shares for tender by conversion, exchange or exercise), and
(ii) will deliver or cause to be delivered the Shares in accordance with the
terms of the Offer. Rule 14e-4 provides a similar restriction applicable to the
tender or guarantee of a tender on behalf of another person. The Company's
acceptance for payment of Shares tendered pursuant to the Offer will constitute
a binding agreement between the tendering shareholder and the Company upon the
terms and conditions of the Offer.

  Lost or Destroyed Certificates.

     Shareholders whose certificates for their Shares have been lost, stolen,
misplaced or destroyed must contact the Information Agent at (877) 393-4959 for
instructions as to documents which will be required to be submitted together
with the Letter of Transmittal in order to replace certificate(s) representing
the Shares. SUCH SHAREHOLDERS ARE ADVISED TO CONTACT THE DEPOSITARY IMMEDIATELY
TO PERMIT TIMELY PROCESSING OF SUCH DOCUMENTATION.

     CERTIFICATES FOR SHARES, TOGETHER WITH A PROPERLY COMPLETED LETTER OF
TRANSMITTAL AND ANY OTHER DOCUMENTS REQUIRED BY THE LETTER OF TRANSMITTAL, MUST
BE DELIVERED TO THE DEPOSITARY AND NOT TO THE COMPANY. ANY SUCH DOCUMENTS
DELIVERED TO THE COMPANY WILL NOT BE FORWARDED TO THE DEPOSITARY AND THEREFORE
WILL NOT BE DEEMED TO BE VALIDLY TENDERED.

4. WITHDRAWAL RIGHTS

     Except as otherwise provided in this Section 4, tenders of Shares pursuant
to the Offer are irrevocable. Shares tendered pursuant to the Offer may be
withdrawn at any time prior to the Expiration Date and, unless theretofore
accepted for payment by the Company pursuant to the Offer, may also be withdrawn
at any time after 5:00 p.m., Eastern Time, on February 17, 2000.

     For a withdrawal to be effective, a notice of withdrawal must be in written
form and transmitted by mail, overnight courier, hand-delivery, telegraph, telex
or facsimile and must be received in a timely manner by the Depositary at the
address set forth on the back cover of this Offer to Purchase. Any such notice
of withdrawal must specify the name of the tendering shareholder, the number of
Shares to be withdrawn and the name of the registered holder of such Shares. If
the certificates for Shares to be withdrawn have been delivered or otherwise
identified to the Depositary, then, prior to the release of such certificates,
the tendering shareholder must also submit the serial numbers shown on the
particular certificates for Shares to be withdrawn and the signature(s) on the
notice of withdrawal must be guaranteed by an Eligible Institution (except in
the case of Shares tendered for the account of an Eligible Institution). A
purported notice of withdrawal which lacks any of the required information will
not be effective withdrawal of a tender previously made. If Shares have been
tendered pursuant to the procedure for book-entry transfer set forth in Section
3, the notice of withdrawal also must specify the name and the number of the
account at the Book-Entry Transfer Facility to be credited with the withdrawn
Shares and must otherwise comply with the Book-Entry Transfer Facility's
procedures.

     PARTICIPANTS IN THE COMPANY'S ESOP OR 401(K) PLAN WHO WISH TO WITHDRAW
THEIR SHARES MUST FOLLOW THE SEPARATE INSTRUCTIONS AND PROCEDURES SET FORTH IN
THE MATERIALS ON THE YELLOW PAPER INCLUDED HEREWITH, WITH RESPECT TO
PARTICIPANTS IN THE ESOP, AND ON THE PINK PAPER INCLUDED HEREWITH, WITH RESPECT
TO PARTICIPANTS IN THE 401(K) PLAN.

     Withdrawals may not be rescinded and any Shares properly withdrawn will
thereafter be deemed not validly tendered for purposes of the Offer unless the
withdrawn Shares are validly re-tendered prior to the Expiration Date by
following one of the procedures described in Section 3.

     If the Company extends the Offer, is delayed in its purchase of Shares or
is unable to purchase Shares pursuant to the Offer for any reason, then, without
prejudice to the Company's rights under the Offer, the Depositary may, subject
to applicable law, retain tendered Shares on behalf of the Company, and such
Shares

                                       14
<PAGE>   15

may not be withdrawn except to the extent tendering shareholders are entitled to
withdrawal rights as described in this Section 4, subject to Rule 13e-4(f)(5)
under the Exchange Act, which provides the issuer making the tender offer shall
either pay the consideration offered, or return the tendered securities promptly
after termination or withdrawal of the tender offer. All questions as to the
form and validity (including time of receipt) of any notice of withdrawal will
be determined by the Company, in its sole discretion, which determination shall
be final and binding on all parties. None of the Company, the Information Agent,
the Depositary or any other person is or will be under any duty to give
notification of any defect or irregularity in any notice of withdrawal or incur
any liability for failure to give any such notification.

5. PURCHASE OF SHARES AND PAYMENT OF PURCHASE PRICE

     Upon the terms and subject to the conditions of the Offer, as promptly as
practicable following the Expiration Date, the Company will accept for payment
and thereby purchase Shares validly tendered, and not withdrawn, prior to the
Expiration Date at the Purchase Price. For purposes of the Offer, the Company
will be deemed to have accepted for payment, and therefore purchased, Shares
that are validly tendered and not withdrawn (subject to the proration provisions
of the Offer) only when and if it gives written notice to the Depositary of its
acceptance of the Shares for payment pursuant to the Offer. In all cases,
payment for Shares accepted for payment pursuant to the Offer will be made only
after timely receipt by the Depositary of certificates for such Shares (or of a
timely confirmation of a book-entry transfer of such Shares into the
Depositary's account at the Book-Entry Transfer Facility), a properly completed
and duly executed Letter of Transmittal or a manually signed copy thereof, with
any required signature guarantees, or, in the case of a book-entry delivery, an
Agent's Message, and any other required documents.

     Upon the terms and subject to the conditions of the Offer, promptly
following the Expiration Date, the Company will accept for payment and pay the
Purchase Price for 1,333,333 Shares (subject to increase or decrease as provided
in Section 14) validly tendered, or such lesser number of Shares as are validly
tendered and not withdrawn as permitted in Section 4.

     The Company will pay for Shares purchased pursuant to the Offer by
depositing the aggregate Purchase Price therefor with the Depositary, which will
act as agent for tendering shareholders for the purpose of receiving payment
from the Company and transmitting payment to the tendering shareholders. In the
event of proration, the Company will determine the proration factor and pay for
those tendered Shares accepted for payment as soon as practicable after the
Expiration Date. The Company does not, however, expect to be able to announce
the final results of any proration and commence payment for Shares purchased
until approximately seven (7) business days after the Expiration Date.
Certificates for all Shares tendered and not purchased due to proration will be
returned (or, in the case of Shares tendered by book-entry transfer, will be
credited to the account maintained with the Book-Entry Transfer Facility by the
participant therein who so delivered the Shares) to the tendering shareholder at
the Company's expense as promptly as practicable after the Expiration Date or
termination of the Offer without expense to the tendering shareholders. Under no
circumstances will interest on the Purchase Price be paid by the Company by
reason of any delay in making payment.

     Payment for Shares may be delayed if there is difficulty in determining the
number of Shares properly tendered or if proration is required. See Section 1.
In addition, if certain events occur, the Company may not be obligated to
purchase Shares pursuant to the Offer. See Section 6.

     The Company will pay all stock transfer taxes, if any, payable on the
transfer to it of Shares purchased pursuant to the Offer. If, however, payment
of the Purchase Price is to be made to, or (in the circumstances permitted by
the Offer) if unpurchased Shares are to be registered in the name of, any person
other than the registered holder, or if tendered certificates are registered in
the name of any person other than the person signing the Letter of Transmittal,
the amount of all stock transfer taxes, if any (whether imposed on the
registered holder or the other person), payable on account of the transfer to
the person will be deducted from the Purchase Price unless satisfactory evidence
of the payment of the stock transfer taxes, or exemption therefrom, is
submitted. See Instruction 6 of the Letter of Transmittal.

                                       15
<PAGE>   16

     ANY TENDERING SHAREHOLDER OR OTHER PAYEE WHO FAILS TO COMPLETE FULLY AND
SIGN THE SUBSTITUTE FORM W-9 INCLUDED IN THE LETTER OF TRANSMITTAL (OR, IN THE
CASE OF A FOREIGN INDIVIDUAL, A FORM W-8) MAY BE SUBJECT TO REQUIRED FEDERAL
INCOME TAX WITHHOLDING OF 31% OF THE GROSS PROCEEDS PAID TO SUCH SHAREHOLDER OR
OTHER PAYEE PURSUANT TO THE OFFER. SEE SECTION 3.

6. CERTAIN CONDITIONS OF THE OFFER

     Notwithstanding any other provision of the Offer, the Company will not be
required to accept for payment, purchase or pay for any Shares tendered, and may
terminate or amend the Offer or may postpone the acceptance for payment of, or
the purchase of and the payment for Shares tendered, subject to Rule 13e-4(f)
under the Exchange Act, if at any time on or after December 21, 1999, and prior
to the Expiration Date, any of the following events shall have occurred (or
shall have been determined by the Company to have occurred) that, in the
Company's reasonable judgment and regardless of the circumstances giving rise
thereto (including any action or omission to act by the Company), makes it
inadvisable to proceed with the Offer or with acceptance for payment:

          (a) there shall have been threatened, instituted or pending any action
     or proceeding by any government or governmental, regulatory or
     administrative agency, authority or tribunal or any other person, domestic
     or foreign, before any court, authority, agency or tribunal that directly
     or indirectly (i) challenges the making of the Offer or the acquisition of
     some or all of the Shares pursuant to the Offer or otherwise relates in any
     manner to the Offer, or (ii) in the Company's reasonable judgment, could
     materially and adversely affect the business, condition (financial or
     otherwise), income, operations or prospects of the Company and its
     subsidiaries, taken as a whole, or otherwise materially impair in any way
     the contemplated future conduct of the business of the Company or any of
     its subsidiaries or materially impair the contemplated benefits of the
     Offer to the Company;

          (b) there shall have been any action threatened, pending or taken, or
     approval withheld, or any statute, rule, regulation, judgment, order or
     injunction threatened, proposed, sought, promulgated, enacted, entered,
     amended, enforced or deemed to be applicable to the Offer or the Company or
     any of its subsidiaries, by any legislative body, court or any authority,
     agency or tribunal that, in the Company's reasonable judgment, would or
     might directly or indirectly (i) make the acceptance for payment of, or
     payment for, some or all of the Shares illegal or otherwise restrict or
     prohibit consummation of the Offer, (ii) delay or restrict the ability of
     the Company, or render the Company unable, to accept for payment or pay for
     some or all of the Shares, (iii) materially impair the contemplated
     benefits of the Offer to the Company, (iv) materially and adversely affect
     the business, condition (financial or other), income, operations or
     prospects of the Company and its subsidiaries, taken as a whole, or
     otherwise materially impair in any way the contemplated future conduct of
     the business of the Company or any of its subsidiaries, or (v) make it
     likely that the Shares would cease to qualify for being reported on the
     NYSE;

          (c) there shall have occurred (i) any general suspension of trading
     in, or limitation on prices for, securities on any national securities
     exchange or in the over-the-counter market, (ii) the declaration of a
     banking moratorium or any suspension of payments in respect of banks in the
     United States, (iii) the commencement of a war, armed hostilities or other
     international or national calamity directly or indirectly involving the
     United States, (iv) any limitation (whether or not mandatory) by any
     governmental, regulatory or administrative agency or authority on, or any
     event that, in the Company's reasonable judgment, might affect, the
     extension of credit by banks or other lending institutions in the United
     States, (v) any significant decrease in the market price of the Shares or
     any change in the general political, market, economic or financial
     conditions in the United States or abroad that could, in the reasonable
     judgment of the Company, have a material adverse effect on the Company's
     business, operations or prospects or the trading in the Shares, (vi) in the
     case of any of the foregoing existing at the time of the commencement of
     the Offer, a material acceleration or worsening thereof, or (vii) any
     decline in either the Dow Jones Industrial Average or the Standard and
     Poor's 500 Composite Price Index by an amount in excess of 10% measured
     from the close of business on December 21, 1999;
                                       16
<PAGE>   17

          (d) a tender or exchange offer for any or all of the Shares (other
     than the Offer), or any merger, business combination or other similar
     transaction with or involving the Company or any subsidiary, shall have
     been proposed, announced or made by any person or "group" (as that term is
     used in Section 13(d)(3) of the Exchange Act);

          (e) (i) any entity, person or "group" (as that term is used in Section
     13(d)(3) of the Exchange Act) shall have acquired or proposed to acquire
     beneficial ownership of more than 5% of the outstanding Shares (other than
     any such person, entity or group who has filed a Schedule 13D or Schedule
     13G with the Commission on or before December 21, 1999), (ii) any such
     entity, group or person who has filed a Schedule 13D or Schedule 13G with
     the Commission on or before the Expiration Date shall have acquired or
     proposed to acquire beneficial ownership of an additional 2% or more of the
     outstanding Shares, or (iii) any person, entity or group shall have filed a
     Notification and Report Form under the Hart-Scott-Rodino Antitrust
     Improvements Act of 1976, as amended, or made a public announcement
     reflecting an intent to acquire the Company or any of its subsidiaries or
     any of their respective assets or securities other than in connection with
     a transaction authorized by the Board of Directors; or

          (f) any change or changes shall have occurred or be threatened in the
     business, financial condition, assets, income, operations, prospects or
     stock ownership of the Company or its subsidiaries that, in the Company's
     reasonable judgment, is or may be material to the Company or its
     subsidiaries.

     The foregoing conditions are for the sole benefit of the Company and may be
asserted by the Company regardless of the circumstances (including any action or
omission by the Company) giving rise to any such condition, and may be waived by
the Company, in whole or in part, at any time and from time to time in its
reasonable judgment. The Company's failure at any time to exercise any of the
foregoing rights shall not be deemed a waiver of any such right and each such
right shall be deemed an ongoing right which may be asserted at any time and
from time to time. Any determination by the Company concerning the events
described above will be final and binding. The Exchange Act requires that all
conditions to the Offer must be satisfied or waived before the Expiration Date.

7. PRICE RANGE OF SHARES

     The Shares are listed on the NYSE under the symbol "GI." The following
table sets forth, for the fiscal quarters indicated, the high and low closing
per Share sales prices as reported on the NYSE Composite Tape and as compiled
from published financial sources in each of such fiscal quarters, and the
dividends declared for such fiscal quarters.

<TABLE>
<CAPTION>
                                                                HIGH        LOW
                                                              --------    --------
<S>                                                           <C>         <C>
Fiscal Year 1997
1st Quarter.................................................  $15.625     $12.375
  2nd Quarter...............................................   16.875      10.00
  3rd Quarter...............................................   20.625      15.00
  4th Quarter...............................................   20.50       16.75
Fiscal Year 1998
  1st Quarter...............................................  $21.0625    $16.75
  2nd Quarter...............................................   23.6875     17.3125
  3rd Quarter...............................................   18.5625     10.75
  4th Quarter...............................................   13.50        8.5625
Fiscal Year 1999
  1st Quarter...............................................  $ 9.8125    $ 5.625
  2nd Quarter...............................................   12.25        7.6875
  3rd Quarter...............................................   12.5625      9.25
Fourth Quarter Through December 20, 1999....................   11.6875      6.8125
</TABLE>

                                       17
<PAGE>   18

     On December 20, 1999, the closing per Share sales price as reported on the
NYSE was $7.00. SHAREHOLDERS ARE URGED TO OBTAIN CURRENT MARKET QUOTATIONS FOR
THE SHARES.

8. SOURCE AND AMOUNT OF FUNDS

     Assuming the Company purchases 1,333,333 Shares pursuant to the Offer at
the Purchase Price, the Company expects the aggregate cost, including all fees
and expenses applicable to the Offer, to be approximately $12.2 million. The
Company expects to fund the purchase of Shares pursuant to the Offer and the
payment of related fees and expenses from available cash and cash equivalents.

9. CERTAIN INFORMATION CONCERNING THE COMPANY

  General.

     Giant Industries, Inc., a Delaware corporation (the "Company"), through its
wholly-owned subsidiary Giant Industries Arizona, Inc. ("Giant Arizona"), is
engaged in the refining and marketing of petroleum products in New Mexico,
Arizona, Colorado and Utah, with a concentration in the Four Corners where these
states adjoin. In addition, Phoenix Fuel Co., Inc. ("Phoenix Fuel"), a
wholly-owned subsidiary of Giant Arizona, operates an industrial/commercial
petroleum fuels and lubricants distribution operation.

     The Company currently has three strategic business units, the Refining
Group, the Retail Group and Phoenix Fuel.

     The Refining Group consists of the Company's two refineries, its fleet of
crude oil and finished product truck transports, its crude oil pipeline
gathering operations and its finished product terminaling operations. The
Company's two refineries manufacture various grades of gasoline, diesel fuel,
jet fuel and other products from crude oil, other feedstocks and blending
components. These products are sold through Company-operated retail facilities,
independent wholesalers and retailers, industrial/commercial accounts and sales
and exchanges with major oil companies. Crude oil, other feedstocks and blending
components are purchased from third party suppliers.

     The Retail Group consists of service station/convenience stores and one
travel center. These operations sell various grades of gasoline, diesel fuel,
general merchandise and food products to the general public through retail
locations. The petroleum fuels sold by the Retail Group are supplied by the
Refining Group, which either manufactures these refined products or acquires
them through exchange arrangements, third party purchases, or from Phoenix Fuel.
General merchandise and food products are obtained from third party suppliers.

     Phoenix Fuel is an industrial/commercial petroleum fuels and lubricants
distribution operation, which includes a number of bulk distribution plants, an
unattended fleet fueling ("cardlock") operation and a fleet of finished product
truck transports. The petroleum fuels and lubricants sold are primarily obtained
from third party suppliers and to a lesser extent from the Refining Group.

     The Company was incorporated in 1989 in connection with the concurrent
initial public offering of common stock by the Company and the reorganization of
Giant Arizona and Hixon Development Company.

     The Company's principal executive office is located at 23733 North
Scottsdale Road, Scottsdale, Arizona 85255.

                                       18
<PAGE>   19

  SUMMARY HISTORICAL CONSOLIDATED FINANCIAL INFORMATION SUMMARY UNAUDITED PRO
                    FORMA CONSOLIDATED FINANCIAL INFORMATION

     The following summary of historical condensed consolidated financial data
for the years ended December 31, 1997 and 1998, has been derived from the
audited consolidated financial statements of the Company. The following summary
historical condensed consolidated financial data for the nine months ended
September 30, 1998 and 1999, has been derived from the unaudited consolidated
financial statements of the Company and, in the opinion of management, include
all adjustments (consisting of normal recurring adjustments) necessary for a
fair presentation of the financial position and results of operations for such
periods. The data should be read in conjunction with the consolidated financial
statements and notes thereto included in the Company's Quarterly Report on Form
10-Q for the quarter ended September 30, 1999 and the Company's Annual Report on
Form 10-K for the year ended December 31, 1998, which are incorporated herein by
reference. More comprehensive financial information is included in such reports
and the financial information which follows is qualified in its entirety by
reference to such reports and all of the financial statements and related notes
contained therein, copies of which may be obtained as described in Section 16 of
this Offer.

     The Company's strategic business units have historically been affected by a
number of competitive factors. In addition, the Company's earnings are cyclical
in nature. The Company anticipates that its 1999 fourth quarter earnings will be
significantly lower than its 1999 third quarter earnings, due primarily to
increases in crude oil prices and reduced refinery sourced sales of petroleum
products. The Company does, however, expect that the results for the fourth
quarter of 1999 will be better than the results for the same period in 1998.

     The following summary of unaudited pro forma condensed consolidated
financial data has been derived from the historical consolidated financial
statements of the Company adjusted for certain costs and expenses to be incurred
as a result of the purchase of Shares pursuant to the Offer. The summary
unaudited pro forma condensed consolidated financial data should be read in
conjunction with the summary historical consolidated financial data included
herein. The pro forma condensed income statement data and condensed balance
sheet data are not necessarily indicative of the financial position or results
of operations that would have been obtained had the Offer been completed as of
the dates indicated.

                                       19
<PAGE>   20

                    GIANT INDUSTRIES, INC. AND SUBSIDIARIES

             SUMMARY HISTORICAL CONSOLIDATED FINANCIAL INFORMATION
                (IN THOUSANDS EXCEPT SHARES AND PER SHARE DATA)

<TABLE>
<CAPTION>
                                                                               NINE MONTHS ENDED
                                                  YEAR ENDED DECEMBER 31,        SEPTEMBER 30,
                                                  ------------------------    --------------------
                                                     1997          1998         1998        1999
                                                  ----------    ----------    --------    --------
<S>                                               <C>           <C>           <C>         <C>
EARNINGS STATEMENT INFORMATION:
Net revenues....................................   $657,278      $642,504     $470,191    $564,706
Net earnings (loss).............................     15,294        (2,217)        (502)     11,728
Net earnings (loss) per common share:
  Basic.........................................   $   1.38      $  (0.20)    $  (0.05)   $   1.09
  Assuming dilution.............................   $   1.37      $  (0.20)    $  (0.05)   $   1.08

BALANCE SHEET INFORMATION:
  Cash and cash equivalents.....................   $ 82,592      $ 55,697     $ 14,562    $ 30,608
  Working capital...............................    111,725        91,104       33,785      66,092
  Total assets..................................    535,371       525,785      525,865     545,060
  Total assets, net of goodwill.................    517,008       502,883      503,029     522,975
  Long-term debt, including current portion.....    276,119       283,684      264,810     258,739
  Common stockholders' equity...................    133,467       127,702      130,137     134,575

OTHER FINANCIAL INFORMATION:
  Ratio of earnings to fixed charges(1).........       2.24          0.87         0.94        1.88
  Book value per share..........................   $  12.14      $  11.78     $  11.94    $  12.90
</TABLE>

                                       20
<PAGE>   21

                    GIANT INDUSTRIES, INC. AND SUBSIDIARIES

              PRO FORMA SUMMARY CONSOLIDATED FINANCIAL INFORMATION
                (IN THOUSANDS EXCEPT SHARES AND PER SHARE DATA)

<TABLE>
<CAPTION>
                                                             YEAR ENDED DECEMBER 31, 1998
                                                       ----------------------------------------
                                                                      PRO FORMA
                                                       HISTORICAL    ADJUSTMENTS      PRO FORMA
                                                       ----------    -----------      ---------
<S>                                                    <C>           <C>              <C>
EARNINGS STATEMENT INFORMATION:
Net revenues.........................................  $  642,504                     $ 642,504
  Net earnings (loss)................................      (2,217)          (340)(2)     (2,557)
  Net earnings (loss) per common share:
     Basic...........................................  $    (0.20)                    $   (0.27)
     Assuming dilution...............................  $    (0.20)                    $   (0.27)
BALANCE SHEET INFORMATION:
  Cash and cash equivalents..........................  $   55,697    $   (12,507)(3)  $  43,190
  Working capital....................................      91,104        (12,507)(3)     78,597
  Total assets.......................................     525,785        (12,507)(3)    513,278
  Total assets, net of goodwill......................     502,883        (12,507)(3)    490,376
  Long-term debt, including current portion..........     283,684                       283,684
  Common stockholders' equity........................     127,702        (12,507)(3)    115,195
OTHER FINANCIAL INFORMATION:
  Ratio of earnings to fixed charges(1)..............        0.87                          0.85
  Book value per share...............................  $    11.78                     $   12.12
  Weighted average number of shares
     outstanding -- basic............................  10,950,991     (1,333,333)(4)  9,617,658
  Weighted average number of shares outstanding --
     assuming dilution...............................  10,950,991     (1,333,333)(4)  9,617,658
</TABLE>

                                       21
<PAGE>   22

                    GIANT INDUSTRIES, INC. AND SUBSIDIARIES

              PRO FORMA SUMMARY CONSOLIDATED FINANCIAL INFORMATION
                (IN THOUSANDS EXCEPT SHARES AND PER SHARE DATA)

<TABLE>
<CAPTION>
                                                          NINE MONTHS ENDED SEPTEMBER 30, 1999
                                                         ---------------------------------------
                                                                        PRO FORMA
                                                         HISTORICAL    ADJUSTMENTS     PRO FORMA
                                                         ----------    -----------     ---------
<S>                                                      <C>           <C>             <C>
EARNINGS STATEMENT INFORMATION:
Net revenues...........................................  $  564,706                    $ 564,706
  Net earnings (loss)..................................      11,728          (255)(2)     11,473
  Net earnings (loss) per common share:
     Basic.............................................  $     1.09                    $    1.21
     Assuming dilution.................................  $     1.08                    $    1.21
BALANCE SHEET INFORMATION:
  Cash and cash equivalents............................  $   30,608    $  (12,422)(3)  $  18,186
  Working capital......................................      66,092       (12,422)(3)     53,670
  Total assets.........................................     545,060       (12,422)(3)    532,638
  Total assets, net of goodwill........................     522,975       (12,422)(3)    510,553
  Long-term debt, including current portion............     258,739                      258,739
  Common stockholders' equity..........................     134,575       (12,422)(3)    122,153
OTHER FINANCIAL INFORMATION:
  Ratio of earnings to fixed charges(1)................        1.88                         1.86
  Book value per share.................................  $    12.90                    $   13.42
  Weighted average number of shares
     outstanding -- basic..............................  10,784,444    (1,333,333)(4)  9,451,111
  Weighted average number of shares
     outstanding -- assuming dilution..................  10,830,844    (1,333,333)(4)  9,497,511
</TABLE>

- ---------------
NOTES TO SUMMARY CONSOLIDATED FINANCIAL INFORMATION:

(1) The ratio of earnings to fixed charges is computed by dividing (i) earnings
    before income taxes plus fixed charges by (ii) fixed charges. Fixed charges
    consist of interest on indebtedness, amortization of debt issue costs,
    capitalized interest and the estimated interest component (one-third) of
    rental and lease expense. Earnings before income taxes did not cover fixed
    charges by $3,726 and $1,244 in the historical periods ended 12/31/98 and
    9/30/98, respectively. The earnings shortfall to cover fixed charges for the
    pro forma period ended 12/31/98 was $4,292.

(2) Represents the adjustment for the elimination of interest income earned on
    cash equivalents used to purchase the stock, net of income tax at the rate
    of 40%. The interest rate used to calculate interest income was
    approximately 4.72%.

(3) Represents the cost of the Shares purchased, including estimated transaction
    costs of approximately $167,000 incurred in connection with the Offer, and
    the elimination of interest income earned on cash equivalents used to
    purchase the Shares, net of income tax.

(4) Represents the number of Shares to be acquired under the Offer.

                                       22
<PAGE>   23

10. INTEREST OF DIRECTORS AND EXECUTIVE OFFICERS; TRANSACTIONS AND ARRANGEMENTS
    CONCERNING SHARES

     As of the close of business on December 20, 1999, the Company had
10,303,488 Shares issued and outstanding, and 310,551 Shares were issuable upon
exercise of currently outstanding Options. The 1,333,333 Shares that the Company
is offering to purchase pursuant to the Offer represent approximately 12.9% of
the Shares outstanding on December 20, 1999 (approximately 12.6% assuming
exercise of currently outstanding Options.) As of December 20, 1999, the
Company's directors and executive officers as a group (14 persons) beneficially
owned an aggregate of 2,316,056 Shares (including 163,968 Shares covered by
outstanding Options exercisable within 60 days of December 20, 1999),
representing approximately 22.13% of the outstanding Shares, assuming the
exercise by such persons of Options that are currently exercisable or that are
exercisable within such 60 day period.

     Except as set forth below, neither the Company nor, to the best of the
Company's knowledge, any of the Company's directors or executive officers, nor
any affiliates of any of the foregoing, has had any transactions involving the
Shares during the 40 business days prior to the date hereof. On December 9,
1999, 172,055 ESOP Shares were distributed to Mr. Acridge in accordance with the
terms of the ESOP. On December 16 and 17, 1999, James E. Acridge, the Chairman,
President and Chief Executive Officer of the Company, pledged 50,000 and 30,000
Shares, respectively, as security for loans, the proceeds of which were used for
general purposes and not to finance the acquisition of Shares. Mr. Acridge
retains the right to direct the voting and disposition of such Shares and the
right to receive all dividends, subject to standard default provisions.

     Executive officers and directors of the Company may participate in the
Offer on the same basis as the Company's other shareholders. The Company has
been advised that one of its executive officers intends to participate in the
Offer. Guy W. Yates, the President of the Company's Refining Group, intends to
tender approximately 13,500 Shares in the Offer.

     The table below identifies each executive officer and director of the
Company and sets forth, as of December 20, 1999, the number of Shares
beneficially owned by each of the directors and executive officers of the
Company and all directors and executive officers as a group (including Options
exercisable within 60 days of December 20, 1999) and the percent of Shares
currently beneficially owned to the total number of Shares outstanding. All
information with respect to beneficial ownership has been furnished by the
respective director or executive officer, as the case may be.

                                       23
<PAGE>   24

<TABLE>
<CAPTION>
                                      OPTIONS WITHIN
                                        60 DAYS OF                                TOTAL OF
                          COMMON       DECEMBER 20,                                 CLASS
NAME                       STOCK           1999         ESOP(1)    401(K) PLAN      OWNED      PERCENT
- ----                     ---------    --------------    -------    -----------    ---------    -------
<S>                      <C>          <C>               <C>        <C>            <C>          <C>
James E. Acridge.......  2,055,983(2)     86,801             0(3)       *         2,142,784     20.62
Fredric L. Holliger....     23,927(4)     22,000         6,860          *            52,787        **
Monte N. Swetnam.......          0         5,000           904          *             5,904        **
Morgan Gust............        500        25,000         4,070          *            29,570        **
Gary R. Dalke..........          0             0            19          *                19        **
Mark B. Cox............          0             0           134          *               134        **
Kim H. Bullerdick......      2,115         5,000         7,212          *            14,327        **
Jack Keller............          0             0            19          *                17        **
Philip W. Tomczyk......          0         6,667             0          *             6,667        **
Guy W. Yates...........          0        13,500         5,545          *            19,045        **
Anthony J. Bernitsky...     30,000(5)          0(6)          0(6)       *            30,000        **
F. Michael Geddes......     10,200             0(6)          0(6)       *            10,200        **
Harry S. Howard, Jr....      4,500(7)          0(6)          0(6)       *             4,500        **
Richard T. Kalen,
  Jr...................        100             0(6)          0(6)       *               100        **
Executive Officers and
  Directors as a
  Group................  2,127,325       163,968        24,763          *         2,316,056     22.13
</TABLE>

- ---------------
  * None of the aforementioned executive officers or directors beneficially owns
    any Shares under the 401(k) Plan.

 ** Less than 1%.

(1) Shares allocated to the individual's ESOP account as of December 31, 1998,
    the most recent date for which information as to individual allocations is
    available.

(2) Mr. Acridge has pledged 1,958,922 Shares to various lenders as security for
    loans, the proceeds of which were used for general purposes and not to
    finance the acquisition of Shares. Certain of Mr. Acridge's loans are margin
    loans that are subject to call from time to time. Mr. Acridge retains the
    right to direct the voting and disposition of such Shares and the right to
    receive all dividends, subject to standard default provisions.

    In connection with a loan to Mr. Acridge made by Lanty L. Smith that is
    secured by 144,040 of the 1,958,922 total Shares pledged to various
    lenders, Mr. Acridge also granted a purchase option to Mr. Smith for the
    144,040 pledged Shares at a price of $10.625 per share. Such option may be
    exercised at any time after the earliest of (i) November 22, 1999; (ii) the
    execution by the Company of a letter of intent, agreement or other document
    with respect to a transaction or series of transactions relating to a
    corporate reorganization or other fundamental event that would lead to the
    delisting of the capital stock of the Company on the New York Stock
    Exchange; or (iii) the occurrence of an event of default under the stock
    pledge agreement related to the loan from Mr. Smith to Mr. Acridge. In
    addition, if at any time Mr. Acridge tenders payment in full of all
    principal and accrued but unpaid interest under the loan, Mr. Smith has
    five (5) business days to elect, in his sole discretion, to either (i)
    accept such payment and surrender his rights under the option, or (ii)
    exercise the option as an offset of the amounts due under the loan. If the
    option is not exercised within such five-day period, it expires. Unless the
    option expires earlier in connection with the repayment of the loan by Mr.
    Acridge, the option expires on November 22, 2000.

    In addition, Mr. Smith is the Chairman, and a principal of, Soles Brower
    Smith & Co. ("SBS"), a financial advisor retained by the Company. In
    connection with that arrangement, SBS has provided advice to the Company in
    connection with the Offer.

(3) As of December 31, 1998, Mr. Acridge had 172,055 Shares allocated to his
    ESOP account. Such Shares were distributed to Mr. Acridge on December 9,
    1999, in accordance with the terms of the ESOP.

(4) Includes 1,000 Shares owned by Mr. Holliger's minor child as to which Mr.
    Holliger disclaims beneficial ownership.

                                       24
<PAGE>   25

(5) Shares are held in a living trust where Mr. Bernitsky and his spouse are
    settlors, co-trustees and beneficiaries.

(6) Non-employee directors are not eligible to participate in the Company's
    stock incentive plans or the ESOP.

(7) Shares are held in a living trust where Mr. Howard and his spouse are
    settlors, co-trustees and beneficiaries.

     Except for outstanding Options to purchase Shares granted to certain
employees (including directors and executive officers), and as otherwise
described herein, neither the Company nor, to the best of the Company's
knowledge, any of its affiliates, directors or executive officers, is a party to
any contract, arrangement, understanding or relationship with any other person
relating, directly or indirectly, to the Offer with respect to any securities of
the Company, including, but not limited to, any contract, arrangement,
understanding or relationship concerning the transfer or the voting of any such
securities, joint ventures, loan or option arrangements, puts or calls,
guarantees of loans, guarantees against loss or the giving or withholding of
proxies, consents or authorizations.

11. EFFECTS OF THE OFFER ON THE MARKET FOR SHARES; REGISTRATION UNDER THE
    EXCHANGE ACT

     The Company's purchase of Shares pursuant to the Offer will reduce the
number of Shares that might otherwise be traded publicly and may reduce the
number of shareholders. Nonetheless, the Company anticipates there will be a
sufficient number of Shares outstanding and publicly traded following
consummation of the Offer to ensure a continued trading market for the Shares.
Based upon published guidelines of the NYSE, the Company believes that following
its purchase of Shares pursuant to the Offer, the Company's remaining Shares
will continue to qualify to be reported on the NYSE. The Shares are currently
"margin securities" under the rules of the Board of Governors of the Federal
Reserve System ("Federal Reserve Board"). This has the effect, among other
things, of allowing brokers to extend credit to their customers using the Shares
as collateral. The Company believes that, following the purchase of Shares
pursuant to the Offer, the Shares will continue to be "margin securities" for
purposes of the Federal Reserve Board's margin regulations.

     The Shares are registered under the Exchange Act, which requires, among
other things, that the Company furnish certain information to its shareholders
and the Commission and comply with the Commission's proxy rules in connection
with meetings of the Company's shareholders. Following the purchase of Shares
pursuant to the Offer, the Shares will continue to be registered under the
Exchange Act.

12. CERTAIN LEGAL MATTERS; REGULATORY APPROVALS

     The Company is not aware of any license or regulatory permit that appears
to be material to the Company's business that might be adversely affected by the
Company's acquisition of Shares as contemplated herein or of any approval or
other action by, or filing with, any government or governmental, administrative
or regulatory authority or agency, domestic or foreign, that would be required
for the acquisition or ownership of Shares by the Company as contemplated
herein. Should any such approval or other action be required, the Company
presently contemplates that such approval or other action will be sought. The
Company is unable to predict whether it will be required to delay the acceptance
for payment of or payment for Shares tendered pursuant to the Offer pending the
outcome of any such matter. There can be no assurance that any such approval or
other action, if needed, would be obtained or would be obtained without
substantial conditions or that the failure to obtain any such approval or other
action might not result in adverse consequences to the Company's business. The
Company's obligations under the Offer to accept for payment and pay for Shares
is subject to certain conditions. See Section 6.

                                       25
<PAGE>   26

13. CERTAIN UNITED STATES FEDERAL INCOME TAX CONSEQUENCES

  General.

     The following is a discussion of the material United States federal income
tax consequences to shareholders with respect to a sale of Shares pursuant to
the Offer. The discussion is based upon the provisions of the Internal Revenue
Code of 1986, as amended (the "Code"), U.S. Department of Treasury regulations,
IRS rulings and judicial decisions, all in effect as of the date hereof and all
of which are subject to change (possibly with retroactive effect) by subsequent
legislative, judicial or administrative action. The discussion does not address
all aspects of United States federal income taxation that may be relevant to a
particular shareholder in light of such shareholder's particular circumstances
or to certain types of holders subject to special treatment under the United
States federal income tax laws (such as certain financial institutions, tax-
exempt organizations, life insurance companies, dealers in securities or
currencies, employee benefit plans or shareholders holding the Shares as part of
a conversion transaction, as part of a hedge or hedging transaction, or as a
position in a straddle for tax purposes). In addition, the discussion below does
not consider the effect of any foreign, state, local or other tax laws that may
be applicable to particular shareholders. The discussion assumes that the Shares
are held as "capital assets" within the meaning of Section 1221 of the Code. The
Company has neither requested nor obtained a written opinion of counsel or a
ruling from the IRS with respect to the tax matters discussed below.

     EACH SHAREHOLDER SHOULD CONSULT HIS OR HER OWN TAX ADVISOR AS TO THE
PARTICULAR UNITED STATES FEDERAL INCOME TAX CONSEQUENCES TO THAT SHAREHOLDER OF
TENDERING SHARES PURSUANT TO THE OFFER AND THE APPLICABILITY AND EFFECT OF ANY
STATE, LOCAL OR FOREIGN TAX LAWS AND RECENT CHANGES IN APPLICABLE TAX LAWS.

  Characterization of the Surrender of Shares Pursuant to the Offer.

     The surrender of Shares by a shareholder to the Company pursuant to the
Offer will be a taxable transaction for United States federal income tax
purposes. The United States federal income tax consequences to a shareholder may
vary depending upon the shareholder's particular facts and circumstances. Under
Section 302 of the Code, the surrender of Shares by a shareholder to the Company
pursuant to the Offer will be treated as a "sale or exchange" of such Shares for
United States federal income tax purposes (rather than as a distribution by the
Company with respect to the Shares held by the tendering shareholder) if the
receipt of cash upon such surrender (i) is "substantially disproportionate" with
respect to the shareholder, (ii) results in a "complete redemption" of the
shareholder's interest in the Company, or (iii) is "not essentially equivalent
to a dividend" with respect to the shareholder (each as described below).

     If any of the above three tests is satisfied, and the surrender of the
Shares is therefore treated as a "sale or exchange" of such Shares for United
States federal income tax purposes, the tendering shareholder will recognize
gain or loss equal to the difference between the amount of cash received by the
shareholder and the shareholder's tax basis in the Shares surrendered pursuant
to the Offer. Any such gain or loss will be capital gain or loss, and will be
long-term capital gain or loss if the Shares have been held for more than one
year.

     If none of the above three tests is satisfied, the tendering shareholder
will be treated as having received a distribution by the Company with respect to
such shareholder's Shares in an amount equal to the cash received by the
shareholder pursuant to the Offer. The distribution will be treated as a
dividend taxable as ordinary income to the extent of the Company's current or
accumulated earnings and profits for tax purposes. The amount of the
distribution in excess of the Company's current or accumulated earnings and
profits will be treated as a return of the shareholder's tax basis in the
Shares, and then as gain from the sale or exchange of such Shares. If a
shareholder is treated as having received a distribution by the Company with
respect to his or her Shares, the shareholder's tax basis in his or her
remaining Shares will generally be adjusted to take into account the
shareholder's return of basis in the Shares surrendered.

                                       26
<PAGE>   27

  Constructive Ownership.

     In determining whether any of the three tests under Section 302 of the Code
is satisfied, shareholders must take into account not only the Shares that are
actually owned by the shareholder, but also Shares that are constructively owned
by the shareholder within the meaning of Section 318 of the Code. Under Section
318 of the Code, a shareholder may constructively own Shares actually owned, and
in some cases constructively owned, by certain related individuals or entities
and Shares that the shareholder has the right to acquire by exercise of an
option or by conversion.

  Proration.

     Contemporaneous dispositions or acquisitions of Shares by a shareholder or
related individuals or entities may be deemed to be part of a single integrated
transaction and may be taken into account in determining whether any of the
three tests under Section 302 of the Code has been satisfied. Each shareholder
should be aware that because proration may occur in the Offer, even if all the
Shares actually and constructively owned by a shareholder are tendered pursuant
to the Offer, fewer than all of such Shares may be purchased by the Company.
Thus, proration may affect whether the surrender by a shareholder pursuant to
the Offer will meet any of the three tests under Section 302 of the Code.

  Section 302 Tests.

     The receipt of cash by a shareholder will be "substantially
disproportionate" if the percentage of the outstanding Shares in the Company
actually and constructively owned by the shareholder immediately following the
surrender of Shares pursuant to the Offer is less than 80% of the percentage of
the outstanding Shares actually and constructively owned by such shareholder
immediately before the sale of Shares pursuant to the Offer. Shareholders should
consult their tax advisors with respect to the application of the "substantially
disproportionate" test to their particular situations.

     The receipt of cash by a shareholder will be a "complete redemption" if
either (i) the shareholder owns no Shares in the Company either actually or
constructively immediately after the Shares are surrendered pursuant to the
Offer, or (ii) the shareholder actually owns no Shares in the Company
immediately after the surrender of Shares pursuant to the Offer and, with
respect to Shares constructively owned by the shareholder immediately after the
Offer, the shareholder is eligible to waive (and effectively waives)
constructive ownership of all such Shares under procedures described in Section
302(c) of the Code. A director, officer or employee of the Company is not
eligible to waive constructive ownership under the procedures described in
Section 302(c) of the Code.

     Even if the receipt of cash by a shareholder fails to satisfy the
"substantially disproportionate" test or the "complete redemption" test, a
shareholder may nevertheless satisfy the "not essentially equivalent to a
dividend" test if the shareholder's surrender of Shares pursuant to the Offer
results in a "meaningful reduction" in the shareholder's interest in the
Company. Whether the receipt of cash by a shareholder will be "not essentially
equivalent to a dividend" will depend upon the individual shareholder's facts
and circumstances. The IRS has indicated in published rulings that even a small
reduction in the proportionate interest of a small minority shareholder in a
publicly held corporation who exercises no control over corporate affairs may
constitute such "meaningful reduction." Shareholders expecting to rely upon the
"not essentially equivalent to a dividend" test should consult their own tax
advisors as to its application in their particular situation.

  Corporate Shareholder Dividend Treatment.

     If a sale of Shares by a corporate shareholder is treated as a dividend,
the corporate shareholder may be entitled to claim a deduction equal to 70% of
the dividend under Section 243 of the Code, subject to applicable limitations.
Corporate shareholders should, however, consider the effect of Section 246(c) of
the Code, which disallows the 70% dividends received deduction with respect to
stock that is held for 45 days or less. For this purpose, the length of time a
taxpayer is deemed to have held stock may be reduced by periods during which the
taxpayer's risk of loss with respect to the stock is diminished by reason of the
existence of certain options or other transactions. Moreover, under Section 246A
of the Code, if a corporate shareholder has incurred
                                       27
<PAGE>   28

indebtedness directly attributable to an investment in Shares, the 70%
dividends-received deduction may be reduced.

     In addition, amounts received by a corporate shareholder pursuant to the
Offer that are treated as a dividend may constitute an "extraordinary dividend"
under Section 1059 of the Code. The "extraordinary dividend" rules of the Code
are highly complicated. Accordingly, any corporate shareholder that might have a
dividend as a result of the sale of shares pursuant to the Offer should review
the "extraordinary dividend" rules to determine the applicability and impact of
such rules to it.

  Additional Tax Consideration.

     The distinction between long-term capital gains and ordinary income is
relevant because, in general, individuals currently are subject to taxation at a
reduced rate on their "net capital gain" (i.e., the excess of net long-term
capital gains over net short-term capital losses) for the year. Currently, the
maximum such federal rate on net capital gain is 20%, while the maximum rate on
ordinary income (including short-term capital gain) is 39.6%. Shareholders are
urged to consult their own tax advisors regarding any possible impact on their
obligation to make estimated tax payments as a result of the recognition of any
capital gain (or the receipt of any ordinary income) caused by the surrender of
any Shares to the Company pursuant to the Offer.

  Foreign Shareholders.

     The Company will withhold United States federal income tax at a rate of 30%
from gross proceeds paid pursuant to the Offer to a foreign shareholder or his
agent, unless the Company determines that a reduced rate of withholding is
applicable pursuant to a tax treaty, that an exemption from withholding is
applicable because such gross proceeds are effectively connected with the
conduct of a trade or business by the foreign shareholder within the United
States or that the shareholder meets the "complete redemption," "substantially
disproportionate" or "not essentially equivalent to a dividend" tests described
above. For this purpose, a foreign shareholder is any shareholder that is not
(i) a citizen or resident of the United States, (ii) a domestic corporation or
domestic partnership, (iii) an estate the income of which is subject to United
States federal income tax regardless of its source, or (iv) a trust if a court
within the United States is able to exercise primary supervision over the
administration of the trust, and one or more United States persons have the
authority to control all substantial decisions of the trust. Without definite
knowledge to the contrary, the Company will determine whether a shareholder is a
foreign shareholder by reference to the shareholder's address. A foreign
shareholder may be eligible to file for a refund of such tax or a portion of
such tax if such shareholder (i) meets the "complete redemption," "substantially
disproportionate" or "not essentially equivalent to a dividend" tests described
above, (ii) is entitled to a reduced rate of withholding pursuant to a treaty
and the Company withheld at a higher rate, or (iii) is otherwise able to
establish that no tax or a reduced amount of tax was due. To claim an exemption
from withholding on the ground that gross proceeds paid pursuant to the Offer
are effectively connected with the conduct of a trade or business by a foreign
shareholder within the United States or that the foreign shareholder is entitled
to the benefits of a tax treaty, the foreign shareholder must deliver to the
Depositary (or other person who is otherwise required to withhold United States
tax) a properly executed statement claiming such exemption or benefits. Such
statements may be obtained from the Depositary. Foreign shareholders are urged
to consult their own tax advisors regarding the application of United States
federal income tax withholding, including eligibility for a withholding tax
reduction or exemption and the refund procedures.

  Backup Withholding.

     See Section 3 with respect to the application of the United States federal
income tax backup withholding.

     THE TAX DISCUSSION SET FORTH ABOVE IS INCLUDED FOR GENERAL INFORMATION ONLY
AND MAY NOT APPLY TO SHARES ACQUIRED IN CONNECTION WITH THE EXERCISE OF STOCK
OPTIONS OR PURSUANT TO OTHER COMPENSATION ARRANGEMENTS WITH THE COMPANY. THE TAX
CONSEQUENCES OF A SALE PURSUANT TO THE OFFER MAY VARY DEPENDING UPON, AMONG
OTHER THINGS, THE PARTICULAR CIR-

                                       28
<PAGE>   29

CUMSTANCES OF THE TENDERING SHAREHOLDER. NO INFORMATION IS PROVIDED
HEREIN AS TO THE STATE, LOCAL OR FOREIGN TAX CONSEQUENCES OF THE TRANSACTION
CONTEMPLATED BY THE OFFER. SHAREHOLDERS ARE URGED TO CONSULT THEIR OWN TAX
ADVISORS TO DETERMINE THE PARTICULAR FEDERAL, STATE, LOCAL AND FOREIGN TAX
CONSEQUENCES TO THEM OF TENDERING SHARES PURSUANT TO THE OFFER AND THE EFFECT OF
THE STOCK OWNERSHIP ATTRIBUTION RULES DESCRIBED ABOVE.

14. EXTENSION OF THE OFFER; TERMINATION; AMENDMENT

     The Company expressly reserves the right, in its sole discretion, at any
time and from time to time, and regardless of whether or not any of the events
set forth in Section 6 shall have occurred or shall be deemed by the Company to
have occurred, to extend the period of time during which the Offer is open and
thereby delay acceptance for payment of, and payment for, any Shares by giving
oral or written notice of such extension to the Depositary and making a public
announcement thereof. There can be no assurance, however, that the Company will
exercise its right to extend the Offer. During any such extension, all Shares
previously tendered and not properly withdrawn will remain subject to the Offer
and to the rights of a tendering shareholder to withdraw such shareholder's
Shares. See Section 4. The Company also expressly reserves the right, in its
reasonable discretion, to terminate the Offer and not accept for payment or pay
for any Shares not theretofore accepted for payment or paid for or, subject to
applicable law, to postpone payment for Shares upon the occurrence of any of the
conditions specified in Section 6 hereof by giving oral or written notice of
such termination or postponement to the Depositary and making a public
announcement thereof. The Company's reservation of the right to delay payment
for Shares which it has accepted for payment is limited by Rule 13e-4(f)(5)
promulgated under the Exchange Act, which requires that the Company must pay the
consideration offered or return the Shares tendered promptly after termination
or withdrawal of a tender offer. Subject to compliance with applicable law, the
Company further reserves the right, in its reasonable discretion, and regardless
of whether any of the events set forth in Section 6 shall have occurred or shall
be deemed by the Company to have occurred, to amend the Offer in any respect
(including, without limitation, by decreasing or increasing the consideration
offered in the Offer to holders of Shares or by decreasing or increasing the
number of Shares being sought in the Offer). Amendments to the Offer may be made
at any time and from time to time effected by public announcement thereof, such
announcement, in the case of an extension, to be issued no later than 9:00 a.m.,
Eastern Time, on the next business day after the last previously scheduled or
announced Expiration Date. Any public announcement made pursuant to the Offer
will be disseminated promptly to shareholders in a manner reasonably designed to
inform shareholders of such change. Without limiting the manner in which the
Company may choose to make a public announcement, except as otherwise required
by applicable law, the Company shall have no obligation to publish, advertise or
otherwise communicate any such public announcement other than by making a
release to the Dow Jones News Service. Material changes to information
previously provided to holders of Shares in the Offer or in documents furnished
subsequent thereto will be disseminated to holders of Shares in compliance with
Rule 13e-4(e)(2) promulgated by the Commission under the Exchange Act.

     If the Company materially changes the terms of the Offer or the information
concerning the Offer, or if it waives a material condition of the Offer, the
Company will extend the Offer to the extent required by Rules 13e-4(d)(2) and
13e-4(e)(2) promulgated under the Exchange Act. These rules provide that the
minimum period during which an offer must remain open following material changes
in the terms of the Offer or information concerning the Offer (other than a
change in price or a change in percentage of securities sought) will depend on
the facts and circumstances, including the relative materiality of such terms or
information. If (i)(a) the Company increases or decreases the price to be paid
for Shares, (b) increases the number of Shares being sought in the Offer and, in
the event of an increase in the number of Shares being sought, such increase
exceeds 2% of the outstanding Shares, or (c) decreases the number of Shares
being sought, and (ii) the Offer is scheduled to expire at any time earlier than
the expiration of a period ending on the tenth (10th) business day from, and
including, the date that such notice of an increase or decrease is first
published, sent or given in the manner specified in this Section 14, the Offer
will be extended until the expiration of such period of ten (10) business days.
For the purposes of the Offer, a "business day" means any
                                       29
<PAGE>   30

day other than a Saturday, Sunday or Federal holiday and consists of the time
period from 12:01 a.m. through 12:00 Midnight, Eastern Time.

15. FEES AND EXPENSES

     The Company has retained Corporate Investor Communications, Inc. as the
Information Agent in connection with the Offer. The Information Agent may
contact shareholders by mail, telephone, telex, telegraph or other electronic
means and personal interview, and may request brokers, dealers and other nominee
shareholders to forward materials relating to the Offer to beneficial owners.
The Information Agent will receive reasonable and customary compensation for its
services. The Company will also reimburse the Information Agent for
out-of-pocket expenses, including reasonable attorneys' fees, and has agreed to
indemnify the Information Agent against certain liabilities in connection with
the Offer, including certain liabilities under the federal securities laws.

     The Company has retained Harris Trust and Savings Bank to act as the
Depositary in connection with the Offer. The Depositary will receive reasonable
and customary compensation for its services, will be reimbursed by the Company
for certain reasonable out-of-pocket expenses and will be indemnified against
certain liabilities in connection with the Offer, including certain liabilities
under the federal securities laws.

     Wells Fargo Bank, N.A. acts as the trustee of the Company's ESOP. U.S.
Stock Transfer Corporation acts as its agent to receive instructions from ESOP
participants regarding the Offer, and the agent or ESOP Trustee may contact
participants in such plan by mail, telephone, telex, telegraph and personal
interviews. The ESOP Trustee and its agent will each receive reasonable and
customary compensation for their services and each will be reimbursed for
certain out-of-pocket expenses.

     Fidelity Management Trust Company acts as the trustee of the Company's
401(k) Plan. Management Information Services acts as its agent to receive
instructions from 401(k) Plan participants regarding the Offer, and the agent or
401(k) Plan Trustee may contact participants in such plan by mail, telephone,
telex, telegraph and personal interviews. The 401(k) Plan Trustee and its agent
will each receive reasonable and customary compensation for their services and
each will be reimbursed for certain out-of-pocket expenses.

     No fees or commissions will be payable by the Company to brokers, dealers
or other persons for soliciting tenders of Shares pursuant to the Offer.
Shareholders holding Shares through brokers or banks are urged to consult the
brokers or banks to determine whether transaction costs are applicable if
shareholders tender Shares through such brokers or banks and not directly to the
Depositary. The Company, however, upon request through the Information Agent,
will reimburse brokers, dealers and commercial banks for customary mailing and
handling expenses incurred by them in forwarding the Offer and related materials
to the beneficial owners of Shares held by them as a nominee or in a fiduciary
capacity. No broker, dealer, commercial bank or trust company has been
authorized to act as the agent of the Company for purposes of the Offer. The
Company will pay or cause to be paid all stock transfer taxes, if any, on its
purchase of Shares except as otherwise provided in Instruction 6 in the Letter
of Transmittal.

16. ADDITIONAL INFORMATION

     The Company is subject to the informational requirements of the Exchange
Act and, in accordance therewith, files reports, proxy statements and other
information with the Commission. Such reports, proxy statements and other
information may be inspected and copied at the public reference facilities
maintained by the Commission at Room 1024, 450 Fifth Street, N.W., Washington,
D.C. 20549 and at the Commission's regional offices at 7 World Trade Center,
13th Floor, Suite 1300, New York, New York 10048 and Suite 1400, Citicorp
Center, 500 West Madison Street, Chicago, Illinois 60661. Copies of such
material may also be obtained by mail from the Public Reference Section of the
Commission at 450 Fifth Street, N.W., Washington, D.C. 20549 at prescribed
rates. Such information may also be accessed electronically by means of the
Commission's home page on the Internet (http://www.sec.gov). Shareholders also
may request a copy of these filings, at no cost, by writing or telephoning the
Company at the following address: Giant Industries, Inc., Attn: Corporate
Secretary, 23733 N. Scottsdale Road, Scottsdale, Arizona 85255, (480) 585-8888.

                                       30
<PAGE>   31

17. MISCELLANEOUS

     This Offer is being made to all holders of Shares. The Company is not aware
of any jurisdiction where the making of the Offer is not in compliance with
applicable law. If the Company becomes aware of any jurisdiction where the
making of the Offer or the acceptance of Shares pursuant thereto is not in
compliance with any valid applicable law, the Company will make a good faith
effort to comply with the applicable law. If, after such good faith effort, the
Company cannot comply with the applicable law, the Offer will not be made to
(nor will tenders be accepted from or on behalf of) the holders of Shares in
such jurisdiction. In any jurisdiction the securities, blue sky or other laws of
which require the Offer to be made by a licensed broker or dealer, the Offer
shall be deemed to be made on the Company's behalf by one or more registered
brokers or dealers licensed under the laws of the jurisdiction. Pursuant to Rule
13e-4 of the General Rules and Regulations of the Commission under the Exchange
Act, the Company has filed with the Commission an Issuer Tender Offer Statement
on Schedule 13E-4 that contains additional information with respect to the
Offer. Such Schedule 13E-4, including the exhibits and any amendments thereto,
may be examined, and copies may be obtained, at the same places and in the same
manner as is set forth in Section 16 with respect to information concerning the
Company.

     THE COMPANY HAS NOT AUTHORIZED ANY PERSON TO MAKE ANY RECOMMENDATION ON
BEHALF OF THE COMPANY AS TO WHETHER SHAREHOLDERS SHOULD TENDER OR REFRAIN FROM
TENDERING SHARES PURSUANT TO THE OFFER. THE COMPANY HAS NOT AUTHORIZED ANY
PERSON TO GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATION IN CONNECTION WITH
THE OFFER OTHER THAN THOSE CONTAINED IN THIS OFFER TO PURCHASE OR IN THE RELATED
LETTER OF TRANSMITTAL. IF GIVEN OR MADE, ANY SUCH RECOMMENDATION OR ANY SUCH
INFORMATION OR REPRESENTATION MUST NOT BE RELIED UPON AS HAVING BEEN AUTHORIZED
BY THE COMPANY.

                                          GIANT INDUSTRIES, INC.

December 21, 1999

                                       31

<PAGE>   1

                                                                  EXHIBIT (A)(2)

                             LETTER OF TRANSMITTAL

                        TO TENDER SHARES OF COMMON STOCK

                                       OF

                             GIANT INDUSTRIES, INC.

                       PURSUANT TO THE OFFER TO PURCHASE
                            DATED DECEMBER 21, 1999

         THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE
                AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000,
                         UNLESS THE OFFER IS EXTENDED.

                        The Depositary for the Offer is:

                         HARRIS TRUST AND SAVINGS BANK

<TABLE>
<S>                                <C>                                <C>
             By Mail:                  By Facsimile Transmission:       By Hand or Overnight Courier:
  Harris Trust and Savings Bank     (for Eligible Institutions Only)    Harris Trust and Savings Bank
   c/o Harris Trust Company of               (212) 701-7636              c/o Harris Trust Company of
             New York                        (212) 701-7637                        New York
       Wall Street Station               Confirm by Telephone:                  Receive Window
          P.O. Box 1010                                                   88 Pine Street, 19th Floor
  New York, New York 10268-1010              (212) 701-7624                New York, New York 10005
</TABLE>

 THIS LETTER OF TRANSMITTAL, INCLUDING THE ACCOMPANYING INSTRUCTIONS, SHOULD BE
         READ CAREFULLY BEFORE THIS LETTER OF TRANSMITTAL IS COMPLETED.

     DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OR VIA A FACSIMILE
TRANSMISSION OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.
DELIVERY TO GIANT INDUSTRIES, INC. OR THE BOOK-ENTRY TRANSFER FACILITY WILL NOT
CONSTITUTE A VALID DELIVERY TO THE DEPOSITARY. DELIVERIES TO GIANT INDUSTRIES,
INC. WILL NOT BE FORWARDED TO THE DEPOSITARY AND THEREFORE WILL NOT CONSTITUTE
VALID DELIVERY.

     YOU MUST SIGN THIS LETTER OF TRANSMITTAL IN THE APPROPRIATE SPACE PROVIDED
THEREFOR, WITH SIGNATURE GUARANTEE IF REQUIRED, AND COMPLETE THE SUBSTITUTE FORM
W-9 SET FORTH BELOW. SEE INSTRUCTION 1.
<PAGE>   2

<TABLE>
<CAPTION>
- ------------------------------------------------------------------------------------------------------------------------
                                             DESCRIPTION OF SHARES TENDERED
- ------------------------------------------------------------------------------------------------------------------------
      NAME(S) AND ADDRESS(ES) OF REGISTERED HOLDER(S)
       (PLEASE FILL IN, IF BLANK, EXACTLY AS NAME(S)                  SHARE CERTIFICATE(S) AND SHARES TENDERED
              APPEAR(S) ON SHARE CERTIFICATES)                         (ATTACH ADDITIONAL LIST, IF NECESSARY)
- ------------------------------------------------------------------------------------------------------------------------
                                                                                   TOTAL NUMBER OF
                                                                                  SHARES EVIDENCED        NUMBER OF
                                                              SHARE CERTIFICATE       BY SHARE             SHARES
                                                                 NUMBER(S)*        CERTIFICATE(S)        TENDERED**
<S>                                                          <C>                 <C>                 <C>
                                                             ------------------------------------------------------
                                                             ------------------------------------------------------
                                                             ------------------------------------------------------
                                                             ------------------------------------------------------
                                                             ------------------------------------------------------
                                                                Total Shares:
- ------------------------------------------------------------------------------------------------------------------------
  * Need not be completed by stockholders delivering Shares by Book-Entry Transfer.
 ** Unless otherwise indicated, it will be assumed that all Shares evidenced by each Share Certificate delivered to the
    Depository are being tendered hereby. See Instruction 4.
- ------------------------------------------------------------------------------------------------------------------------
</TABLE>

     This Letter of Transmittal is to be completed only (a) if certificates
representing Shares (as defined below) are to be forwarded herewith or (b) if
tenders of Shares are to be made concurrently by book-entry transfer to the
account maintained by the Depositary at The Depository Trust Company (the
"Book-Entry Transfer Facility") pursuant to the procedures set forth in Section
3 of the Giant Industries, Inc. Offer to Purchase (the "Offer to Purchase").
Delivery of documents to the Book-Entry Transfer Facility does not constitute
delivery to the Depositary.

     Participants in the Company's employee stock ownership plan may not use
this Letter of Transmittal to direct the tender of Shares held through such plan
("ESOP Shares"), nor may participants in the Company's 401(k) plan use this
Letter of Transmittal to direct the tender of Shares held through the 401(k)
plan ("401(k) Shares"). Such participants must follow the instructions set forth
in the materials on YELLOW paper for the ESOP participants and PINK paper for
the 401(k) Plan participants. Wells Fargo Bank, N.A., the trustee for the
Company's employee stock ownership plan, will submit one Letter of Transmittal
for such plan on behalf of all tendering employee stock ownership plan
participants. Fidelity Management Trust Company, the trustee for the Company's
401(k) plan, will submit one Letter of Transmittal for such plan on behalf of
all tendering 401(k) plan participants.

     If a holder owns Shares apart from ESOP Shares or 401(k) Shares that he or
she desires to tender, such holder must submit both this Letter of Transmittal
to tender the non-ESOP Shares and non-401(k) Shares, and must follow the
instructions set forth in the materials on the YELLOW paper for ESOP
participants and the PINK paper for 401(k) participants to tender the ESOP
Shares or 401(k) Shares.

     Shareholders whose Share certificates are not immediately available or who
cannot deliver such certificates and all other documents required by this Letter
of Transmittal to the Depositary on or prior to the Expiration Date (as defined
in the Offer to Purchase), or who cannot comply with the procedure for
book-entry transfer on a timely basis, may nevertheless tender their Shares
pursuant to the guaranteed delivery procedure set forth in Section 3 of the
Offer to Purchase. See Instruction 2.

[ ] CHECK HERE IF TENDERED SHARES ARE BEING DELIVERED BY BOOK-ENTRY TRANSFER TO
    THE DEPOSITARY'S ACCOUNT AT THE BOOK-ENTRY TRANSFER FACILITY AND COMPLETE
    THE FOLLOWING:

Name of Tendering Individual:
- --------------------------------------------------------------------------------

Account Number: ---------- Transaction Code Number: ----------

[ ] CHECK HERE IF TENDERED SHARES ARE BEING DELIVERED PURSUANT TO A NOTICE OF
    GUARANTEED DELIVERY PREVIOUSLY SENT TO THE DEPOSITARY AND COMPLETE THE
    FOLLOWING:

Name(s) of Registered Holder(s):
- --------------------------------------------------------------------------------

Date of Execution of Notice of Guaranteed Delivery:
- --------------------------------------------------------------------------------

Name of Institution which Guaranteed Delivery:
- --------------------------------------------------------------------------------

Give Account Number and Transaction Code if Delivered by Book-Entry Transfer:
- --------------------------------------------------------------------------------

DTC Account No.:
- --------------------------------------------------------------------------------

DTC Transaction Code No.:
- --------------------------------------------------------------------------------
<PAGE>   3

              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY.

TO HARRIS TRUST AND SAVINGS BANK, AS DEPOSITARY:

     The undersigned hereby tenders to Giant Industries, Inc., a Delaware
corporation (the "Company"), the above-described shares of common stock, $.01
par value, of the Company (the "Shares"), at a price of $9.00 per Share, net to
the seller in cash, without interest thereon, pursuant to the Company's offer to
purchase up to 1,333,333 Shares, upon the terms and subject to the conditions
set forth in the Company's Offer to Purchase dated December 21, 1999 (the "Offer
to Purchase"), receipt of which is hereby acknowledged, and in this Letter of
Transmittal (which, as amended or supplemented from time to time, together
constitute the "Offer").

     Subject to, and effective upon, acceptance for payment of the Shares
tendered hereby in accordance with the terms and subject to the conditions of
the Offer (including, if the Offer is extended or amended, the terms and
conditions of such extension or amendment), the undersigned hereby sells,
assigns and transfers to, or upon the order of, the Company, all right, title
and interest in and to all the Shares tendered hereby or orders the registration
of all such Shares if tendered by book-entry transfer and hereby irrevocably
constitutes and appoints the Depositary as the true and lawful agent and
attorney-in-fact of the undersigned with respect to such Shares, with full power
of substitution (such power of attorney being deemed to be an irrevocable power
coupled with an interest), to: (a) deliver certificate(s) representing such
Shares or transfer ownership of such Shares on the account books maintained by
the Book-Entry Transfer Facility, together, in either such case, with all
accompanying evidences of transfer and authenticity, to or upon the order of the
Company upon receipt by the Depositary, as the undersigned's agent, of the
Purchase Price (as defined below) with respect to such Shares; (b) present
certificates for such Shares for cancellation and transfer on the Company's
books; and (c) receive all benefits and otherwise exercise all rights of
beneficial ownership of such Shares, subject to the next paragraph, all in
accordance with the terms and subject to the conditions of the Offer.

     The undersigned hereby covenants, represents and warrants to the Company
that:

     - the undersigned has full power and authority to tender, sell, assign and
       transfer the Shares tendered hereby and that, when and to the extent the
       same are accepted for payment by the Company, the Company will acquire
       good, marketable and unencumbered title thereto, free and clear of all
       security interests, liens, restrictions, charges, encumbrances,
       conditional sales agreements or other obligations relating to the sale or
       transfer of such Shares, and not subject to any adverse claims;

     - the undersigned understands that tenders of Shares pursuant to any one of
       the procedures described in Section 3 of the Offer to Purchase and in the
       instructions hereto will constitute the undersigned's acceptance of the
       terms and conditions of the Offer, including the undersigned's
       representation and warranty that (a) the undersigned has a net long
       position in the Shares or equivalent securities at least equal to the
       Shares tendered within the meaning of Rule 14e-4 under the Securities
       Exchange Act of 1934, as amended ("Rule 14e-4"), and (b) such tender of
       Shares complies with Rule 14e-4;

     - the undersigned will, upon request, execute and deliver any additional
       documents deemed by the Depositary or the Company to be necessary or
       desirable to complete the sale, assignment and transfer of the Shares
       tendered hereby; and

     - the undersigned has read, understands and agrees to all of the terms and
       conditions of the Offer.

     The undersigned understands that tenders of Shares pursuant to any one of
the procedures described in Section 3 of the Offer to Purchase and in the
instructions hereto will constitute a binding agreement between the undersigned
and the Company, upon the terms and subject to the conditions of the Offer. The
undersigned acknowledges that no interest will be paid on the Purchase Price for
tendered Shares regardless of any extension of the Offer or any delay in making
such payment.

     All authority herein conferred or agreed to be conferred shall survive the
death or incapacity of the undersigned, and any obligation of the undersigned
hereunder shall be binding upon the heirs, personal representatives, executors,
administrators, trustees, successors, assigns, trustees in bankruptcy and legal
representatives of the undersigned. Except as stated in the Offer, this tender
is irrevocable.

     The name(s) and address(es) of the registered holder(s) should be printed,
if they are not already printed above, exactly as they appear on the
certificates representing Shares tendered hereby. The certificate numbers, the
number of Shares represented by such certificates and the number of Shares that
the undersigned wishes to tender should be set forth in the appropriate boxes
above.
<PAGE>   4

     The undersigned understands that:

     - the Company has, upon the terms and subject to the conditions of the
       Offer, determined a single per Share price of $9.00 per Share, net to the
       seller in cash, without interest thereon (the "Purchase Price");

     - the Company will pay for Shares validly tendered and not withdrawn prior
       to the Expiration Date pursuant to the Offer, taking into account the
       number of Shares so tendered by tendering shareholders;

     - all Shares validly tendered prior to the Expiration Date and not
       withdrawn will be purchased at the Purchase Price, upon the terms and
       subject to the conditions of the Offer, including its proration
       provisions;

     - the Company will return all other Shares not purchased pursuant to the
       Offer, including Shares not purchased because of proration;

     - the Company has reserved the right, in its sole discretion, to purchase
       more than 1,333,333 Shares pursuant to the Offer; and

     - the tender of Shares pursuant to any of the procedures described in
       Section 3 of the Offer to Purchase and in the instructions hereto will
       constitute an agreement between the undersigned and the Company upon the
       terms and subject to the conditions of the Offer.

     The undersigned recognizes that, under certain circumstances set forth in
the Offer to Purchase, the Company may terminate or amend the Offer or may
postpone the acceptance for payment of, or the payment for, Shares tendered or
may accept for payment fewer than all of the Shares tendered hereby. In any such
event, the undersigned understands that certificate(s) for any Shares not
tendered or not purchased will be returned to the undersigned at the address
indicated below, unless otherwise indicated under the box entitled "Special
Payment Instructions" or the box entitled "Special Delivery Instructions" below.

     The check for the aggregate net Purchase Price for such of the tendered
Shares as are purchased will be issued to the order of the undersigned and
mailed to the address indicated below, unless otherwise indicated under the box
entitled "Special Payment Instructions" or the box entitled "Special Delivery
Instructions" below.

     In the event that both the "Special Payment Instructions" and the "Special
Delivery Instructions" are completed, please issue the check for the Purchase
Price and/or return any Shares not so tendered or accepted for payment in the
name of and deliver said check and/or return such Shares to the person or
persons so indicated. Shareholders tendering Shares by book-entry transfer may
request that any Shares not accepted for payment be returned by crediting such
account maintained at the Book-Entry Transfer Facility by making an appropriate
entry under "Special Payment Instructions."

     The undersigned acknowledges that the Company has no obligation, pursuant
to the "Special Payment Instructions," to transfer any Shares from the name of
its registered holder(s) thereof, or to order the registration or transfer of
any Shares tendered by book-entry transfer, if the Company does not purchase any
of such Shares.

                    NOTE: SIGNATURES MUST BE PROVIDED BELOW.
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY.
<PAGE>   5

          ------------------------------------------------------------

                          SPECIAL PAYMENT INSTRUCTIONS
                      (SEE INSTRUCTIONS 1, 4, 5, 6 AND 8)

        To be completed ONLY if Share Certificates for Shares not tendered or
   not purchased and/or the check for the Purchase Price of Shares are to be
   issued in the name of someone other than the undersigned, or if Shares
   tendered hereby and delivered by Book-Entry Transfer which are not
   purchased are to be returned by credit to an account maintained at a
   Book-Entry Transfer Facility other than that designated above.

   Issue check and/or certificate to:

   Name
   -------------------------------------------------------------------
                                    (PLEASE PRINT)

   Address
   -------------------------------------------------------------------

          ------------------------------------------------------------
                               (INCLUDE ZIP CODE)

          ------------------------------------------------------------
                 (TAX IDENTIFICATION OR SOCIAL SECURITY NUMBER)

   [ ] Credit unpurchased Shares delivered by Book-Entry Transfer to the
       Book-Entry Transfer Facility account set forth below.

   Book Entry Transfer facility:

          ------------------------------------------------------------
                                     (NAME)

          ------------------------------------------------------------
                                (ACCOUNT NUMBER)
          ------------------------------------------------------------
          ------------------------------------------------------------

                         SPECIAL DELIVERY INSTRUCTIONS
                      (SEE INSTRUCTIONS 1, 4, 5, 6 AND 7)

        To be completed ONLY if Share Certificates for Shares not tendered or
   not purchased and/or the check for the Purchase Price of Shares purchased
   are to be sent to someone other than the undersigned, or to the
   undersigned at an address other than that shown above.

   Mail check and/or certificate to:

   Name
   -------------------------------------------------------------------
                                    (PLEASE PRINT)

   Address
   -------------------------------------------------------------------

          ------------------------------------------------------------
                               (INCLUDE ZIP CODE)

          ------------------------------------------------------------
<PAGE>   6

                                    ODD LOTS
                              (SEE INSTRUCTION 7)

     To be completed ONLY if Shares are being tendered by or on behalf of a
person owning, beneficially or of record, as of the close of business on
December 20, 1999, and who continues to own, beneficially or of record, as of
the Expiration Date, an aggregate of fewer than 100 Shares (not including any
Shares held pursuant to the Company's employee stock ownership plan or 401(k)
plan).

     The undersigned either (check one box):

     [ ]  was the beneficial or record owner of, as of the close of business on
          December 20, 1999, and continues to own, beneficially or of record as
          of the Expiration Date, an aggregate of fewer than 100 Shares (not
          including any Shares held pursuant to the Company's employee stock
          ownership plan or 401(k) Plan), all of which are being tendered; or

     [ ]  is a broker, dealer, commercial bank, trust company, or other nominee
          that (a) is tendering, for the beneficial owner(s) thereof, Shares
          with respect to which it is the record holder, and (b) believes, based
          upon representations made to it by such beneficial owner(s), that each
          such person was the beneficial or record owner of, as of the close of
          business on December 20, 1999, and continues to own beneficially or of
          record as of the Expiration Date, an aggregate of fewer than 100
          Shares (not including any Shares held pursuant to the Company's
          employee stock ownership plan or 401(k) Plan) and is tendering all of
          such Shares.
<PAGE>   7

         THE FOLLOWING MUST BE COMPLETED BY ALL TENDERING SHAREHOLDERS.
                              (SEE INSTRUCTION 11)

                      PAYER'S NAME: GIANT INDUSTRIES, INC.

                                   IMPORTANT:
                             STOCKHOLDERS SIGN HERE
                (PLEASE COMPLETE SUBSTITUTE FORM W-9 ON REVERSE)

X
- --------------------------------------------------------------------------------

X
- --------------------------------------------------------------------------------
                           SIGNATURE(S) OF HOLDER(S)

Dated:
- ---------------------------

(Must be signed by registered holder(s) exactly as name(s) appear(s) on Share
certificate(s) or on a security position listing or by person(s) authorized to
become registered holder(s) by Share Certificates and documents transmitted
herewith. If signature is by a trustee, executor, administrator, guardian,
attorney-in-fact, agent, officer of a corporation or other person acting in a
fiduciary or representative capacity, please provide the following information.
See Instructions 1 and 5.)

Name(s)
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                                 (PLEASE PRINT)

Capacity (Full Title)
- --------------------------------------------------------------------------------
                              (SEE INSTRUCTION 5)

Address
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                               (INCLUDE ZIP CODE)

Area Code and Telephone Number
                           -----------------------------------------------------

Taxpayer Identification or Social Security No.
- --------------------------------------------------------------------------------
                 (COMPLETE SUBSTITUTE FORM W-9 ON REVERSE SIDE)

                           GUARANTEE OF SIGNATURE(S)
                   (IF REQUIRED -- SEE INSTRUCTIONS 1 AND 5)

Authorized Signature
- --------------------------------------------------------------------------------

Name
- --------------------------------------------------------------------------------
                                 (PLEASE PRINT)

Name of Firm
- --------------------------------------------------------------------------------

Address
- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------
                               (INCLUDE ZIP CODE)

Area Code and Telephone Number
- --------------------------------------------------------------------------------

Dated:
- ---------------------------
<PAGE>   8

<TABLE>
<S>                          <C>                                                           <C>
- --------------------------------------------------------------------------------------------------------------------------

  SUBSTITUTE                   PART I -- PLEASE PROVIDE YOUR TIN IN THE BOX AT RIGHT AND
  FORMW-9                      CERTIFY BY SIGNING AND DATING BELOW.                         -----------------------------
                                                                                               Social Security Number
                                                                                            or
                                                                                             --------------------------
                                                                                               Employer Identification
                                                                                                       Number
                                                                                               (if awaiting TIN write
                                                                                                   "Applied For")
                             ---------------------------------------------------------------------------------------------

 Department of the             PART II -- For Payees exempt from backup withholding, see the enclosed Guidelines for
  Treasury                     Certification of Taxpayer Identification Number on Substitute Form W-9 and completed as
  Internal Revenue             instructed therein.
  Service                      -------------------------------------------------------------------------------------------
  PAYOR'S REQUEST FOR          Certification -- Under the penalties of perjury, I certify that:
  TAXPAYER IDENTIFICATION
      NUMBER ("TIN")           (1) The number shown on this form is my correct Taxpayer Identification Number (or  a
                               Taxpayer Identification Number has not been issued to me) and either (a) I have  mailed or
                                   delivered an application to receive a Taxpayer Identification Number to the
                                   appropriate Internal Revenue Service ("IRS") or Social Security Administration
                                   office,  or (b) I intend to mail or deliver an application in the near future. (I
                                   understand that if  I do not provide a Taxpayer Identification Number within 60 days,
                                   31% of all  reportable payments made to me thereafter will be withheld until I provide
                                   a number); and
                               (2) I am not subject to backup withholding either because I have not been notified by the
                               IRS that I am subject to backup withholding as a result of a failure to report all
                                   interest  or dividends, or the IRS has notified me that I am no longer subject to
                                   backup withholding.
                               -------------------------------------------------------------------------------------------

                               SIGNATURE ________________________________________  DATE ________________
- --------------------------------------------------------------------------------------------------------------------------
</TABLE>

CERTIFICATION INSTRUCTIONS -- You must cross out item (2) above if you have been
notified by the IRS that you are subject to backup withholding because of
underreporting interest or dividends on your tax return. If, however, after
being notified by the IRS that you were subject to backup withholding you
received another notification from the IRS that you are no longer subject to
backup withholding, do not cross out item (2). (Also see instructions in the
enclosed Taxpayer Identification Guidelines).

NOTE: FAILURE TO COMPLETE AND RETURN THIS FORM MAY RESULT IN BACKUP WITHHOLDING
      OF 31 % OF ANY PAYMENTS MADE TO YOU PURSUANT TO THIS OFFER. PLEASE REVIEW
      THE ENCLOSED GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
      NUMBER ON SUBSTITUTE FORM W-9 FOR ADDITIONAL DETAILS.

YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU CHECKED THE BOX IN PART 3 OF
                              SUBSTITUTE FORM W-9.

<TABLE>
<S>                                                                <C>
- --------------------------------------------------------------------------------------------------
                      CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER

 I certify under penalties of perjury that a Taxpayer Identification Number has not been issued to
 me, and either (a) that I have mailed or delivered an application to receive a Taxpayer
 Identification Number to the appropriate Internal Revenue Service Center or Social Security
 Administration Office or (b) that I intend to mail or deliver an application in the near future.
 I understand that, notwithstanding the information I provided in Part 3 of the Substitute Form
 W-9, if I do not provide a Taxpayer Identification Number to the Depositary within sixty (60)
 days, the Depositary is required to withhold 31% of all cash payments made to me thereafter until
 I provide a number.
  Signature ______________________________________________________ Date ---------------------
- --------------------------------------------------------------------------------------------------
</TABLE>
<PAGE>   9

                                  INSTRUCTIONS
             FORMING PART OF THE TERMS AND CONDITIONS OF THE OFFER

     1. GUARANTEE OF SIGNATURES.  No signature guarantee is required if either:
(a) this Letter of Transmittal is signed by the registered holder of the Shares
(which term, for purposes hereof, shall include any participant in the
Book-Entry Transfer Facility whose name appears on a security position listing
as the owner of such Shares) tendered hereby exactly as the name of such
registered holder appears on the certificate(s) for such Shares tendered with
this Letter of Transmittal and payment and delivery are to be made directly to
such owner unless such owner has completed the box entitled "Special Payment
Instructions" or the box entitled "Special Delivery Instructions" above; or (b)
such Shares are tendered for the account of a member firm of a registered
national securities exchange, a member of the National Association of Securities
Dealers, Inc., or a commercial bank, trust company, savings bank, savings and
loan association or credit union which has a membership in an approved Signature
Guarantee Medallion Program (each of the foregoing constituting an "Eligible
Institution"). In all other cases, an Eligible Institution must guarantee all
signatures on this Letter of Transmittal. See Instruction 5.

     2. DELIVERY OF LETTER OF TRANSMITTAL AND CERTIFICATES; GUARANTEED DELIVERY
PROCEDURES.  This Letter of Transmittal is to be completed only if certificates
for Shares are delivered with it to the Depositary (or such certificates will be
delivered pursuant to a Notice of Guaranteed Delivery previously sent to the
Depositary) or if a tender for Shares is being made concurrently pursuant to the
procedure for tender by book-entry transfer set forth in Section 3 of the Offer
to Purchase. Certificates for all physically tendered Shares or confirmation of
a book-entry transfer into the Depositary's account at the Book-Entry Transfer
Facility of Shares tendered electronically, together in each case with a
properly completed and duly executed Letter of Transmittal (or a manually signed
facsimile thereof), or an Agent's Message in the case of a book-entry transfer,
and any other documents required by this Letter of Transmittal, should be either
mailed or delivered to the Depositary at the appropriate address set forth
herein and must be received by the Depositary on or before the Expiration Date.

DELIVERY OF DOCUMENTS TO THE BOOK-ENTRY TRANSFER FACILITY IN ACCORDANCE WITH THE
BOOK-ENTRY TRANSFER FACILITY'S PROCEDURES DOES NOT CONSTITUTE DELIVERY TO THE
DEPOSITARY.

     Shareholders whose certificates are not immediately available or who cannot
deliver certificates for their Shares and all other required documents to the
Depositary before the Expiration Date, or whose Shares cannot be delivered on a
timely basis pursuant to the procedures for book-entry transfer, must, in any
such case, tender their Shares by or through any Eligible Institution by
properly completing and duly executing and delivering a Notice of Guaranteed
Delivery (or facsimile thereof) and by otherwise complying with the guaranteed
delivery procedure set forth in Section 3 of the Offer to Purchase. Pursuant to
such procedure, certificates for all physically tendered Shares or book-entry
confirmations, as the case may be, as well as a properly completed and duly
executed Letter of Transmittal (or a manually signed facsimile hereof), or an
Agent's Message in the case of a book-entry transfer, and any other documents
required by this Letter of Transmittal, must be received by the Depositary
within three (3) business days of the date of execution of such Notice of
Guaranteed Delivery, all as provided in Section 3 of the Offer to Purchase. The
Notice of Guaranteed Delivery may be delivered by hand or transmitted by
telegram, facsimile transmission or mail to the Depositary and must include a
signature guarantee by an Eligible Institution in the form set forth therein.
For Shares to be tendered validly pursuant to the guaranteed delivery procedure,
the Depositary must receive the Notice of Guaranteed Delivery on or before the
Expiration Date.

     THE METHOD OF DELIVERY OF ALL DOCUMENTS, INCLUDING CERTIFICATES FOR SHARES,
IS AT THE OPTION AND RISK OF THE TENDERING SHAREHOLDER, AND DELIVERY WILL BE
DEEMED MADE ONLY WHEN ACTUALLY RECEIVED BY THE DEPOSITARY. IF DELIVERY IS BY
MAIL, REGISTERED MAIL WITH RETURN RECEIPT REQUESTED, PROPERLY INSURED, IS
RECOMMENDED. IN ALL CASES, SUFFICIENT TIME SHOULD BE ALLOWED TO ASSURE DELIVERY.
DO NOT MAIL OR DELIVER ANY DOCUMENTS, INCLUDING CERTIFICATES FOR SHARES, TO THE
COMPANY.

     The Company will not accept any alternative, conditional or contingent
tenders, nor will it purchase any fractional Shares, except as expressly
provided in the Offer to Purchase. All tendering shareholders, by execution of
this Letter of Transmittal (or a manually signed facsimile hereof), waive any
right to receive any notice of the acceptance of their tender.

     3. INADEQUATE SPACE.  If the space provided in the box entitled
"Description of Shares Tendered" above is inadequate, the certificate numbers
and/or the number of Shares should be listed on a separate signed schedule and
attached to this Letter of Transmittal.
<PAGE>   10

     4. PARTIAL TENDERS AND UNPURCHASED SHARES. (NOT APPLICABLE TO SHAREHOLDERS
WHO TENDER BY BOOK-ENTRY TRANSFER.) If fewer than all of the Shares evidenced by
any certificate are to be tendered, fill in the number of Shares that are to be
tendered in the column entitled "Number of Shares Tendered" in the box entitled
"Description of Shares Tendered" above. In such case, if any tendered Shares are
purchased, a new certificate for the remainder of the Shares (including any
Shares not purchased) evidenced by the old certificate(s) will be issued and
sent to the registered holder(s) thereof, unless otherwise specified in either
the box entitled "Special Payment Instructions" or the box entitled "Special
Delivery Instructions" in this Letter of Transmittal, as soon as practicable
after the Expiration Date. Unless otherwise indicated, all Shares represented by
the certificate(s) set forth above and delivered to the Depositary will be
deemed to have been tendered.

     5. SIGNATURES ON LETTER OF TRANSMITTAL; STOCK POWERS AND ENDORSEMENTS.

     (a) If this Letter of Transmittal is signed by the registered holder(s) of
the Shares tendered hereby, the signature(s) must correspond exactly with the
name(s) as written on the face of the certificate(s) without any alteration or
change whatsoever.

     (b) If any of the Shares tendered hereby are registered in the names of two
or more joint holders, each such holder must sign this Letter of Transmittal.

     (c) If any of the Shares tendered hereby are registered in different names
on several certificates, it will be necessary to complete, sign and submit as
many separate Letters of Transmittal (or manually signed facsimiles hereof) as
there are different registrations of certificates.

     (d) When this Letter of Transmittal is signed by the registered holder(s)
of the Shares tendered hereby, no endorsement(s) of certificate(s) representing
such Shares or separate stock power(s) are required unless payment is to be made
or the certificate(s) for Shares not tendered or not purchased are to be issued
to a person other than the registered holder(s) thereof. Signature(s) on such
certificate(s) must be guaranteed by an Eligible Institution. If this Letter of
Transmittal is signed by a person other than the registered holder(s) of the
certificate(s) listed, or if payment is to be made or certificate(s) for Shares
not tendered or not purchased are to be issued to a person other than the
registered holder(s) thereof, such certificate(s) must be endorsed or
accompanied by appropriate stock power(s), in either case signed exactly as the
name(s) of the registered holder(s) appears on the certificate(s), and the
signature(s) on such certificate(s) or stock power(s) must be guaranteed by an
Eligible Institution. See Instruction 1.

     (e) If this Letter of Transmittal or any certificate(s) or stock power(s)
are signed by a trustee, executor, administrator, guardian, attorney-in-fact,
officer of a corporation or any other person acting in a fiduciary or
representative capacity, such person should so indicate when signing this Letter
of Transmittal and must submit proper evidence satisfactory to the Company of
their authority to so act.

     6. STOCK TRANSFER TAXES.  Except as provided in this Instruction 6, no
stock transfer tax stamps or funds to cover such stamps need accompany this
Letter of Transmittal. The Company will pay or cause to be paid any stock
transfer taxes payable on the transfer to it of Shares purchased pursuant to the
Offer. If, however, either (a) payment of the Purchase Price for Shares tendered
hereby and accepted for purchase is to be made to any person other than the
registered holder(s), or (b) Shares not tendered or not accepted for purchase
are to be registered in the name(s) of any person(s) other than the registered
holder(s) or (c) certificate(s) representing tendered Shares are registered in
the name(s) of any person(s) other than the person(s) signing this Letter of
Transmittal, then the Depositary will deduct from such Purchase Price the amount
of any stock transfer taxes (whether imposed on the registered holder(s), such
other person(s), or otherwise) payable on account of the transfer to such
person, unless satisfactory evidence of the payment of such taxes or any
exemption therefrom is submitted.
<PAGE>   11

     7. ODD LOTS.  As described in Section 1 of the Offer to Purchase, if the
Company is to purchase fewer than all Shares validly tendered before the
Expiration Date and not withdrawn, the Shares purchased first will consist of
all Shares validly tendered by any shareholder who owned, beneficially or of
record, as of the close of business on December 20, 1999, and as of the
Expiration Date, an aggregate of fewer than 100 Shares (not including any Shares
held pursuant to the Company's employee stock ownership plan or 401(k) plan),
and who validly tenders all of such holder's Shares (an "Odd Lot Holder"). This
preference will not be available unless the box captioned "Odd Lots" in this
Letter of Transmittal is completed.

     8. SPECIAL PAYMENT AND DELIVERY INSTRUCTIONS.  If certificate(s) for Shares
not tendered or not purchased and/or check(s) are to be issued in the name of a
person other than the signer of this Letter of Transmittal or if such
certificates and/or checks are to be sent to someone other than the person
signing this Letter of Transmittal or to the signer at a different address, the
box entitled "Special Payment Instructions" and/or the box entitled "Special
Delivery Instructions" on this Letter of Transmittal should be completed as
applicable and signatures must be guaranteed as described in Instruction 1.

     9. IRREGULARITIES.  All questions as to the number of Shares to be accepted
and the validity, form, eligibility (including time of receipt) and acceptance
for payment of any tender of Shares will be resolved by the Company (or by its
representatives, including the Depositary), in its sole discretion, which
determination shall be final and binding on all parties. The Company reserves
the absolute right to reject any or all tenders of Shares it determines not to
be in proper form or the acceptance of which or payment for which may, in the
opinion of the Company's counsel, be unlawful. The Company also reserves the
absolute right to waive any of the conditions of the Offer or any defect or
irregularity in any tender with respect to any particular Shares or any
particular shareholder, and the Company's interpretation of the terms of the
Offer (including these Instructions) will be final and binding on all parties.
No tender of Shares will be deemed to be validly made until all defects and
irregularities have been cured by the tendering shareholder or waived by the
Company. Unless waived, any defects or irregularities in connection with tenders
must be cured within such time as the Company shall determine. None of the
Company, the Depositary, the Information Agent (as defined in the Offer to
Purchase) or any other person is or will be obligated to give notice of any
defects or irregularities in tenders and none of them will incur any liability
for failure to give any such notice. Tenders will not be deemed to have been
made until all defects and irregularities have been cured or waived.

     10. QUESTIONS AND REQUESTS FOR ASSISTANCE AND ADDITIONAL COPIES.  Questions
and requests for assistance may be directed to, or additional copies of the
Offer to Purchase, this Letter of Transmittal, the Notice of Guaranteed Delivery
and other related materials may be obtained from, the Information Agent at its
addresses and telephone numbers set forth on the back cover of the Offer to
Purchase or from brokers, dealers, commercial banks or trust companies.

     11. SUBSTITUTE FORM W-9 AND FORM W-8.  Under the United States federal
income tax backup withholding rules, unless an exemption applies under the
applicable law and regulations, 31% of the gross proceeds payable to a
shareholder or other payee pursuant to the Offer must be withheld and remitted
to the United States Treasury, unless the shareholder or other payee provides
such person's taxpayer identification number (employer identification number or
social security number) to the Depositary and certifies that such number is
correct. Therefore, each tendering shareholder should complete and sign the
Substitute Form W-9 included as part of this Letter of Transmittal so as to
provide the information and certification necessary to avoid backup withholding,
unless such shareholder otherwise establishes to the satisfaction of the
Depositary that it is not subject to backup withholding. Certain shareholders
(including, among others, all corporations and certain foreign shareholders (in
addition to foreign corporations) are not subject to these backup withholding
and reporting requirements. In order for a foreign shareholder to qualify as an
exempt recipient, that shareholder must submit an IRS Form W-8 or a Substitute
Form W-8, signed under penalties of perjury, attesting to that shareholder's
exempt status. Such statements may be obtained from the Depositary.
<PAGE>   12

     12. WITHHOLDING ON FOREIGN SHAREHOLDERS.  Even if a foreign shareholder (as
defined below) has provided the required certification to avoid backup
withholding, the Depositary will withhold United States federal income taxes
equal to 30% of the gross payments payable to a foreign shareholder or such
holder's agent unless the Depositary determines that a reduced rate of
withholding is available pursuant to a tax treaty or that an exemption from
withholding is applicable because such gross proceeds are effectively connected
with the conduct of a trade or business within the United States. For this
purpose, a "foreign shareholder" is any shareholder that for United States
federal income tax purposes is not (a) a citizen or resident of the United
States, (b) a corporation or partnership created or organized in or under the
laws of the United States or any State or division thereof (including the
District of Columbia), (c) an estate the income of which is subject to United
States federal income taxation regardless of the source of such income, or (d) a
trust(i) the administration over which a United States court can exercise
primary supervision and (ii) all of the substantial decisions of which one or
more United States persons have the authority to control. In order to obtain a
reduced rate of withholding pursuant to a tax treaty, a foreign shareholder must
deliver to the Depositary before the payment a properly completed and executed
IRS Form 1001. In order to obtain an exemption from withholding on the grounds
that the gross proceeds paid pursuant to the Offer are effectively connected
with the conduct of a trade or business within the United States, a foreign
shareholder must deliver to the Depositary a properly completed and executed IRS
Form 4224. The Depositary will determine a shareholder's status as a foreign
shareholder and eligibility for a reduced rate of, or an exemption from,
withholding by reference to outstanding certificates or statements concerning
eligibility for a reduced rate of, or exemption from, withholding (e.g., IRS
Form 1001 or IRS Form 4224) unless facts and circumstances indicate that such
reliance is not warranted. A foreign shareholder may be eligible to obtain a
refund of all or a portion of any tax withheld if such foreign shareholder meets
those tests described in Section 13 of the Offer to Purchase that would
characterize the exchange as a sale (as opposed to a dividend) or is otherwise
able to establish that no tax or a reduced amount of tax is due.

     FOREIGN SHAREHOLDERS ARE URGED TO CONSULT THEIR OWN TAX ADVISORS REGARDING
THE APPLICATION OF UNITED STATES FEDERAL INCOME TAX WITHHOLDING, INCLUDING
ELIGIBILITY FOR A WITHHOLDING TAX REDUCTION OR EXEMPTION, AND THE REFUND
PROCEDURE.

     13. LOST, STOLEN, DESTROYED OR MUTILATED CERTIFICATES.  If any
certificate(s) representing Shares has been lost, stolen, destroyed or
mutilated, the shareholder should promptly notify the Information Agent. Such
shareholder will then be instructed by the Information Agent as to the steps
that must be taken in order to replace the certificate. This Letter of
Transmittal and related documents cannot be processed until the procedures for
replacing lost, stolen, destroyed or mutilated certificates have been followed.

     THIS LETTER OF TRANSMITTAL, PROPERLY COMPLETED AND DULY EXECUTED (OR A
MANUALLY SIGNED FACSIMILE HEREOF), TOGETHER WITH CERTIFICATES REPRESENTING
SHARES BEING TENDERED OR CONFIRMATION OF BOOK-ENTRY TRANSFER AND ALL OTHER
REQUIRED DOCUMENTS, OR A NOTICE OF GUARANTEED DELIVERY, MUST BE RECEIVED BY THE
DEPOSITARY PRIOR TO 5:00 P.M. EASTERN TIME, ON THE EXPIRATION DATE.

     The Information Agent for the Offer is: Corporate Investor Communications,
Inc., 111 Commerce Road, Carlstadt, New Jersey 07072-2586, (877) 393-4959.

<PAGE>   1

                                                                  EXHIBIT (A)(3)

                         NOTICE OF GUARANTEED DELIVERY

                                      FOR

                        TENDER OF SHARES OF COMMON STOCK

                                       OF

                             GIANT INDUSTRIES, INC.

            (NOT VALID UNLESS SIGNED BY AN ELIGIBLE INSTITUTION AND
                    NOT TO BE USED FOR SIGNATURE GUARANTEES)

     THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE AT 5:00 P.M.,
        EASTERN TIME, ON FEBRUARY 4, 2000, UNLESS THE OFFER IS EXTENDED.

     This Notice of Guaranteed Delivery, or one substantially in the form
hereof, must be used to accept the Offer (as defined below) if (i) certificates
evidencing shares of common stock, $.01 par value (the "Shares"), of Giant
Industries Inc., a Delaware corporation (the "Company"), are not immediately
available; or (ii) the procedure for book-entry transfer set forth in the Offer
to Purchase (the "Offer to Purchase") and the related Letter of Transmittal
(which, as amended or supplemented from time to time, together constitute the
"Offer") cannot be completed on a timely basis; or (iii) time will not permit
all required documents, including a properly completed and duly executed Letter
of Transmittal (or a manually signed facsimile thereof), to reach the Depositary
prior to the Expiration Date (as defined in the Offer to Purchase).

     This Notice of Guaranteed Delivery, properly completed and duly executed,
may be delivered by hand, mail or facsimile transmission to the Depositary by
the Expiration Date. See Section 3 of the Offer to Purchase.

                TO: HARRIS TRUST AND SAVINGS BANK, AS DEPOSITARY

<TABLE>
<S>                             <C>                             <C>
           By Mail:               By Facsimile Transmission:     By Hand or Overnight Courier:
 Harris Trust and Savings Bank    (for Eligible Institutions     Harris Trust and Savings Bank
   c/o Harris Trust Company                  Only)                 c/o Harris Trust Company
          of New York                   (212) 701-7636                    of New York
      Wall Street Station               (212) 701-7637                  Receive Window
  P.O. Box 1010 New York, New                                     88 Pine Street, 19th Floor
        York 10268-1010              Confirm by Telephone:         New York, New York 10005
                                        (212) 701-7624
</TABLE>

DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OTHER THAN AS SET
FORTH ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA FACSIMILE TRANSMISSION OTHER
THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY. DELIVERIES TO THE
COMPANY WILL NOT BE FORWARDED TO THE DEPOSITARY AND THEREFORE WILL NOT
CONSTITUTE VALID DELIVERY. DELIVERIES TO THE BOOK-ENTRY TRANSFER FACILITY WILL
NOT CONSTITUTE VALID DELIVERY TO THE DEPOSITARY.

     This Notice of Guaranteed Delivery form is not to be used to guarantee
signatures. If a signature on the Letter of Transmittal is required to be
guaranteed by an Eligible Institution (as defined in the Offer to Purchase)
under the instructions thereto, such signature guarantee must appear in the
applicable space provided in the signature box on the Letter of Transmittal.
<PAGE>   2

Ladies and Gentlemen:

     The undersigned hereby tenders to the Company, at a price of $9.00 per
Share, net to the seller in cash, without interest thereon, upon the terms and
subject to the conditions set forth in the Company's Offer to Purchase and the
related Letter of Transmittal, receipt of which is hereby acknowledged, the
number of shares of common stock, $.01 par value, of the Company (the "Shares")
specified below pursuant to the guaranteed delivery procedure set forth in
Section 3 of the Offer to Purchase.

     PLEASE CALL THE INFORMATION AGENT FOR ASSISTANCE IN COMPLETING THIS FORM
TOLL FREE AT (877) 393-4959.

Signature(s):
- --------------------------------------------------------------------------------

Name(s) of Record Holder(s):
        ------------------------------------------------------------------------
                                           (Please type or print)

Certificates Nos.
(if available):
- --------------------------------------------------------------------------------

Address(es):
- --------------------------------------------------------------------------------

- --------------------------------------------------  Zip Code -------------------

Area Code and Telephone No.:
        ------------------------------------------------------------------------

If Shares will be tendered by book-entry transfer, provide the following
information:

Name of Tendering Institution:
      --------------------------------------------------------------------------

Account Number:                                  at The Depository Trust Company
               --------------------------------

Date:-----------------------------------------------

                                    ODD LOTS

     To be completed ONLY if Shares are being tendered by or on behalf of a
person owning beneficially or of record as of the close of business on December
20, 1999, and who continues to own, beneficially or of record, as of the
Expiration Date, an aggregate of fewer than 100 Shares (not including any Shares
held pursuant to the Company's employee stock ownership plan or 401(k) Plan).
The undersigned either (check one box):

     [ ]  was the beneficial or record owner of, as of the close of business on
          December 20, 1999, and continues to own, beneficially or of record as
          of the Expiration Date, an aggregate of fewer than 100 Shares (not
          including any Shares held pursuant to the Company's employee stock
          ownership plan or 401(k) plan), all of which are being tendered; or

     [ ]  is a broker, dealer, commercial bank, trust company, or other nominee
          that (a) is tendering, for the beneficial owner(s) thereof, Shares
          with respect to which it is the record holder, and (b) believes, based
          upon representations made to it by such beneficial owner(s), that each
          such person was the beneficial or record owner of, as of the close of
          business on December 20, 1999, and continues to own beneficially or of
          record as of the Expiration Date, an aggregate of fewer than 100
          Shares (not including any Shares held pursuant to the Company's
          employee stock ownership plan or 401(k) plan) and is tendering all of
          such Shares.

                                        2
<PAGE>   3

                               DELIVERY GUARANTEE
                   (NOT TO BE USED FOR A SIGNATURE GUARANTEE)

     The undersigned, a member firm of a registered national securities
exchange, a member of the National Association of Securities Dealers, Inc., or a
commercial bank, trust company, savings bank, savings and loan association or
credit union which has a membership in an approved Signature Guarantee Medallion
Program (each, an "Eligible Institution"), hereby (i) represents that the
undersigned has a net long position in Shares or equivalent securities within
the meaning of Rule 14e-4 promulgated under the Securities Exchange Act of
1934,as amended, at least equal to the shares tendered, (ii) represents that
such tender of Shares complies with Rule 14e-4, and (iii) guarantees that either
the certificates representing the Shares tendered hereby in proper form for
transfer, or timely confirmation of book-entry transfer of such Shares into the
Depositary's account at The Depository Trust Company (pursuant to the procedures
set forth in Section 3 of the Offer to Purchase), together with a properly
completed and duly executed Letter of Transmittal (or a manually signed
facsimile thereof) with any required signature guarantee, or an Agent's Message
in the case of a book-entry transfer, and any other documents required by the
Letter of Transmittal, will be received by the Depositary at one of its
addresses set forth above within three (3) business days after the date of
execution hereof.

     The Eligible Institution that completes this form must communicate the
guarantee to the Depositary and must deliver the Letter of Transmittal and
certificates representing Shares to the Depositary within the time period set
forth herein. Failure to do so could result in a financial loss to such Eligible
Institution.

<TABLE>
<S>                                           <C>
Name of Firm:
  -----------------------------------
                                              ------------------------------------------
                                              AUTHORIZED SIGNATURE
Address:                                      Name:
- ------------------------------------------    ------------------------------------------
                                              (PLEASE TYPE OR PRINT)
                                              Title:
- ------------------------------------------    ------------------------------------------
ZIP CODE
Area Code and                                 Dated:
                                              ------------------------------------------
Telephone Number:
  ------------------------------
</TABLE>

NOTE:  DO NOT SEND SHARE CERTIFICATES WITH THIS NOTICE. CERTIFICATES FOR SHARES
       SHOULD BE SENT WITH YOUR LETTER OF TRANSMITTAL.

                                        3

<PAGE>   1

                                                                  EXHIBIT (A)(4)

                    CORPORATE INVESTOR COMMUNICATIONS, INC.

                               111 COMMERCE ROAD
                            CARLSTADT, NJ 07072-2586
                                 (877) 393-4959

                             GIANT INDUSTRIES, INC.

                        OFFER TO PURCHASE FOR CASH UP TO
                      1,333,333 SHARES OF ITS COMMON STOCK
                     AT A PURCHASE PRICE OF $9.00 PER SHARE

            THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE
                AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000,
                         UNLESS THE OFFER IS EXTENDED.

To Brokers, Dealers, Commercial Banks,
  Trust Companies and Other Nominees:

     Giant Industries, Inc., a Delaware corporation (the "Company"), has engaged
us to act as Information Agent in connection with its offer to purchase up to
1,333,333 shares (or such lesser number of shares as are validly tendered) of
its common stock, $.01 par value (the "Shares"), at $9.00 per Share, net to the
seller in cash (the "Purchase Price"), without interest thereon, upon the terms
and subject to the conditions set forth in the Offer to Purchase (the "Offer to
Purchase"), and in the related Letter of Transmittal (which, as amended or
supplemented from time to time, together constitute the "Offer").

     The Company will, upon the terms and subject to the conditions of the
Offer, accept for payment, and thereby purchase, up to 1,333,333 Shares validly
tendered and not withdrawn before the Expiration Date (as defined in Section 1
of the Offer to Purchase). All Shares acquired in the Offer will be acquired at
the Purchase Price. In the event more than 1,333,333 Shares are validly tendered
and not withdrawn before the Expiration Date, the Company will accept for
payment, and thereby purchase, Shares, other than Odd Lots, on a pro rata basis
upon the terms and subject to the conditions of the Offer. See Section 1 of the
Offer to Purchase. Shares not purchased because of proration will be returned at
the Company's expense to the shareholders who tendered such Shares as soon as
practicable after the Expiration Date. The Company reserves the right, in its
sole discretion, to purchase more than 1,333,333 Shares pursuant to the Offer.
See Sections 1 and 14 of the Offer to Purchase.

     Upon the terms and subject to the conditions of the Offer, if at the
Expiration Date more than 1,333,333 Shares (or such greater number of Shares as
the Company may elect to purchase) are validly tendered and not withdrawn, the
Company will buy Shares first from any person (an "Odd Lot Holder") who owned
beneficially or of record as of the close of business on December 20, 1999 and
who continues to own beneficially or of record as of the Expiration Date, an
aggregate of fewer than 100 Shares (not including any Shares held pursuant to
the Company's employee stock option plan or 401(k) plan), who validly tender all
their Shares, and then on a pro rata basis from all other shareholders who
validly tender Shares (and do not withdraw such Shares prior to the Expiration
Date).

     THE OFFER IS NOT CONDITIONED ON ANY MINIMUM NUMBER OF SHARES BEING
TENDERED. THE OFFER IS, HOWEVER, SUBJECT TO CERTAIN OTHER CONDITIONS. SEE
SECTION 6 OF THE OFFER TO PURCHASE.
<PAGE>   2

     For your information and for forwarding to those of your clients for whom
you hold Shares registered in your name or in the name of your nominee, we are
enclosing the following documents:

          1. The Offer to Purchase dated December 21, 1999;

          2. The Letter of Transmittal for your use and for the information of
     your clients (together with the accompanying Substitute Form W-9).
     Facsimile copies of the Letter of Transmittal may be used to tender Shares;

          3. A letter to the shareholders of the Company from James E. Acridge,
     Chief Executive Officer and President of the Company;

          4. The Notice of Guaranteed Delivery to be used to accept the Offer
     and tender Shares pursuant to the Offer if none of the procedures for
     tendering Shares set forth in the Offer to Purchase can be completed on a
     timely basis;

          5. A printed form of letter which may be sent to your clients for
     whose accounts you hold Shares registered in your name or in the name of
     your nominee, with an instruction form provided for obtaining such clients'
     instructions with regard to the Offer;

          6. Guidelines of the Internal Revenue Service for Certification of
     Taxpayer Identification Number on Substitute Form W-9; and

          7. A return envelope addressed to Harris Trust and Savings Bank, as
     Depositary for the Offer (the "Depositary").

     YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS AS
     PROMPTLY AS POSSIBLE. PLEASE NOTE THAT THE OFFER, PRORATION PERIOD AND
     WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4,
     2000, UNLESS THE OFFER IS EXTENDED.

     In order to take advantage of the Offer, a duly executed and properly
completed Letter of Transmittal (or a manually signed facsimile thereof)
including any required signature guarantees and any other required documents
should be sent to the Depositary together with either certificate(s)
representing tendered Shares or timely confirmation of their book-entry
transfer, as in accordance with the instructions set forth in the Offer to
Purchase and the related Letter of Transmittal.

     Holders of Shares whose certificate(s) for such Shares are not immediately
available or who cannot deliver such certificate(s) and all other required
documents to the Depositary, or complete the procedures for book-entry transfer,
prior to the Expiration Date must tender their Shares according to the procedure
for guaranteed delivery set forth in Section 3 of the Offer to Purchase.

     No fees or commissions will be payable by the Company or any officer,
director, shareholder, agent or other representative of the Company to any
broker, dealer or other person for soliciting tenders of Shares pursuant to the
Offer (other than fees paid to us, acting as Information Agent).

     The Company will, however, upon request, reimburse you for reasonable and
customary mailing and handling expenses incurred by you in forwarding any of the
enclosed materials to your clients whose Shares held by you as a nominee or in a
fiduciary capacity. The Company will pay any stock transfer taxes applicable to
its purchase of Shares, except as otherwise provided in the Letter of
Transmittal.

                                        2
<PAGE>   3

     No broker, dealer, bank, trust company or fiduciary shall be deemed to be
an agent of the Company, us as "Information Agent", or Harris Trust and Savings
Bank as "Depositary," for purposes of the Offer. Any inquiries you may have with
respect to the Offer should be addressed to Corporate Investor Communications,
Inc., 111 Commerce Road, Carlstadt, New Jersey 07072-2586; (877) 393-4959.
Requests for additional copies of the enclosed materials may be directed to the
Information Agent at the address and telephone number set forth above.

                                          Very truly yours,

                                          Corporate Investor Communications,
                                          Inc.

Enclosures

NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU OR
ANY OTHER PERSON AS AN AGENT OF THE COMPANY, THE INFORMATION AGENT OR THE
DEPOSITARY OR ANY AFFILIATE OF ANY OF THE FOREGOING, OR AUTHORIZE YOU OR ANY
OTHER PERSON TO USE ANY DOCUMENT OR MAKE ANY STATEMENT ON BEHALF OF ANY OF THEM
IN CONNECTION WITH THE OFFER OTHER THAN THE DOCUMENTS ENCLOSED HEREWITH AND THE
STATEMENTS CONTAINED THEREIN.

                                        3

<PAGE>   1

                                                                  EXHIBIT (A)(5)

                             GIANT INDUSTRIES, INC.

                        OFFER TO PURCHASE FOR CASH UP TO
                      1,333,333 SHARES OF ITS COMMON STOCK
                     AT A PURCHASE PRICE OF $9.00 PER SHARE

            THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE
                AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000,
                         UNLESS THE OFFER IS EXTENDED.

To Our Clients:

     Enclosed for your consideration are the Offer to Purchase (the "Offer to
Purchase") and the related Letter of Transmittal (which, as amended or
supplemented from time to time, together constitute the "Offer") in connection
with the offer by Giant Industries, Inc., a Delaware corporation (the
"Company"), to purchase up to 1,333,333 shares (or such lesser number of shares
of common stock as are validly tendered) of its common stock, $.01 par value
(the "Shares"), at $9.00 per Share, net to the seller in cash (the "Purchase
Price"), without interest thereon, upon the terms and subject to the conditions
of the Offer.

     The Company will, upon the terms and subject to the conditions of the
Offer, accept for payment, and thereby purchase, up to 1,333,333 Shares validly
tendered and not withdrawn before the Expiration Date (as defined in Section 1
of the Offer to Purchase). All Shares acquired in the Offer will be acquired at
the Purchase Price. In the event more than 1,333,333 Shares are validly tendered
and not withdrawn before the Expiration Date, the Company will accept for
payment, and thereby purchase, Shares, other than Odd Lots, on a pro rata basis
upon the terms and subject to the conditions of the Offer. See Section 1 of the
Offer to Purchase. Shares not purchased because of proration will be returned at
the Company's expense to the shareholders who tendered such Shares as soon as
practicable after the Expiration Date. The Company reserves the right, in its
sole discretion, to purchase more than 1,333,333 Shares pursuant to the Offer.
See Sections 1 and 14 of the Offer to Purchase.

     Upon the terms and subject to the conditions of the Offer, if at the
Expiration Date more than 1,333,333 Shares (or such greater number of Shares as
the Company may elect to purchase) are validly tendered and not withdrawn, the
Company will buy Shares first from any person (an "Odd Lot Holder") who owned
beneficially or of record as of the close of business on December 20, 1999, and
who continues to own beneficially or of record as of the Expiration Date, an
aggregate of fewer than 100 Shares (not including any Shares held pursuant to
the Company's employee stock ownership plan or 401(k) plan), who validly tender
all their Shares and then on a pro rata basis from all other shareholders who
validly tender Shares (and do not withdraw such Shares prior to the Expiration
Date).

     WE ARE THE OWNER OF RECORD OF SHARES HELD FOR YOUR ACCOUNT. AS SUCH, A
TENDER OF YOUR SHARES CAN BE MADE ONLY BY US AS THE HOLDER OF RECORD THEREOF AND
PURSUANT TO YOUR INSTRUCTIONS. THE LETTER OF TRANSMITTAL IS FURNISHED TO YOU FOR
YOUR INFORMATION ONLY AND CANNOT BE USED BY YOU TO TENDER YOUR SHARES HELD BY US
FOR YOUR ACCOUNT.

     Accordingly, please instruct us as to whether you wish to tender any or all
of the Shares held by us for your account, upon the terms and subject to the
conditions of the Offer.

     We call your attention to the following:

          1. Shares will be tendered at $9.00 per Share, as indicated in the
     attached Instruction Form, net to the seller in cash, without interest
     thereon.
<PAGE>   2

          2. The Offer is not conditioned on any minimum number of Shares being
     tendered. The Offer is, however, subject to certain other conditions set
     forth in the Offer to Purchase.

          3. The Offer, proration period and withdrawal rights will expire at
     5:00 p.m., Eastern Time, on February 4, 2000, unless the Offer is extended
     by the Company.

          4. The Offer is for 1,333,333 Shares, constituting approximately 12.9%
     of the Shares outstanding as of December 20, 1999.

          5. The members of the Board of Directors of the Company who met to
     approve the offer have unanimously approved the Offer. Notwithstanding the
     foregoing, neither the Company nor its Board of Directors makes any
     recommendation to shareholders as to whether to tender or refrain from
     tendering their Shares. Shareholders must individually make the decision
     whether to tender such shareholder's Shares and, if so, how many Shares to
     tender.

          6. Tendering shareholders will not be obligated to pay any stock
     transfer taxes on the Company's purchase of Shares pursuant to the Offer,
     subject to Instruction 6 of the Letter of Transmittal.

          7. Tendering shareholders will not be obligated to pay any brokerage
     fees or commissions or solicitation fees to the Depositary or the Company.

          8. If (i) you owned beneficially or of record as of the close of
     business on December 20, 1999, and continue to own beneficially or of
     record as of the Expiration Date, an aggregate of fewer than 100 Shares
     (not including any shares held pursuant to the Company's employee stock
     ownership plan or 401(k) plan); (ii) you instruct us to tender on your
     behalf all such Shares prior to the Expiration Date; and (iii) you complete
     the section entitled "Odd Lots" in the attached Instruction Form, the
     Company, upon the terms and subject to the conditions of the Offer, will
     accept all such Shares for purchase before proration, if any, of the
     purchase of other Shares validly tendered.

     If you wish to have us tender any or all of your Shares, please so instruct
us by completing, executing, detaching and returning to us the attached
Instruction Form. An envelope to return your Instruction Form to us is enclosed.
If you authorize us to tender your Shares, all such Shares will be tendered
unless otherwise indicated on the attached Instruction Form.

     PLEASE FORWARD YOUR INSTRUCTION FORM TO US AS SOON AS POSSIBLE TO ALLOW US
AMPLE TIME TO TENDER YOUR SHARES ON YOUR BEHALF PRIOR TO THE EXPIRATION DATE OF
THE OFFER. THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE AT 5:00
P.M., EASTERN TIME, ON FEBRUARY 4, 2000, UNLESS THE COMPANY EXTENDS THE OFFER.

     As described in Section 1 of the Offer to Purchase, if more than 1,333,333
Shares (or such greater number of Shares as the Company may elect to purchase)
have been validly tendered and not withdrawn prior to the Expiration Date, the
Company will accept for payment and therefore purchase tendered Shares on the
basis set forth below:

          1. first, all Shares validly tendered and not withdrawn prior to the
     Expiration Date by any Odd Lot Holder who:

             (a) tenders all Shares owned beneficially or of record by such Odd
        Lot Holder (not including any Shares held pursuant to the Company's
        employee stock ownership plan or 401(k) Plan tenders of less than all
        Shares owned by such Odd Lot Holder will not qualify for this
        preference); and

             (b) completes the box captioned "Odd Lots" in the attached
        Instruction Form and, if applicable, on the Notice of Guaranteed
        Delivery; and

          2. second, after purchase of all of the foregoing Shares, all other
     Shares validly tendered and not withdrawn prior to the Expiration Date, on
     a pro rata basis as described in Section 1 of the Offer to Purchase.

                                        2
<PAGE>   3

     The Offer is being made solely pursuant to the Offer to Purchase and the
related Letter of Transmittal and is being made to all holders of Shares. The
Offer is not being made to, nor will tenders be accepted from or on behalf of,
holders of Shares residing in any jurisdiction in which the making of the Offer
or acceptance thereof would not be in compliance with the securities laws of
such jurisdiction. If the Company becomes aware of any jurisdiction where the
making of the Offer is not in compliance with any valid applicable law, the
Company will make a good faith effort to comply with such law. If, after such
good faith effort, the Company cannot comply with such law, the Offer will not
be made to, nor will tenders be accepted from or on behalf of, holders of Shares
residing in such jurisdiction. In any jurisdiction the securities or blue sky
laws of which require the Offer to be made by a licensed broker or dealer, the
Offer is being made on the Company's behalf by one or more registered brokers or
dealers licensed under the laws of such jurisdiction.

                                INSTRUCTION FORM
             FOR SHARES HELD BY BROKERS, DEALERS, COMMERCIAL BANKS,
                       TRUST COMPANIES AND OTHER NOMINEES

                      INSTRUCTIONS FOR TENDER OF SHARES OF
                             GIANT INDUSTRIES, INC.

     The undersigned acknowledge(s) receipt of your letter and the enclosed
Offer to Purchase (the "Offer to Purchase") and the related Letter of
Transmittal (which, as amended or supplemented from time to time, together
constitute the "Offer") in connection with the offer by Giant Industries, Inc.,
a Delaware corporation (the "Company"), to purchase up to 1,333,333 shares (or
such lesser number of shares as are validly tendered) of its common stock, $.01
par value (the "Shares"), at $9.00 per Share, net to the seller in cash, without
interest thereon, upon the terms and subject to the conditions of the Offer.

     This will instruct you to tender to the Company, on (our) (my) behalf, the
number of Shares indicated below (or if no number is indicated below, all
Shares) which are beneficially owned by (us) (me) and registered in your name,
upon terms and subject to the conditions of Offer.

                NUMBER OF SHARES TO BE TENDERED: ______ SHARES*

 *Unless otherwise indicated, it will be assumed that all Shares held by us for
                        your account are to be tendered.

                                    ODD LOTS

     [ ] By checking this box the undersigned represents that the undersigned
         owned beneficially or of record as of the close of business on December
         20, 1999, and continues to own, beneficially or of record as of the
         Expiration Date, an aggregate of fewer than 100 Shares (not including
         any Shares held pursuant to the Company's employee stock ownership plan
         and 401(k) Plan) and is tendering all of such Shares.

                                        3
<PAGE>   4

THE METHOD OF DELIVERY OF THIS DOCUMENT IS AT THE OPTION AND RISK OF THE
TENDERING SHAREHOLDER. IF DELIVERY IS BY MAIL, REGISTERED MAIL WITH RETURN
RECEIPT REQUESTED, PROPERLY INSURED, IS RECOMMENDED. IN ALL CASES, SUFFICIENT
TIME SHOULD BE ALLOWED TO ASSURE DELIVERY.

                                   SIGN HERE:

Signature(s):
- --------------------------------------------------------------------------------

Print Name(s):
- --------------------------------------------------------------------------------

Address(es):
- --------------------------------------------------------------------------------
                              (INCLUDING ZIP CODE)

Telephone Number:
- --------------------------------------------------------------------------------

Taxpayer Identification or Social Security Number:
                            ----------------------------------------------------

Date:
- --------------------------------------------------------------------------------

IMPORTANT: SHAREHOLDERS ARE ENCOURAGED TO RETURN A COMPLETED FORM W-9 WITH THEIR
INSTRUCTION FORM.

                                        4

<PAGE>   1

                                                                  EXHIBIT (A)(6)

                             GIANT INDUSTRIES, INC.

                               DECEMBER 21, 1999

Dear Shareholders:

     One of the primary goals at Giant Industries, Inc. is to enhance
shareholder value. After evaluating a variety of alternatives, we have
determined that a repurchase of our own shares of common stock is one method of
achieving this goal that we can currently implement.

     The Company's Board of Directors has reviewed the Company's financial
condition and outlook as well as current market conditions, including the recent
trading prices of shares of our common stock, and believes this is an attractive
time to repurchase outstanding shares of our common stock. As a result, the
members of the Board of Directors who met to approve the repurchase unanimously
approved a repurchase of up to 1,333,333 shares of the Company's common stock,
or approximately 12.9% of our 10,303,488 outstanding shares, from its
shareholders through a tender offer at a purchase price of $9.00 per share, net
to the seller in cash.

     This tender offer provides the shareholders the opportunity to sell shares
of common stock for cash without the usual transaction costs. A copy of the
Offer to Purchase is enclosed.

     This tender offer is explained in detail in the enclosed Offer to Purchase
and Letter of Transmittal. If you wish to tender your shares of common stock,
detailed instructions on how to tender shares are also included in the enclosed
materials. We encourage you to read these materials carefully before making any
decision with respect to this tender offer. Neither the Company nor its Board of
Directors makes any recommendation to any shareholder as to whether to tender or
refrain from tendering their shares. You should make your decision independently
after consulting with your advisors.

     To assist us with this tender offer, we have engaged Corporate Investor
Communications, Inc. to serve as Information Agent. If you need information or
additional forms, please call the Information Agent toll free at (877) 393-4959.

     If you are a participant in the Company's employee stock ownership plan,
you may direct the tender of your plan shares by following the special
instructions included from Wells Fargo Bank, N.A., the employee stock ownership
plan trustee. If you are a participant in the Company's 401(k) plan, you may
direct the tender of your plan shares by following the special instructions
included from Fidelity Management Trust Company, the 401(k) plan trustee.

     Unless otherwise extended by the Company, this tender offer will expire at
5:00 p.m., Eastern Time, on February 4, 2000. We again encourage you to
carefully read the enclosed materials.

     As always, we appreciate your continued interest in Giant Industries, Inc.

                                          Sincerely,

                                          /s/ James E. Acridge

                                          James E. Acridge
                                          Chief Executive Officer and President

<PAGE>   1

                                                                  EXHIBIT (A)(7)

            GUIDELINES FOR CERTIFICATION OF TAXPAYER IDENTIFICATION
                         NUMBER ON SUBSTITUTE FORM W-9

GUIDELINES FOR DETERMINING THE PROPER IDENTIFICATION NUMBER TO GIVE THE
PAYER.--Social Security numbers have nine digits separated by two hyphens: i.e.,
000-00-0000. Employer identification numbers have nine digits separated by only
one hyphen: i.e., 00-0000000. The table below will help determine the number to
give the payer.

<TABLE>
<C>  <S>                                 <C>
- ------------------------------------------------------------
                                         GIVE THE NAME AND
              FOR THIS TYPE OF ACCOUNT:  SOCIAL SECURITY
                                         NUMBER OF--
- ------------------------------------------------------------

 1.  Individual                          The individual
 2.  Two or more individuals (joint      The actual owner of
     account)                            the account or, if
                                         combined funds, the
                                         first individual on
                                         the account(1)
 3.  Custodian account of a minor        The minor(2)
     (Uniform Gift to Minors Act)
 4.  a. The usual revocable savings      The grantor-
        trust (grantor is also trustee)  trustee(1)
     b. So-called trust account that is  The actual owner(1)
        not a legal or valid trust
        under state law
 5.  Sole proprietorship                 The owner(3)
- ------------------------------------------------------------
- ------------------------------------------------------------
                                         GIVE THE NAME AND
                                         EMPLOYER
              FOR THIS TYPE OF ACCOUNT:  IDENTIFICATION
                                         NUMBER OF--
- ------------------------------------------------------------

 6.  A valid trust, estate of pension    The legal entity(4)
     trust
 7.  Corporate                           The corporation
 8.  Association, club, religious,       The organization
     charitable, educational or other
     tax-exempt organization
 9.  Partnership                         The partnership
10.  A broker or registered nominee      The broker or
                                         nominee
11.  Account with the Department of      The public entity
     Agriculture in the name of a
     public entity (such as a state or
     local government, school district,
     or prison) that receives
     agricultural program payments
- ------------------------------------------------------------
</TABLE>

(1) List first and circle the name of the person whose number you furnish. If
    only one person on a joint account has a social security number, that
    person's number must be furnished.
(2) Circle the minor's name and furnish the minor's social security number.
(3) You must show your individual name, but you may also enter your business or
    "doing business as" name. You may use either your social security number or
    employer identification number (if you have one).
(4) List first and circle the name of the legal trust, estate, or pension trust.
    (Do not furnish the identifying number of the personal representative or
    trustee unless the legal entity itself is not designated in the account
    title.)

NOTE: If no name is circled when there is more than one name, the number will be
      considered to be that of the first name listed.
<PAGE>   2

OBTAINING A NUMBER
If you don't have a taxpayer identification number or you don't know your
number, obtain Form SS-5, Application for a Social Security Number, or Form
SS-4, Application for an Employer Identification Number, at the local office of
the Social Security Administration or the Internal Revenue Service and apply for
a number. United States resident aliens who cannot obtain a social security
number must apply for an ITIN (Individual Taxpayer Identification Number) on
Form W-7.

PAYEES EXEMPT FROM BACKUP WITHHOLDING
Payees specifically exempted from backup withholding on payments of interest and
dividends and with respect to broker transactions include the following:
  - A corporation.
  - A financial institution.
  - An organization exempt from tax under section 501(a), or an individual
    retirement plan.
  - The United States or any agency or instrumentality thereof.
  - A state, the District of Columbia, a possession of the United States, or any
    political subdivision or instrumentality thereof.
  - A foreign government, or any political subdivision, agency or
    instrumentality thereof.
  - An international organization or any agency or instrumentality thereof.
  - A dealer in securities or commodities required to register in the United
    States, the District of Columbia, or a possession of the United States.
  - A real estate investment trust.
  - A common trust fund operated by a bank under section 584(a).
  - An exempt charitable remainder trust, or a non-exempt trust described in
    section 4947.
  - An entity registered at all times under the Investment Company Act of 1940.
  - A foreign central bank of issue.
  Payments of dividends and patronage dividends not generally subject to backup
withholding include the following:
  - Payments to nonresident aliens subject to withholding under section 1441.
  - Payments to partnerships not engaged in a trade or business in the United
    States and which have at least one nonresident alien partner.
  - Payments of patronage dividends not paid in money.
  - Payments made by certain foreign organizations.
  - Payments made to a middleman known in the investment community as a nominee
    or who is listed in the most recent publication of the American Society of
    Corporate Secretaries, Inc. Nominee List.
  Payments of interest not generally subject to backup withholding include the
following:
  - Payments of interest on obligations issued by individuals. Note: You may be
    subject to backup withholding if this interest is $600 or more and is paid
    in the course of the payer's trade or business and you have not provided
    your correct taxpayer identification number to the payer.
  - Payments of tax-exempt interest (including exempt interest dividends under
    section 852).
  - Payments described in section 6049(b)(5) to nonresident aliens.
  - Payments on tax-free covenant bonds under section 1451.
  - Payments made by certain foreign organizations.
  - Payments made to a middleman known in the investment community as a nominee
    or who is listed in the most recent publication of the American Society of
    Corporate Secretaries, Inc., Nominee List.
Exempt payees described above should file Substitute Form W-9 to avoid possible
erroneous backup withholding. FILE THIS FORM WITH THE PAYER, FURNISH YOUR
TAXPAYER IDENTIFICATION NUMBER, WRITE "EXEMPT" ON THE FACE OF THE FORM, AND
RETURN IT TO THE PAYER. IF THE PAYMENTS ARE INTEREST, DIVIDENDS, OR PATRONAGE
DIVIDENDS, ALSO SIGN AND DATE THE FORM.

PENALTIES
(1) PENALTY FOR FAILURE TO FURNISH TAXPAYER IDENTIFICATION NUMBER.--If you fail
to furnish your taxpayer identification number to a payer, you are subject to a
penalty of $50 for each such failure unless your failure is due to a reasonable
cause and not to willful neglect.
(2) CIVIL PENALTY FOR FALSE INFORMATION WITH RESPECT TO WITHHOLDING.--If you
make a false statement with no reasonable basis which results in no imposition
of backup withholding, you are subject to a penalty of $500.
(3) CRIMINAL PENALTY FOR FALSIFYING INFORMATION.--Willfully falsifying
certifications or affirmations may subject you to criminal penalties including
fines and/or imprisonment.

 FOR ADDITIONAL INFORMATION CONTACT YOUR TAX CONSULTANT OR THE INTERNAL REVENUE
                                    SERVICE

<PAGE>   1

                                                                  EXHIBIT (A)(8)

                           OFFER TO PURCHASE FOR CASH
                   UP TO 1,333,333 SHARES OF ITS COMMON STOCK
                          AT A PURCHASE PRICE OF $9.00

                                       OF

                             GIANT INDUSTRIES, INC.

        THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT
  5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000, UNLESS THE OFFER IS EXTENDED.

To the Participants in the Employee Stock Ownership Plan and Trust of
Giant Industries, Inc. and Affiliated Companies (the "ESOP"):

     Enclosed for your consideration are the Offer to Purchase, dated December
21, 1999 (the "Offer to Purchase"), and the related Letter of Transmittal which
together constitute (the "Offer) setting forth Giant Industries, Inc.'s offer to
purchase up to 1,333,333 shares of its Common Stock (the "Shares") at a purchase
price of $9.00 per share. If you do not wish to direct the sale of the Shares
held in your ESOP account (the "ESOP Shares"), you do not need to take any
action. If you would like to direct the sale of some or all of your ESOP Shares
in response to this Offer, detailed instructions on how to tender are included
in the enclosed materials.

     You must carefully follow the instructions below if you want to direct the
tender of some or all of the Shares held in your ESOP account. Failure to follow
such instructions properly may make you ineligible to direct the tender of such
Shares in the Company's offer. We are the holder of record of the ESOP Shares
held for your account. A tender of such ESOP Shares can be made only by us as
the holder of record. Pursuant to your instructions, we will complete a Letter
of Transmittal with respect to ESOP Shares you direct us, as trustee of the ESOP
(the "ESOP Trustee"), through our agent, U.S. Stock Transfer Corporation (the
"Agent"), to tender on your behalf.

     BECAUSE THE TERMS AND CONDITIONS OF THE LETTER OF TRANSMITTAL WILL GOVERN
THE TENDER OF YOUR ESOP SHARES, YOU SHOULD READ THE LETTER OF TRANSMITTAL
CAREFULLY. THE LETTER OF TRANSMITTAL IS, HOWEVER, FURNISHED TO YOU FOR YOUR
INFORMATION ONLY AND CANNOT BE USED BY YOU TO TENDER ESOP SHARES HELD BY US FOR
YOUR ACCOUNT.

     ESOP Shares that are not purchased in the Company's offer because of the
proration process as described below and in the Offer to Purchase (or for any
other reason) will remain in or be returned to your applicable ESOP account. We
request instructions, through the Agent, as to whether you wish us to tender any
or all of the Shares held by us for your account, upon the terms and subject to
the conditions set forth in the Offer to Purchase and the Letter of Transmittal.
Your attention is invited to the following:

          (1) You may direct the tender of Shares at a price of $9.00, as
     indicated in the attached Instruction Form, net to the seller in cash,
     without interest thereon.

          (2) The Offer is for up to 1,333,333 Shares, constituting
     approximately 12.9% of the total Shares outstanding as of December 20,
     1999. Although it has no present intention of so doing, the Company
     reserves the right to purchase more or less than 1,333,333 Shares pursuant
     to the Offer. The Offer is not conditioned upon any minimum number of
     Shares being tendered. The Offer is, however, conditional on other factors.

          (3) The Offer, proration period and withdrawal rights will expire at
     5:00 P.M., Eastern Time, on February 4, 2000, unless the Offer is extended.
     SHOULD YOU WISH TO DIRECT THE TENDER OF ALL OR ANY OF YOUR ESOP SHARES, YOU
     SHOULD INSTRUCT US OF YOUR
<PAGE>   2

     INTENTIONS IN AMPLE TIME TO PERMIT US TO SUBMIT A TENDER ON YOUR BEHALF AND
     IN ANY EVENT NO LATER THAN 5:00 P.M. ON JANUARY 27, 2000. If you would like
     to direct the withdrawal from the tender of your ESOP Shares that we have
     tendered, you can do so as long as the Offer remains open or at any time
     after February 17, 2000 if they have not been accepted for payment.

          (4) As described in the Offer to Purchase, if more than 1,333,333
     Shares have been validly tendered at the Purchase Price and not properly
     withdrawn on or prior to the Expiration Date, as defined in Section 1 of
     the Offer to Purchase, the Company will prorate the number of Shares it
     purchases from each person who tenders Shares. This means that the Company
     will not purchase all of the ESOP Shares that you directed to be tendered
     under these circumstances. In the event of proration, the Company will
     purchase Shares in the following order of priority:

             (a) all Shares validly tendered at the Purchase Price and not
        properly withdrawn on or prior to the Expiration Date by any stockholder
        (an "Odd Lot Owner") who owned beneficially or of record an aggregate of
        fewer than 100 Shares (not including any Shares held pursuant to the
        Company's ESOP Plan or 401(k) Plan) as of the close of business on
        December 20, 1999, if such stockholder tenders all of his or her Shares;
        and

             (b) after purchase of all of the foregoing Shares, all other Shares
        (including any ESOP Shares or 401(k) Shares) validly tendered at the
        Purchase Price and not properly withdrawn on or prior to the Expiration
        Date on a pro rata basis, if necessary (with appropriate rounding
        adjustments to avoid purchases of fractional Shares);

          (5) Any stock transfer taxes applicable to the sale of Shares to the
     Company pursuant to the Offer will be paid by the Company, except as
     otherwise provided in Instruction 6 of the Letter of Transmittal.

          (6) Tendering stockholders will not be obligated to pay any brokerage
     commissions, solicitation fees or, subject to Instruction 6 of the Letter
     of Transmittal, stock transfer taxes on the Company's purchase of Shares
     pursuant to the Offer.

          (7) If you wish to direct the tender of all or a portion of your ESOP
     Shares, you must notify the Agent on our behalf. We must submit a Letter of
     Transmittal.

     NEITHER THE COMPANY NOR ITS BOARD OF DIRECTORS MAKES ANY RECOMMENDATION TO
ANY STOCKHOLDER AS TO WHETHER TO TENDER ALL OR ANY SHARES. STOCKHOLDERS MUST
MAKE THEIR OWN DECISION AS TO WHETHER TO TENDER SHARES AND, IF SO, HOW MANY
SHARES TO TENDER.

     The Offer is being made to all holders of Shares solely pursuant to the
Offer to Purchase and the related Letter of Transmittal. This Offer is not being
made to (nor will any tender of Shares be accepted from or on behalf of) holders
in any jurisdiction in which the making of the Offer or the acceptance of any
tender of Shares therein would not be in compliance with the laws of such
jurisdiction. The Company may, at its discretion, take such action as it may
deem necessary for the Company to make the Offer in any such jurisdiction and
extend the Offer to holders in such jurisdiction. In any jurisdiction the
securities or blue sky laws of which require the Offer to be made by a licensed
broker or dealer, the Offer is being made on behalf of the Company by one or
more registered brokers or dealers which are licensed under the laws of such
jurisdiction.

     IN ORDER TO DIRECT THE TENDER OF ESOP SHARES, YOU MUST COMPLETE, EXECUTE,
DETACH AND RETURN THE ATTACHED INSTRUCTION FORM TO THE AGENT IN AMPLE TIME TO
PERMIT US TO SUBMIT A TENDER ON YOUR BEHALF BY THE EXPIRATION OF THE OFFER AND
IN ANY EVENT NO LATER THAN 5:00 P.M., EASTERN TIME, ON JANUARY 27, 2000. THE
OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS EXPIRE AT 5:00 P.M., EASTERN TIME,
ON FEBRUARY 4, 2000, UNLESS THE COMPANY EXTENDS THE OFFER. SHARES THAT ARE
TENDERED AFTER THIS DEADLINE, AND SHARES THAT ARE OTHERWISE INVALIDLY TENDERED,
WILL NOT BE ACCEPTED.

                                        2
<PAGE>   3

AN ENVELOPE TO RETURN YOUR INSTRUCTION FORM TO THE AGENT IS ENCLOSED. IF YOU
DIRECT US, THROUGH THE AGENT, TO TENDER YOUR ESOP SHARES, ALL SUCH SHARES WILL
BE TENDERED UNLESS OTHERWISE INDICATED ON THE ATTACHED INSTRUCTION FORM.

     As more fully described in the Offer to Purchase, tenders will be deemed
irrevocable unless withdrawn by the dates specified therein. If you instruct the
ESOP Trustee, through the Agent, to tender ESOP Shares, and you subsequently
decide to change your instructions, you may do so by submitting a written notice
of change of instruction to the Agent. The notice of change of instruction will
be effective only if it is received by the Agent AT OR BEFORE 5:00 P.M., EASTERN
TIME, ON JANUARY 27, 2000. Upon receipt of a timely notice of change of
instruction to the Agent, previous instructions to tender with respect to such
Shares will be deemed canceled. If you later wish to re-tender Shares, you may
call the Agent at the above number and submit a new Instruction Form. If you
have any questions about the Offer or any of the other matters discussed above,
please call Corporate Investor Communications, Inc., the Information Agent, at
(877) 393-4959.

                                          Sincerely,

                                          Wells Fargo Bank, N.A.

                                        3
<PAGE>   4

                                INSTRUCTION FORM
             FOR SHARES HELD BY WELLS FARGO BANK, N.A., AS TRUSTEE
    OF THE EMPLOYEE STOCK OWNERSHIP PLAN AND TRUST OF GIANT INDUSTRIES, INC.
                            AND AFFILIATED COMPANIES

                      INSTRUCTIONS FOR TENDER OF SHARES OF

                             GIANT INDUSTRIES, INC.

        THIS FORM IS TO BE RETURNED TO U.S. STOCK TRANSFER CORPORATION,
        THE AGENT (THE "AGENT") OF WELLS FARGO BANK, N.A. AN ENVELOPE TO
             RETURN THIS INSTRUCTION FORM TO THE AGENT IS ENCLOSED.

     The undersigned acknowledge(s) receipt of the letter from Wells Fargo Bank,
N.A., as trustee of the ESOP Plan, and the related Letter of Transmittal (which,
as amended or supplemented from time to time, together constitute the "Offer")
in connection with the offer by Giant Industries, Inc., a Delaware corporation
(the "Company"), to purchase up to 1,333,333 shares (or such lesser number of
shares as are validly tendered) of its common stock, $.01 par value (the
"Shares"), at $9.00 per Share, net to the seller in cash, without interest
thereon, upon the terms and subject to the conditions of the Offer.

     This will instruct you to tender to the Company, on (our) (my) behalf, the
number of ESOP Shares indicated below (or if no percentage is indicated below,
all ESOP Shares) which are allocated to my ESOP account, upon the terms and
subject to the conditions of Offer.

        NUMBER OF ESOP SHARES TO BE TENDERED: ____________ ESOP SHARES*

      *Unless otherwise indicated, it will be assumed that all ESOP Shares
                 allocated to your account are to be tendered.

THE METHOD OF DELIVERY OF THIS DOCUMENT IS AT THE OPTION AND RISK OF THE
TENDERING ESOP SHAREHOLDER. IF DELIVERY IS BY MAIL, REGISTERED MAIL WITH RETURN
RECEIPT REQUESTED, PROPERLY INSURED, IS RECOMMENDED. IN ALL CASES, SUFFICIENT
TIME SHOULD BE ALLOWED TO ASSURE DELIVERY.

                                   SIGN HERE:

Signature(s):
- --------------------------------------------------------------------------------

Print Name(s):
- --------------------------------------------------------------------------------

Address(es):
- --------------------------------------------------------------------------------
                              (INCLUDING ZIP CODE)

Telephone Number:
- --------------------------------------------------------------------------------

Taxpayer Identification or Social Security Number:
- --------------------------------------------------------------------------------

Date:
- --------------------------------------------------------------------------------

<PAGE>   1

                                                                  EXHIBIT (A)(9)

                           OFFER TO PURCHASE FOR CASH

                   UP TO 1,333,333 SHARES OF ITS COMMON STOCK
                          AT A PURCHASE PRICE OF $9.00

                                       OF

                             GIANT INDUSTRIES, INC.

         THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE
                AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000,
                         UNLESS THE OFFER IS EXTENDED.

To the Participants in the Giant Industries, Inc. and
Affiliated Companies 401(k) Plan and Trust (the "401(k) Plan"):

     Enclosed for your consideration are the Offer to Purchase, dated December
21, 1999 (the "Offer to Purchase"), and the related Letter of Transmittal which
together constitute (the "Offer) setting forth Giant Industries, Inc.'s offer to
purchase up to 1,333,333 shares of its Common Stock (the "Shares") at a purchase
price of $9.00 per share. If you do not wish to direct the sale of any portion
of the Shares reflected by units of the Stock Fund in your 401(K) Plan account
(the "401(k) Shares"), you do not need to take any action. If you would like to
direct the sale of some or all of such 401(k) Shares in response to this Offer,
detailed instructions on how to tender are included in the enclosed materials.

     You must carefully follow the instructions below if you want to direct the
tender of some or all of the Shares reflected by units of the Stock Fund in your
401(k) Plan account. Failure to follow such instructions properly may make you
ineligible to direct the tender of such Shares in the Company's offer. We are
the holder of record of the 401(k) Shares held by the Stock Fund. A tender of
such 401(k) Shares can be made only by us as the holder of record. Pursuant to
your instructions, we will complete a Letter of Transmittal with respect to
401(k) Shares reflected by your units of the Stock Fund as you direct us, as
trustee of the 401(k) Plan (the "401(k) Plan Trustee"), through our agent,
Management Information Services (the "Agent"), to tender on your behalf.

     BECAUSE THE TERMS AND CONDITIONS OF THE LETTER OF TRANSMITTAL WILL GOVERN
THE TENDER OF THE 401(K) SHARES, YOU SHOULD READ THE LETTER OF TRANSMITTAL
CAREFULLY. THE LETTER OF TRANSMITTAL, HOWEVER, IS FURNISHED TO YOU FOR YOUR
INFORMATION ONLY AND CANNOT BE USED BY YOU TO TENDER 401(K) SHARES HELD BY US IN
THE STOCK FUND.

     401(k) Shares that are not purchased in the Company's offer because of the
proration process as described below and in the Offer to Purchase (or for any
other reason) will remain in or be returned to the Stock Fund. We request
instructions, through the Agent, as to whether you wish us to tender any or all
of the Shares that reflect units of the Stock Fund allocated to your account,
upon the terms and subject to the conditions set forth in the Offer to Purchase
and the Letter of Transmittal. Your attention is invited to the following:

          (1) You may direct the tender of Shares at a price of $9.00.

          (2) The Offer is for up to 1,333,333 Shares, constituting
     approximately 12.9% of the total Shares outstanding as of December 20,
     1999. Although it has no present intention of so doing, the Company
     reserves the right to purchase more or less than 1,333,333 Shares pursuant
     to the Offer. The Offer is not conditioned upon any minimum number of
     Shares being tendered. The Offer is, however, conditional on other factors.
<PAGE>   2

          (3) The Offer, proration period and withdrawal rights will expire at
     5:00 P.M., Eastern Time, on February 4, 2000, unless the Offer is extended.
     SHOULD YOU WISH TO DIRECT THE TENDER OF ALL OR ANY OF YOUR 401(K) SHARES
     THAT REFLECT UNITS OF THE STOCK FUND ALLOCATED TO YOUR ACCOUNT, YOU SHOULD
     INSTRUCT US OF YOUR INTENTIONS IN AMPLE TIME TO PERMIT US TO SUBMIT A
     TENDER ON YOUR BEHALF AND IN ANY EVENT NO LATER THAN 5:00 P.M. ON JANUARY
     27, 1999. If you would like to direct the withdrawal from the tender of the
     401(k) Shares that we have tendered, you can do so as long as the Offer
     remains open or at any time after February 17, 2000 if they have not been
     accepted for payment.

          (4) As described in the Offer to Purchase, if more than 1,333,333
     Shares have been validly tendered at the Purchase Price and not properly
     withdrawn on or prior to the Expiration Date, as defined in Section 1 of
     the Offer to Purchase, the Company will prorate the number of Shares it
     purchases from each person who tenders Shares. This means that the Company
     will not purchase all of the 401(K) Shares that you directed to be tendered
     under these circumstances. In the event of proration, the Company will
     purchase Shares in the following order of priority:

             (a) all Shares validly tendered at the Purchase Price and not
        properly withdrawn on or prior to the Expiration Date by any stockholder
        (an "Odd Lot Owner") who owned beneficially or of record an aggregate of
        fewer than 100 Shares (not including any Shares held pursuant to the
        Company's ESOP Plan or 401(k) Plan) as of the close of business on
        December 20, 1999, if such stockholder tenders all of his or her Shares;
        and

             (b) after purchase of all of the foregoing Shares, all other Shares
        (including any ESOP Shares or 401(k) Shares) validly tendered at the
        Purchase Price and not properly withdrawn on or prior to the Expiration
        Date on a pro rata basis, if necessary (with appropriate rounding
        adjustments to avoid purchases of fractional Shares);

          (5) Any stock transfer taxes applicable to the sale of Shares to the
     Company pursuant to the Offer will be paid by the Company, except as
     otherwise provided in Instruction 6 of the Letter of Transmittal.

          (6) Tendering stockholders will not be obligated to pay any brokerage
     commissions, solicitation fees or, subject to Instruction 6 of the Letter
     of Transmittal, stock transfer taxes on the Company's purchase of Shares
     pursuant to the Offer.

          (7) If you wish to direct the tender of all or a portion of the 401(k)
     Shares, you must notify the Agent on our behalf. We must submit a Letter of
     Transmittal.

     NEITHER THE COMPANY NOR ITS BOARD OF DIRECTORS MAKES ANY RECOMMENDATION TO
ANY STOCKHOLDER AS TO WHETHER TO TENDER ALL OR ANY SHARES. STOCKHOLDERS MUST
MAKE THEIR OWN DECISION AS TO WHETHER TO TENDER SHARES AND, IF SO, HOW MANY
SHARES TO TENDER.

     The Offer is being made to all holders of Shares solely pursuant to the
Offer to Purchase and the related Letter of Transmittal. This Offer is not being
made to (nor will any tender of Shares be accepted from or on behalf of) holders
in any jurisdiction in which the making of the Offer or the acceptance of any
tender of Shares therein would not be in compliance with the laws of such
jurisdiction. The Company may, at its discretion, take such action as it may
deem necessary for the Company to make the Offer in any such jurisdiction and
extend the Offer to holders in such jurisdiction. In any jurisdiction the
securities or blue sky laws of which require the Offer to be made by a licensed
broker or dealer, the Offer is being made on behalf of the Company by one or
more registered brokers or dealers which are licensed under the laws of such
jurisdiction.

     IN ORDER TO DIRECT THE TENDER OF 401(K) SHARES, YOU MUST COMPLETE, EXECUTE,
DETACH AND RETURN THE ATTACHED INSTRUCTION FORM TO THE AGENT IN AMPLE TIME TO
PERMIT US TO SUBMIT A TENDER ON YOUR BEHALF BY THE EXPIRATION OF THE OFFER AND
IN ANY EVENT NO LATER THAN 5:00 P.M., EASTERN

                                        2
<PAGE>   3

TIME, ON JANUARY 27, 2000. THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS
EXPIRE AT 5:00 P.M., EASTERN TIME, ON FEBRUARY 4, 2000, UNLESS THE COMPANY
EXTENDS THE OFFER. SHARES THAT ARE TENDERED AFTER THIS DEADLINE, AND SHARES THAT
ARE OTHERWISE INVALIDLY TENDERED, WILL NOT BE ACCEPTED. AN ENVELOPE TO RETURN
YOUR INSTRUCTION FORM TO THE AGENT IS ENCLOSED. IF YOU DIRECT US, THROUGH THE
AGENT, TO TENDER YOUR 401(K) SHARES, ALL SUCH SHARES WILL BE TENDERED UNLESS
OTHERWISE INDICATED ON THE ATTACHED INSTRUCTION FORM.

     As more fully described in the Offer to Purchase, tenders will be deemed
irrevocable unless withdrawn by the dates specified therein. If you instruct the
401(k) Plan Trustee, through the Agent, to tender 401(k) Shares, and you
subsequently decide to change your instructions, you may do so by submitting a
written notice of change of instruction to the Agent. The notice of change of
instruction will be effective only if it is received by the Agent AT OR BEFORE
5:00 P.M., EASTERN TIME, ON JANUARY 27, 2000. Upon receipt of a timely notice of
change of instruction to the Agent, previous instructions to tender with respect
to such Shares will be deemed canceled. If you later wish to re-tender Shares,
you may call the Agent at the above number and submit a new Instruction Form. If
you have any questions about the Offer or any of the other matters discussed
above, please call Corporate Investor Communications, Inc., the Information
Agent, at (877) 393-4959.

                                          Sincerely,

                                          Fidelity Management Trust Company

                                        3
<PAGE>   4

                                INSTRUCTION FORM
        FOR SHARES HELD BY FIDELITY MANAGEMENT TRUST COMPANY, AS TRUSTEE
                       OF THE GIANT INDUSTRIES, INC. AND
                   AFFILIATED COMPANIES 401(K) PLAN AND TRUST

                      INSTRUCTIONS FOR TENDER OF SHARES OF

                             GIANT INDUSTRIES, INC.

  THIS FORM IS TO BE RETURNED TO MANAGEMENT INFORMATION SYSTEMS, THE AGENT OF
  FIDELITY MANAGEMENT TRUST COMPANY (THE "AGENT"). AN ENVELOPE TO RETURN THIS
                   INSTRUCTION FORM TO THE AGENT IS ENCLOSED.

     The undersigned acknowledge(s) receipt of the letter from Fidelity
Management Trust Company, as trustee of the 401(k) Plan, and the enclosed Offer
to Purchase (the "Offer to Purchase") and the related Letter of Transmittal
(which, as amended or supplemented from time to time, together constitute the
"Offer") in connection with the offer by Giant Industries, Inc., a Delaware
corporation (the "Company"), to purchase up to 1,333,333 shares (or such lesser
number of shares as are validly tendered) of its common stock, $.01 par value
(the "Shares"), at $9.00 per Share, net to the seller in cash, without interest
thereon, upon the terms and subject to the conditions of the Offer.

     This will instruct you to tender to the Company, on (our) (my) behalf, the
proportion of 401(k) Shares indicated below (or if no number is indicated below,
all 401(k) Shares) that reflect units of the Stock Fund allocated to my 401(k)
Plan account, upon the terms and subject to the conditions of Offer.

PROPORTION OF 401(K) SHARES TO BE TENDERED THAT REFLECT UNITS OF THE STOCK FUND
                 ALLOCATED TO MY ACCOUNT (CANNOT EXCEED 100%):
                                     ____%*

  * Unless otherwise indicated, it will be assumed that all 401(k) Shares that
                           reflect units of the Stock
               Fund allocated to your account are to be tendered.

THE METHOD OF DELIVERY OF THIS DOCUMENT IS AT THE OPTION AND RISK OF THE
TENDERING 401(K) PLAN PARTICIPANT. IF DELIVERY IS BY MAIL, REGISTERED MAIL WITH
RETURN RECEIPT REQUESTED, PROPERLY INSURED, IS RECOMMENDED. IN ALL CASES,
SUFFICIENT TIME SHOULD BE ALLOWED TO ASSURE DELIVERY.

                                   SIGN HERE:

Signature(s):
- --------------------------------------------------------------------------------

Print Name(s):
- --------------------------------------------------------------------------------

Address(es):
- --------------------------------------------------------------------------------
                              (INCLUDING ZIP CODE)

Telephone Number:
- --------------------------------------------------------------------------------

Taxpayer Identification or Social Security Number:
- --------------------------------------------------------------------------------

Date:
- --------------------------------------------------------------------------------

<PAGE>   1

                                                                 EXHIBIT (A)(10)

                                 PRESS RELEASE

[GIANT INDUSTRIES, INC. LOGO]                           [GIANT LISTED NYSE LOGO]
NEWS
RELEASE                             Contact: Mark Cox, V.P., Treasurer, &
                                             Financial Officer
                                             Monte N. Swetnam, Executive V.P.
                                             Administration and Corporate
                                             Affairs
                                             (480)585-8888

FOR IMMEDIATE RELEASE

DECEMBER 21, 1999

                     GIANT INDUSTRIES, INC. ANNOUNCES PLAN
                       TO PURCHASE UP TO 1,333,333 SHARES

     SCOTTSDALE, AZ (DECEMBER 21, 1999) -- Giant Industries, Inc. [NYSE: GI]
today announced that it will commence a tender offer to purchase for cash up to
1,333,333 shares at a price of $9.00 per share. This represents approximately
12.9% of the Company's currently outstanding common stock. The offer will
commence today, Tuesday, December 21, 1999, and is set to expire at 5:00 p.m.
Eastern time on Friday, February 4, 2000.

     On December 20, 1999, the last trading day prior to the Offer, the price
per share for the last trade of the common stock on the New York Stock Exchange
was $7.00. The terms of the tender offer are described more fully in the Offer
to Purchase, Letter of Transmittal and related documents. The documents are
being mailed to the Company's shareholders in the next few days.

     Shareholders may obtain additional information about the Tender by
contacting the Information Agent, Corporate Investor Communications, Inc., at
(877) 393-4959.

     Giant Industries, Inc., headquartered in Scottsdale, Arizona, is a refiner
and marketer of petroleum products. Giant owns and operates two New Mexico crude
oil refineries, a 260 mile crude oil gathering pipeline system based in
Farmington which services the refineries, finished products distribution
terminals in Albuquerque, NM and Flagstaff, AZ, a fleet of 150 crude oil and
finished product truck transports, a Travel Center on I-40 east of Gallup, and a
chain of 168 retail service stations/convenience stores in New Mexico, Colorado,
Utah, and Arizona. Giant is also the parent company of Phoenix based Phoenix
Fuel Co., Inc., Arizona's largest independent petroleum products distributor.


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission